Technical Appendix for 1992 CLASSIFICATION OF DATA The principal value of vital statistics data is realized through the presentation of rates, which are computed by relating the vital events of a class to the population of a similarly defined class. Vital statistics and population statistics must therefore be classified according to similarly defined systems and tabulated in comparable groups. Even when the variables common to both, such as geographic area, age, sex, and race, have been similarly classified and tabulated, differences between the enumeration method of obtaining population data and the registration method of obtaining vital statistics data may result in significant discrepancies. The general rules used in the classification of geographic and personal items for deaths and fetal deaths for 1992 are set forth in two NCHS instruction manuals (2,3). A discussion of the classification of certain important items is presented below. Classification by occurrence and residence Tabulations for the United States and specified geographic areas in this volume are classified by place of residence unless stated as by place of occurrence. Before 1970 resident mortality statistics for the United States included all deaths occurring in the United States, with deaths of "nonresidents of the United States" assigned to place of death. "Deaths of nonresidents of the United States" refers to deaths that occur in the United States of nonresident aliens; nationals residing abroad; and residents of Puerto Rico, the Virgin Islands, Guam, and other territories of the United States. Beginning with 1970 deaths of nonresidents of the United States are not included in tables by place of residence. Tables by place of occurrence, on the other hand, include deaths of both residents and nonresidents of the United States. Consequently, for each year beginning with 1970, the total number of deaths in the United States by place of occurrence was somewhat greater than the total by place of residence. For 1992 this difference amounted to 3,574 deaths. Mortality statistics by place of occurrence are shown in tables 1-11, 1-19, 1-20, 1-30, 1-31, 1-32, 3-1, 3-6, 8-1, and 8-7. Before 1970 except for 1964 and 1965, deaths of nonresidents of the United States occurring in the United States were treated as deaths of residents of the exact places of occurrence, which in most instances was an urban area. In 1964 and 1965, deaths of nonresidents of the United States occurring in the United States were allocated as deaths of residents of the balance of the county in which they occurred. Residence error--Results of a 1960 study showed that the classification of residence information on the death certificates corresponded closely to the residence classification of the census records for the decedents whose records were matched (4). A comparison of the results of this study of deaths with those for a previous matched record study of births (5) showed that the quality of residence data had improved considerably between 1950 and 1960. Both studies found that events in urban areas were overstated by the NCHS classification in comparison with the U.S. Bureau of the Census - 1 - classification. The magnitude of the difference was substantially less for deaths in 1960 than it was for births in 1950. The improvement is attributed to an item added in 1956 to the U.S. Standard Certificates of Birth and of Death, asking whether residence was inside or outside city limits. This new item aided in properly allocating the residence of persons living near cities but outside the corporate limits. Although this may have improved the quality of data, accurate determination of place of residence appears to be a continuing problem. Geographic classification The rules followed in the classification of geographic areas for deaths and fetal deaths are contained in the two instruction manuals referred to previously (2,3). The geographic codes assigned by the NCHS during data reduction of source information on birth, death, and fetal-death records are given in another instruction manual (6). Beginning with 1982 data, the geographic codes were modified to reflect results of the 1980 census. For 1970-81 codes are based on results of the 1970 census. Metropolitan statistical areas--The Metropolitan statistical areas (MSA's) and Primary metropolitan statistical areas (PMSA's) used in this volume are those established by the U.S. Office of Management and Budget as of April 1, 1990, and used by the U.S. Bureau of the Census (7), except in the New England States. Outside the New England States, an MSA has either a city with a population of at least 50,000 or a U.S. Bureau of the Census urbanized area of at least 50,000 and a total MSA population of at least 100,000. A PMSA consists of a large urbanized county or cluster of counties that demonstrate very strong internal economic and social links and has a population over 1 million. When PMSA's are defined, the larger area of which they are component parts is designated a Consolidated Metropolitan Statistical Area (CMSA) (8). In the New England States, the U.S. Office of Management and Budget uses towns and cities rather than counties as geographic components of MSA's and PMSA's. However, NCHS cannot use this classification for these States because its data are not coded to identify all towns. Instead, NCHS uses New England County Metropolitan Areas (NECMA's). Made up of county units, these areas are established by the U.S. Office of Management and Budget (9). Metropolitan and nonmetropolitan counties--Independent cities and counties included in MSA's and PMSA's or in NECMA's are included in data for metropolitan counties; all other counties are classified as nonmetropolitan. Population-size groups--In 1992 vital statistics data for cities and certain other urban places were classified according to the population enumerated in the 1980 Census of Population. Data are available for individual cities and other urban places of 10,000 or more population. Data for the remaining areas not separately identified are shown in the tables under the heading "balance of area" or "balance of county." For the years 1970-81, classification of areas was determined by the population enumerated in the 1970 Census of Population. Beginning with 1982 data, some urban places identified in previous reports were deleted and others were added because of changes occurring in the enumerated population between 1970 and 1980. - 2 - Urban places other than incorporated cities for which vital statistics data are shown in this volume include the following: . Each town in New England, New York, and Wisconsin and each township in Michigan, New Jersey, and Pennsylvania that had no incorporated municipality as a subdivision and had either 25,000 inhabitants or more, or a population of 10,000 to 25,000 and a density of 1,000 persons or more per square mile. . Each county in States other than those indicated above that had no incorporated municipality within its boundary and had a density of 1,000 persons or more per square mile. (Arlington County, Virginia, is the only county classified as urban under this rule.) . Each place in Hawaii with a population of 10,000 or more. (There are no incorporated cities in the State.) Before 1964, places were classified as "urban" or "rural." The technical appendixes for earlier years discuss the previous classification system. State or country of birth Mortality statistics by State or country of birth (table 1-36) became available beginning with 1979. State or country of birth of a decedent is assigned to 1 of the 50 States or the District of Columbia; or to Puerto Rico, the Virgin Islands, or Guam--if specified on the death certificate. The place of birth is also tabulated for Canada, Cuba, Mexico, and for the Remainder of the World. Deaths for which information on State or country of birth was unknown, not stated, or not classifiable accounted for a small proportion of all deaths in 1992, about 0.6 percent. Early mortality reports published by the U.S. Bureau of the Census contained tables showing nativity of parents as well as nativity of decedent. Publication of these tables was discontinued in 1933. Mortality data showing nativity of decedent were again published in annual reports for 1939-41 and for 1950. Age The age recorded on the death record is the age at last birthday, the same as the age classification used by the U.S. Bureau of the Census. For 1992 data 474 death records (0.02 percent) contained not-stated age. For computation of age-specific and age-adjusted death rates, deaths with age not stated are excluded. For life table computation, deaths with age not stated are distributed proportionately. Race For vital statistics in the United States for 1992, deaths are classified by race--white, black, American Indian, Chinese, Hawaiian, Japanese, Filipino, and Other Asian or Pacific Islanders. Beginning in 1992 all records coded as "other races" (0.01 percent of the total deaths) were assigned to the specified race of the previous record. Mortality data for Filipino and Other Asian or Pacific Islander were shown for the first time in 1979. - 3 - The white category includes, in addition to persons reported as white, those reported as Mexican, Puerto Rican, Cuban, and all other Caucasians. The American Indian category includes American, Alaskan, Canadian, Eskimo, and Aleut. If the racial entry on the death certificate indicates a mixture of Hawaiian and any other race, the entry is coded to Hawaiian. If the race is given as a mixture of white and any other race, the entry is coded to the appropriate nonwhite race. If a mixture of races other than white is given (except Hawaiian), the entry is coded to the first race listed. This proce- dure for coding the first race listed has been used since 1969. Before 1969, if the entry for race was a mixture of black and any other race except Hawaiian, the entry was coded to black. Most of the tables in this volume, however, do not show data for this detailed classification by race. Most tables show data for white, all other (including black), and black separately. Race not stated--For 1992 the number of death records for which race was unknown, not stated, or not classifiable was 5,776 or 0.3 percent of the total deaths. Beginning in 1992 death records with race entry not stated were assigned to the specified race of the previous record with known race. From 1965 to 1991 death records with race entry not stated were assigned to a racial designation as follows: If the preceding record was coded white, the code assignment was made to white; if the code was other than white, the assignment was made to black. Before 1964 all records with race not stated were assigned to white except records of residents of New Jersey for 1962-64. New Jersey, 1962-64--New Jersey omitted the race item from its certificates of live birth, death, and fetal death used in the beginning of 1962. The item was restored during the latter part of 1962. However, the certificate revision without the race item was used for most of 1962 as well as 1963. Therefore, figures by race for 1962 and 1963 exclude New Jersey. For 1964 6.8 percent of the death records used for residents of New Jersey did not contain the race item. Adjustments made in vital statistics to account for the omission of the race item in New Jersey for part of the certificates filed during 1962-64 are described in the Technical Appendix of the Vital Statistics of the United States for each of those data years. Quality of race data--A number of studies have been conducted on the reliability of race reported on the death certificate. These studies compare race reported on the death certificate with that reported on another data collection instrument such as the census or a survey. Race information on the death certificate is reported by the funeral director as provided by an informant, often the surviving next of kin, or, in the absence of an informant, on the basis of observation. In contrast, race on the census or the Current Population Survey (CPS) is self-reported and, therefore, may be considered more valid. A high level of agreement between the death certificate and the census or survey report is essential to ensure unbiased death rates by race. In one study a sample of approximately 340,000 death certificates was compared with census records for a 4-month period in 1960 (10). Percent agreement was 99.8 percent for white decedents, and 98.2 percent for black decedents; but less for the smaller minority groups (table A). In another study 29,713 death certificates were compared with responses to the race questions from a total of 12 CPS's conducted by the U.S. Bureau of the Census for the years 1979-85 (11). In this study, entitled the National Longitudinal Mortality Study, agreement for white decedents was 99.2 and for - 4 - black 98.2; agreement was less for the smaller race groups. In 1986 the National Mortality Followback Survey, conducted by NCHS, listed a question about the race of decedents 25 years old and over. The total sample was 18,733 decedents (12). The rates of agreement were similar to those observed in the other studies. All of these studies show that persons self-reported as American Indian or Asian on census and survey records (and by informants in the Followback Survey) were sometimes reported as white on the death certificate. The net effect of misclassification is an underestimation of deaths and death rates for the smaller minority races. Table A. Comparison of percent agreement and ratio of deaths for census or survey record to deaths by race for matching death certificate: 1960 and 1979-85 _____________________________________________________________________________ Census NLMS1/ _______________________ ___________________ Ratio Ratio Percent census/death Percent NLMS/death Race agreement certificate agreement certificate _____________________________________________________________________________ White 99.8 1.00 99.2 1.00 Black 98.2 1.00 98.2 1.00 American Indian 79.2 1.12 73.6 1.22 Asian --- ... 82.4 1.12 Japanese 97.0 1.04 ... ... Chinese 90.3 1.07 ... ... Filipino 72.6 1.28 ... ... _____________________________________________________________________________ ---Data not available. ...Category not applicable. 1/ NLMS is defined as National Longitudinal Mortality Study. SOURCES: Hambright TZ. Comparability of marital status, race, nativity, and country of origin on the death certificate and matching census record: U.S., May-August 1960. National Center for Health Statistics. Vital Health Stat 2(34). 1969; Sorlie PD, Rogot E, Johnson NJ. Validity of demographic characteristics on the death certificate. Epidemiology 3(2):181-4. 1992. Hispanic origin Mortality statistics for the Hispanic-origin population are based on information for those States and the District of Columbia that included items on the death certificate to identify Hispanic or ethnic origin of decedents. Data for 1992 were obtained from the District of Columbia and all States except New Hampshire and Oklahoma, which were excluded because their death certificates did not include an item to identify Hispanic or ethnic origin. Hispanic mortality data were published for the first time in 1984. Generally, the reporting States used items similar to one of two basic formats recommended by NCHS. The first format is directed specifically toward the Hispanic population and appears on the U.S. Standard Certificate of Death as follows: - 5 - Was decedent of Hispanic origin? (Specify No or Yes--If Yes, specify Cuban, Mexican, Puerto Rican, etc.) ___ No ___ Yes Specify: The second format is a more general ancestry item and appears as follows: Ancestry--Mexican, Puerto Rican, Cuban, African, English, Irish, German, Hmong, etc., (specify) The 48 States and the District of Columbia for which general mortality data are shown in this report accounted for about 99.6 percent of the Hispanic population in the United States in 1990. This included about 99.5 percent of the Mexican population, 99.7 percent of the Puerto Rican population, 99.8 percent of the Cuban population, and 99.6 percent of the "Other Hispanic" population (13). For qualifications regarding infant mortality of the Hispanic-origin population, see "Infant deaths." Connecticut--For deaths occurring in Connecticut in 1991, a number of deaths were erroneously coded. For Mexicans there should have been 7 deaths, not 318 deaths; and for Puerto Ricans, there should have been 371 deaths, not 215 deaths. As a result, the number of deaths for the 47 States, New York (excluding New York City), and the District of Columbia for Mexicans should be about 1 percent less and the number for Puerto Ricans should be about 3 percent more than the figures shown. Quality of data on Hispanic origin--A recent study (11) examined the reliability of Hispanic origin reported on 43,520 death certificates with that reported on a total of 12 CPS's conducted by the U.S. Bureau of the Census for the years 1979-85. In this study, agreement was 89.7 percent for any report of Hispanic origin. The ratio of deaths for CPS divided by deaths for death certificate was 1.07 percent indicating net underreporting of Hispanic origin on death certificates as compared with self-reports on the surveys. The sample was too small to assess the reliability of specified Hispanic groups. Marital status Mortality statistics by marital status (tables 1-34 and 1-35) have been published annually since 1979. They were previously published in the annual volumes for 1949-51 and 1959-61. Several reports analyzing mortality by marital status have been published, including the special study based on 1959-61 data (14). Reference to earlier reports is given in the appendix of part B of the 1959-61 special study. Mortality statistics by marital status are tabulated separately for never married, married, widowed, and divorced. Certificates on which the marriage is specified as being annulled are classified as never married. Where marital status is specified as separated or common-law marriage, it is classified as married. Of the 2,125,554 resident deaths 15 years of age and over in 1992, 9,696 certificates (0.5 percent) had marital status not stated. - 6 - Educational attainment Beginning with the 1989 data year, mortality data on educational attainment are being tabulated from information reported on the death certificate. As a result of the revisions of the U.S. Standard Certificate of Death (1), this item was added to the certificates of a large number of States: . Decedent's Education (specify only highest grade completed) . Elementary/Secondary (0-12) College (1-4 or 5+) Mortality data on educational attainment for 1992 (table 1-45) are based on deaths to residents of 45 States, New York (excluding New York City), and the District of Columbia. Data for four States--Georgia, Oklahoma, Rhode Island, and South Dakota--are excluded from this table because their death certificates did not include an educational attainment item; and data for New York City are excluded because the education item on its death certificate was considered not comparable to be used for analysis. In tables 1-46 and 1-47, the data are based on deaths to residents of 42 States and the District of Columbia whose data were approximately 80- percent or more complete on a place-of-occurrence basis. In addition to the four States mentioned previously, data from Connecticut, Kentucky, and West Virginia were excluded because more than 20 percent of their death certificates were classified to "unknown educational attainment." In addition, data for New York were excluded because data for New York City were considered not comparable to data from the other areas. Place of death and status of decedent Mortality statistics by place of death have been published annually since 1979. Before that year they were published in 1958 (tables 1-30--1-32). In addition, mortality data also were available for the first time in 1979 for the status of decedent when death occurred in a hospital or medical center. The 1992 data were obtained from the following two items appearing on the revised U.S. Standard Certificate of Death (1): . Item 9a. Place of Death (check only one) Hospital: Inpatient, ER/Outpatient, DOA Other: Nursing Home, Residence, Other (specify) . Item 9b. Facility Name (If not institution, give street and number) Before the 1989 revision of the Standard Certificate of Death, information on place of death and status of decedent could be determined if the hospital or institution indicated Inpatient, Outpatient, ER, and DOA, and if the name of the hospital or institution, which was used to determine the kind of facility, appeared on the certificate. The change to a checkbox format in many States for this item may affect the comparability of data between 1989 and subsequent years and that for years before 1989. - 7 - Except for Oklahoma, all of the States (including New York City) and the District of Columbia have item 9 (or its equivalent) on their certificates. For all reporting States and the District of Columbia in the VSCP, NCHS accepts the state definition, classification, or code for hospitals, medical centers, nursing homes, or other institutions. Effective with data year 1980, the coding for place of death and status of decedent was modified. A new coding category was added: "Death on arrival--hospital, clinic, medical center name not given." Deaths coded to this category are tabulated in tables 1-30--1-32. Had the 1979 coding categories been used, these deaths would have been tabulated as "Place unknown." California--For the first five months of data year 1989, California coded "residence" to "other" for "Place of death." Mortality by month and date of death Deaths by month have been tabulated regularly and published in the annual volume for each year beginning with data year 1900. For 1992 deaths by month are shown in tables 1-20, 1-21, 1-24, 1-33, 2-16--2-18, and 3-7. Date of death was published for the first time for data year 1972. In addition, unpublished data for selected causes by date of death for 1962 are available from NCHS. Numbers of deaths by date of death in this volume are shown in table 1-33 for the total number of deaths and for the numbers of deaths for the following three causes, for which the greatest interest in date of occurrence of death has been expressed: Motor vehicle accidents, Suicide, and Homicide and legal intervention. These data show the frequency distribution of deaths for the selected causes by day of week. They also make it possible to identify holidays with peak numbers of deaths from specified causes. Report of autopsy Before 1972 the last year for which autopsy data were tabulated was 1958. Beginning in 1972 all registration areas requested information on the death certificates as to whether an autopsy was performed. For 1992 autopsies were reported on 224,071 death certificates, 10.3 percent of the total (table 1-29). For six of the cause-of-death categories shown in table 1-29, autopsies were reported as performed for 50 percent or more of all deaths (Pregnancy with abortive outcome; Other complications of pregnancy, childbirth, and the puerperium; Motor vehicle accidents; Suicide; Homicide and legal intervention; and All other external causes). Autopsies were reported for only 6.6 percent of the Major cardiovascular diseases. - 8 - Cause of death Cause-of-death classification--Since 1949, cause-of-death statistics have been based on the underlying cause of death, which is defined as "(a) the disease or injury which initiated the train of events leading directly to death, or (b) the circumstances of the accident or violence which produced the fatal injury" (15). For each death the underlying cause is selected from an array of conditions reported in the medical certification section on the death certificate. This section provides a format for entering the cause of death sequentially. The conditions are translated into medical codes through use of the classification structure and the selection and modification rules contained in the applicable revision of the International Classification of Diseases (ICD), published by the World Health Organization (WHO). Selection rules provide guidance for systematically identifying the underlying cause of death. Modification rules are intended to improve the usefulness of mortality statistics by giving preference to certain classification categories over others and/or to consolidate two conditions or more on the certificate into one classification category. As a statistical datum, underlying cause of death is a simple, one-dimensional statistic; it is conceptually easy to understand and a well-accepted measure of mortality. It identifies the initiating cause of death and is therefore most useful to public health officials in developing measures to prevent the onset of the chain of events leading to death. The rules for selecting the underlying cause of death are included in ICD as a means of standardizing classification, which contributes toward comparability and uniformity in mortality medical statistics among countries. Tabulation lists--Beginning with data year 1979, the cause-of-death statistics published by NCHS have been classified according to the Ninth Revision of the International Classification of Diseases (15). In addition to specifying that ICD-9 be used, WHO also recommends how the data should be tabulated to promote international comparability. The recommended system for tabulating data in ICD-9 allows countries to construct their mortality and morbidity tabulation lists from the rubrics of the WHO Basic Tabulation List (BTL) if the rubrics from the WHO mortality and morbidity lists, respectively, are included. This tabulation system for the Ninth Revision is more flexible than that of the Eighth Revision, in which specific lists were recommended for tabulating mortality and morbidity data. The BTL recommended under the Ninth Revision consists of 57 two-digit rubrics that when added equal the "all causes" total. Identified within each two-digit rubric are up to nine three-digit rubrics that are numbered from zero to eight and whose total does not equal the two-digit rubric. The two-digit BTL rubrics 01-46 are used for the tabulation of nonviolent deaths according to ICD categories 001-799. Rubrics relating to chapter 17 (nature-of-injury causes 47-56) are not used by NCHS for selecting underlying cause of death; rather, preference is given to rubrics E47-E56. The 57th two-digit rubric (VO) - 9 - is the Supplementary Classification of Factors Influencing Health Status and Contact with Health Services and is not appropriate for the tabulation of mortality data. The WHO Mortality List, a subset of the titles contained in the BTL, consists of 50 rubrics that are the minimum necessary for the national display of mortality data. Five lists of causes have been developed for tabulation and publication of mortality data in this volume--the Each-Cause List, List of 282 Selected Causes of Death, List of 72 Selected Causes of Death, List of 61 Selected Causes of Infant Death, and List of 34 Selected Causes of Death. These lists were designed to be as comparable as possible with the NCHS lists used under the Eighth Revision. However, complete comparability could not always be achieved. The Each-Cause List is made up of each three-digit category of the WHO Detailed List to which deaths may be validly assigned and most four-digit subcategories. The list is used for tabulation for the entire United States. The published Each-Cause table does not show the four-digit subcategories provided for Motor vehicle accidents (E810-E825); however, these subcategories that identify persons injured are shown in the accident tables of this report (section 5). Special fifth-digit subcategories also are used in the accident tables to identify place of accident when deaths from nontransport accidents are shown. These are not shown in the Each-Cause table. The List of 282 Selected Causes of Death is constructed from BTL rubrics 01-46 and E47-E56. Each of the 56 BTL two-digit titles can be obtained either directly or by combining titles in the List. The three-digit level of the BTL is modified more extensively. Where more detail was desired, categories not shown in the three-digit rubrics were added to the List of 282 Selected Causes of Death. Where less detail was needed, the three-digit rubrics were combined. Moreover, each of the 50 rubrics of the WHO Mortality List can be obtained from the List of 282 Selected Causes of Death. The List of 72 Selected Causes of Death was constructed by combining titles in the List of 282 Selected Causes of Death. It is used in tables published for the United States and each State and for Metropolitan statistical areas. The List of 61 Selected Causes of Infant Death shows more detailed titles for Congenital anomalies and Certain conditions originating in the perinatal period than any other list except the Each-Cause List. The List of 34 Selected Causes of Death was created by combining titles in the List of 72 Selected Causes. A table using this list is published for detailed geographic areas. Beginning with data for 1987, changes were made in these lists to accommodate the introduction in the United States of new categories *042-*044 for Human immunodeficiency virus (HIV) infection. The changes are described in the Technical Appendix from Vital Statistics for the United States, 1987. Effect of list revisions--The International Lists or adaptations of them, used in the United States since 1900, have been revised approximately every 10 years so the disease classifications may be consistent with advances in medical science and with changes in diagnostic practice. Each revision of the International Lists has produced some break in comparability of cause-of-death statistics. - 10 - Cause-of-death statistics beginning with 1979 are classified by NCHS according to the ICD-9 (15). For a discussion of each of the classifications used with death statistics since 1900, see Vital Statistics of the United States, 1979, Volume II, Mortality, Part A, section 7, pages 9-14. A dual coding study was undertaken in which the Ninth and the Eighth Revisions were compared to measure the extent of discontinuity in cause-of- death statistics resulting from introducing the new revision. A study for the List of 72 Selected Causes of Death and the List of 10 Selected Causes of Infant Death has been published (16). The List of 10 Selected Causes of Infant Death is a basic NCHS tabulation list not used in this volume but used for provisional data in the Monthly Vital Statistics Report, another NCHS publication. Comparability studies were also undertaken between the Eighth and Seventh, Seventh and Sixth, and Sixth and Fifth Revisions. For additional information about these studies, see the Technical Appendix from Vital Statistics for the United States, 1979. Significant coding changes under the Ninth Revision--Since the implementation of ICD-9 in the United States, effective with mortality data for 1979, several coding changes have been introduced. The more important changes are discussed as follows: In early 1983 a change that affected data from 1981 to 1986 was made in the coding of Acquired immunodeficiency syndrome (AIDS) and HIV infection. Also effective with data year 1981 was a coding change for Poliomyelitis. For data year 1982, the definition of child was changed (which affects the classification of deaths to a number of categories, including Child battering and other maltreatment), and guidelines for coding deaths to the category Child battering and other maltreatment (ICD No. E967) were changed also. During the calendar year 1985, detailed instructions for coding Motor vehicle accidents involving all-terrain vehicles were implemented to ensure consistency in coding these accidents. Effective with data year 1986, "Primary" and "Invasive" tumors, unspecified, were classified as "Malignant;" these neoplasms had been classified to Neoplasms of unspecified nature (ICD-9 No. 239). Beginning with data for 1987, NCHS introduced new category numbers *042-*044 for classifying and coding HIV infection, formerly referred to as Human T-cell lymphotropic virus-III/lymphadenopathy associated virus (HTLV-III/LAV) infection. The asterisks appearing before the categories indicate these codes are not part of ICD-9. Also changed effective with data year 1987 were coding rules for the conditions "Dehydration" and "Disseminated intravascular coagulopathy." Effective with data year 1988, minor content changes were made to the classification for HIV infection. Detailed discussion of these changes may be found in the Technical Appendix for previous volumes. Coding in 1992--The rules and instructions used in coding the 1992 mortality medical data remained essentially the same as those used for the 1990 and 1991 data. - 11 - Medical certification--The use of a standard classification list, although essential for State, regional, and international comparison, does not ensure strict comparability of the tabulated figures. A high degree of comparability among areas could be attained only if all records of cause of death were reported with equal accuracy and completeness. The medical certification of cause of death can be made only by a qualified person, usually a physician, a medical examiner, or a coroner. Therefore, the reliability and accuracy of cause-of-death statistics are, to a large extent, governed by the ability of the certifier to make the proper diagnosis and by the care with which he or she records this information on the death certificate. A number of studies have been undertaken on the quality of medical certification on the death certificate. In general, these have been for relatively small samples and for limited geographic areas. A bibliography prepared by NCHS (17), covering 128 references over 23 years, indicates no definitive conclusions have been reached about the quality of medical certification on the death certificate. No country has a well-defined program for systematically assessing the quality of medical certifications reported on death certificates or for measuring the error effects on the levels and trends of cause-of-death statistics. One index of the quality of reporting causes of death is the proportion of death certificates coded to the Ninth Revision, Chapter XVI, Symptoms, signs, and ill-defined conditions (ICD-9 Nos. 780-799). Although deaths occur for which it is impossible to determine the underlying cause, this proportion indicates the care and consideration given to the certification by the medical certifier. This proportion also may be used as a rough measure of the specificity of the medical diagnoses made by the certifier in various areas. In 1992 a record low of 1.1 percent of all reported deaths in the United States were assigned to this category the same as in 1991. The percent of deaths assigned to this category remained stable at 1.5 percent from 1981 to 1987, but has declined slightly since then. However, trends in the percent of deaths assigned to this category vary by age. Declines since the early 1980's have been most rapid for the 10-year age groups between ages 55-84. Automated selection of underlying cause of death--Before data for 1968, mortality medical data were based on manual coding of an underlying cause of death for each certificate in accordance with WHO rules. Effective with data year 1968, NCHS converted to computerized coding of the underlying cause and manual coding of all causes (multiple causes) on the death certificate. In this system, called Automated Classification of Medical Entities (ACME) (18), the multiple cause codes serve as inputs to the computer software that employs WHO rules to select the underlying cause. Many States also have implemented ACME and provide multiple cause and underlying cause data to NCHS in electronic form. The ACME system applies the same rules for selecting the underlying cause as would be applied manually by a nosologist; however, under this system, the computer consistently applies the same criteria, thus eliminating intercoder variation in this step of the process. - 12 - The ACME computer program requires the coding of all conditions shown on the medical certification. These codes are matched automatically against decision tables that consistently select the underlying cause of death for each record according to the international rules. The decision tables provide the comprehensive relationships among the conditions classified by ICD when applying the rules of selection and modification. The decision tables were developed by NCHS staff on the basis of their experience in coding underlying causes of death under the earlier manual coding system and as a result of periodic independent validations. These tables periodically are updated to reflect additional new information on the relationship among medical conditions. For data year 1988, these tables were amended to incorporate minor changes to the previously mentioned classification for HIV infection (*042-*044) that originally had been implemented with data year 1987. Coding procedures for selecting the underlying cause of death by using the ACME computer program, as well as by using the ACME decision tables, are documented in NCHS instruction manuals (18,22,23). Beginning with data year 1990, another computer system was implemented for automating cause-of-death coding. This system, called Mortality Medical Indexing, Classification, and Retrieval (MICAR) (19,20), automates coding multiple causes of death. Because MICAR automates coding rules, errors in recognizing terms, applying coding rules, and using the ICD index are eliminated. The use of the MICAR system ensures consistent application of coding rules, which is especially important for rules that are complex and infrequently applied. In addition, MICAR ultimately will provide more detailed information on the conditions reported on the death certificates than is available through the ICD category structure (21). In the first year of implementation, only about 5 percent (94,372) of the Nation's death records were coded using MICAR with subsequent processing through ACME. This percentage increased from 26 percent (573,416) in 1991 to approximately 35 percent (800,000) of the Nation's deaths in 1992. (See "Death and fetal- death statistics" and "Medical items on the death certificate.") Cause-of-death ranking--Cause-of-death ranking except for infants is based on numbers of deaths assigned to categories in the List of 72 Selected Causes of Death and the category Human immunodeficiency virus infection (*042-*044); cause-of-death ranking for infants is based on the List of 61 Selected Causes of Infant Death and HIV infection. HIV infection was added to the list of rankable causes effective with data year 1987. The group titles Major cardiovascular diseases and Symptoms, signs, and ill-defined conditions from the List of 72 Selected Causes of Death are not ranked; Certain conditions originating in the perinatal period and Symptoms, signs, and ill-defined conditions from the List of 61 Selected Causes of Infant Death are not ranked. In addition, category titles beginning with the words "Other" or "All other" are not ranked to determine the leading causes of death. When one of the titles representing a subtotal is ranked (such as Tuberculosis), its component parts (in this case, Tuberculosis of respiratory system and Other tuberculosis) are not ranked. - 13 - Maternal deaths Maternal deaths are those for which the certifying physician has designated a maternal condition as the underlying cause of death. Maternal conditions are those assigned to Complications of pregnancy, childbirth, and the puerperium (ICD-9 Nos. 630-676). In the Ninth Revision, WHO for the first time defined a maternal death as follows: A maternal death is defined as the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and the site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes. Under the Eighth Revision, maternal deaths were assigned to the category "Complications of pregnancy, childbirth, and the puerperium" (ICDA-8 Nos. 630-678). Although WHO did not define maternal mortality, an NCHS classification rule existed that limited the definition of a maternal death to a death that occurred within a year after termination of pregnancy from any "maternal cause," that is, any cause within the range of ICDA-8 Nos. 630-678. This rule applied only if a duration was given for the condition. If no duration was specified and the underlying cause of death was a maternal condition, the duration was assumed to be within a year and the death was coded by NCHS as a maternal death. The change from an under-1-year limitation for duration used in the Eighth Revision to an under-42-days limitation used in the Ninth Revision did not have much effect on the comparability of maternal mortality statistics. However, comparability was affected by the following classification change. Under the Ninth Revision, maternal causes of death have been expanded to include Indirect obstetric causes (ICD-9 Nos. 647-648). These causes include Infective and parasitic conditions as well as other conditions present in the mother and classifiable elsewhere but that complicate pregnancy, childbirth, and the puerperium, such as Syphilis, Tuberculosis, Diabetes mellitus, Drug dependence, and Congenital cardiovascular disorders. Maternal mortality rates are computed on the basis of the number of live births. The maternal mortality rate indicates the likelihood of a pregnant woman dying of maternal causes. The number of live births used in the denominator is an approximation of the population of pregnant women who are at risk of a maternal death. Race--Beginning with the 1989 data year, NCHS changed the method of tabulating live birth and fetal death data by race from race of child to race of mother. This resulted in a discontinuity in maternal mortality rates by race between 1989-92 and previous years; see "Change in tabulation of race data for live births and fetal deaths," under "Infant deaths" in the Technical Appendix from Vital Statistics of the United States, 1990, or the series report, "Effect on Mortality Rates of the 1989 Change in Tabulating Race" (24). - 14 - Infant deaths Age--Infant death is defined as a death under 1 year of age. The term excludes fetal deaths. Infant deaths usually are divided into two categories according to age, neonatal and postneonatal. Neonatal deaths are those that occur during the first 27 days of life; postneonatal deaths are those that occur between 28 days and 1 year of age. Generally, it has been believed that different factors influencing the child's survival predominate in these two periods: Factors associated with prenatal development, heredity, and the birth process were considered dominant in the neonatal period; environmental factors, such as nutrition, hygiene, and accidents, were considered more important in the postneonatal period. Recently, however, the distinction between these two periods has blurred due in part to advances in neonatology, which have enabled more very small premature infants to survive the neonatal period. Rates--Infant mortality rates shown in sections 2 and 8 are the most commonly used indices for measuring the risk of dying during the first year of life; they are calculated by dividing the number of infant deaths in a calendar year by the number of live births registered for the same period and are presented as rates per 1,000 or per 100,000 live births. Infant mortality rates use the number of live births in the denominator to approximate the population at risk of dying before the first birthday. This measure is an approximation because some live births will not have been exposed to a full year's risk of dying and some of the infants who die during a year will have been born in the previous year. The error introduced in the infant mortality rate by this inexactness is usually small, especially when the birth rate is relatively constant from year to year (25,26). Other sources of error in the infant mortality rate have been attributed to differences in applying the definitions for infant death and fetal death when registering the event (27,28,29). In contrast to infant mortality rates based on live births, infant death rates shown in section 1 are based on the estimated population under 1 year of age. Infant death rates, which appear in tabulations of age-specific death rates, are calculated by dividing the number of infant deaths in a calendar year by the estimated midyear population of persons under 1 year of age and are presented as rates per 100,000 population in this age group. Patterns and trends in the infant death rate may differ somewhat from those of the more commonly used "infant mortality rate," mainly because of differences in the nature of the denominator and in the time reference. Whereas the population denominator for the infant death rate is estimated using data on births, infant deaths, and migration for the 12-month period of July-June, the denominator for the infant mortality rate is a count of births occurring during the 12 months of January-December. The difference in the time reference can result in different trends between the two indices during periods when birth rates are moving up or down markedly. The infant death rate also is subject to greater imprecision than is the infant mortality rate because of problems of enumerating and estimating the population under 1 year of age (28). - 15 - Change in tabulation of race data for live births and fetal deaths--Beginning with the 1989 data year, NCHS changed the method of tabulating live-birth and fetal-death data by race from race of child to race of mother. As in previous years, race for infant and maternal deaths (the numerator of the rate) is tabulated by the race of the decedent. Because live births comprise the denominator of infant and maternal mortality rates, this change resulted in a discontinuity in rates between 1989-92 data, and that for previous years. For fetal and perinatal mortality rates, the numerator and the denominator of the rates are affected, resulting in a slightly smaller discontinuity. For additional information, see the Technical Appendix from Vital Statistics of the United States, 1990 or the series report, "Effect on Mortality Rates of the 1989 Change in Tabulating Race" (24). Comparison of race data from birth and death certificates--Regardless of whether vital events are tabulated by race of mother or by race of child, inconsistencies exist in reporting race for the same infant between birth and death certificates, based on results of studies in which race on the birth and death certificates for the same infant were compared (30). These reporting inconsistencies can result in systematic biases in infant mortality rates by specified race, in particular, underestimates for specified races other than white or black. In the computation of race-specific infant mortality rates published in Vital Statistics of the United States, the race item for the numerator comes from the death certificate, and for the denominator, from the birth certificate. Biases in the rates may arise because of possible inconsistencies in reporting race on these two vital records. Race of the mother and father is reported on the birth certificate by the mother at the time of delivery; whereas race of the deceased infant is reported on the death certificate by the funeral director based on observation or on information supplied by an informant, such as a parent. Previous studies have noted that the race for an infant who died and was of a smaller minority race group is sometimes reported as white on the death certificate but is reported as the minority race group on the birth certificate, resulting, in the aggregate, in understatement of infant mortality for smaller race groups (30). Estimates can be made of the degree of bias in race-specific infant mortality rates by comparing rates for birth cohorts based on the linked birth and infant death data set (31,32) with period rates based on mortality data published in Vital Statistics of the United States for the same year(s). The comparison of cohort and period rates is somewhat affected by small differences in the events included in the numerators of the two rates. The numerator of the cohort rate is comprised of infant deaths to the cohort of infants born in a calendar year whereas the numerator of the period rate is comprised of infant deaths occurring in the calendar year. Based on data comparing infant mortality rates from the linked data set for the birth cohorts of 1989-91 with period rates constructed for 1989-91, bias in the rates for the two major race groups--white and black--is small (table B). However, cohort rates for the smaller race groups are estimated to be higher than period rates by 2 to 56 percent. - 16 - Table B. Infant mortality rates by race of mother for the period 1989-91 and for birth cohorts, 1989-91; and ratio of birth cohort to period rates: United States [Rates per 1,000 live births in specified groups] _____________________________________________________________________________ Period Birth Ratio rate cohort rate cohort/ Race 1989-91 1989-91 period rates _____________________________________________________________________________ All races 9.3 9.0 0.97 White 7.6 7.4 0.97 Black 18.0 17.1 0.95 American Indian 11.2 12.6 1.13 Chinese 5.0 5.1 1.02 Japanese 4.4 5.3 1.20 Hawaiian 10.9 9.0 0.83 Filipino 4.1 6.4 1.56 Other Asian or Pacific Islander 5.6 7.0 1.25 _____________________________________________________________________________ NOTE: Births for race not stated are not distributed. The exception to this pattern is for Hawaiians, where cohort rates are 17 percent lower than period rates. This may reflect the slightly different race coding rules used for Hawaiians than those used for other races (see "Race" under "Classification of Data"). For mortality data, in cases of mixed Hawaiian and other race parentage, race is always classified as "Hawaiian." In contrast, the race data from the birth certificate is classified according to the race of the mother. The race data from the birth certificate is used in the denominator of period infant mortality rates, and in the numerator and denominator of cohort infant mortality rates. This difference leads to slightly fewer infant deaths being classified as Hawaiian in the cohort data, compared to the period data. The cohort infant mortality rate for Hawaiians is considered to be more accurate, because the numerator and denominator data come from the same data source and are coded in the same manner. Cohort infant mortality rates from the linked file have not been adjusted to reflect the 2 to 3 percent of infant death records that were not linked to their corresponding birth records. Because of systematic understatement of infant mortality rates based on period data, data from the national linked files should be used to measure infant mortality for races other than black and white. For the black and white populations, period data are a close approximation of the rates based on linked files. Hispanic origin--Infant mortality rates for the Hispanic-origin population are based on numbers of resident infant deaths reported to be of Hispanic origin (see "Hispanic origin") and numbers of resident live births by Hispanic origin of mother for the 48 States and the District of Columbia. Data for New Hampshire and Oklahoma were excluded because these States did not include an item on Hispanic origin on their death certificates. In computing infant mortality rates, deaths and live births of unknown origin are not distributed among the specified Hispanic and non-Hispanic groups. Because the percent of infant deaths of unknown origin for 1992 was 2.4 - 17 - percent and the percent of live births of unknown origin was 1.0 percent, infant mortality rates by specified Hispanic origin and race for non-Hispanic origin may be slightly underestimated. Small numbers of infant deaths for specific Hispanic-origin groups can result in infant mortality rates subject to relatively large random variation (see "Random variation in numbers of deaths, death rates, and mortality rates and ratios"). Tabulation list--Causes of death for infants are tabulated according to a list of causes that is different from the list of causes for the population of all ages, except for the Each Cause List. (See "Cause-of-death classification" under "Cause of death.") Fetal deaths In May 1950 WHO recommended the following definition of fetal death be adopted for international use: Death prior to the complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of pregnancy; the death is indicated by the fact that after such separation, the fetus does not breathe or show any other evidence of life such as beating of the heart, pulsation of the umbilical cord, or definite movement of voluntary muscles (33). The term "fetal death" was defined on an all-inclusive basis to end confusion arising from the use of such terms as stillbirth, spontaneous abortion, and miscarriage. Shortly thereafter, this definition was adopted by NCHS as the nationally recommended standard. All registration areas except Puerto Rico have definitions similar to the standard definition (34). Puerto Rico has no formal definition. As another step toward increasing comparability of data on fetal deaths for different countries, WHO recommended that for statistical purposes fetal deaths be classified as early, intermediate, and late. These groups are defined as follows: Less than 20 completed weeks of gestation (early fetal deaths)...........................Group I 20 completed weeks of gestation but less than 28 (intermediate fetal deaths).................Group II 28 completed weeks of gestation and over (late fetal deaths)............................Group III Gestation period not classifiable in groups I, II, and III.................................Group IV As shown in table 3-11, group IV consists of fetal deaths with gestation not stated but presumed to be 20 weeks or more. Until 1939 the nationally recommended procedure for registration of a fetal death required the filing of a live-birth certificate and a death certificate. In 1939 a separate Standard Certificate of Stillbirth (fetal death) was created to replace the former procedure. This was revised - 18 - in 1949, 1956, 1968, 1978, and 1989. The 1989 U.S. Standard Report of Fetal Death is shown in figure 7-B. The 1977 revision of the Model State Vital Statistics Act and Model State Vital Statistics Regulations (35) recommended spontaneous fetal deaths at a gestation of 20 weeks or more or a weight of 350 grams or more be reported and further be reported on separate forms. These should be considered legally required statistical reports rather than legal documents. The 1992 revision of the Model State Vital Statistics Act and Regulations (36) recommended all spontaneous fetal deaths weighing 350 grams or more or if weight is unknown, fetal deaths of 20 completed weeks of gestation be reported. Beginning with fetal deaths reported in 1970, procedures were implemented that attempted to separate reports of spontaneous fetal deaths from those of induced terminations of pregnancy. These procedures were implemented because the health implications of spontaneous fetal deaths are different from those of induced terminations of pregnancy. These procedures are still used. Comparability and completeness of data--Registration area requirements for reporting fetal deaths vary. Most of the areas require reporting of fetal death at gestations of 20 weeks or more. Table C shows the minimum period of gestation required by each State to report fetal death in 1992. Substantial evidence exists that indicates some fetal deaths for which reporting is required are not reported (37,38). Table C. Period of gestation at which fetal-death reporting is required: Each reporting area, 1992 ______________________________________________________________________________ |All | | |20 |20 |20 | | | |periods| | |weeks |weeks |weeks | | | |of | 16 | 20 |or |or |or |5 | 350 | 500 |gesta- | wks | wks |350 |400 |500 |mos.|grams|grams Area |tion | | |grams |grams |grams | | | ____________________|_______|_____|_____|______|______|______|____|_____|_____ Alabama | | | X | | | | | | Alaska | | | X | | | | | | Arizona | | | 1X | | | | | | Arkansas | 2X | | | | | | | | California | | | X | | | | | | Colorado | 2X | | | | | | | | Connecticut | | | X | | | | | | Delaware | | | | | | | | 3X | District of Columbia| | | | | | X | | | Florida | | | X | | | | | | Georgia | X | | | | | | | | Hawaii | X | | | | | | | | Idaho | | | | X | | | | | Illinois | | | X | | | | | | Indiana | | | X | | | | | | Iowa | | | X | | | | | | Kansas | | | | | | | | X | Kentucky | | | | X | | | | | Louisiana | | | | X | | | | | - 19 - Table C (cont'd). Period of gestation at which fetal-death reporting is required: Each reporting area, 1992 ______________________________________________________________________________ |All | | |20 |20 |20 | | | |periods| | |weeks |weeks |weeks | | | |of | 16 | 20 |or |or |or |5 | 350 | 500 |gesta- | wks | wks |350 |400 |500 |mos.|grams|grams Area |tion | | |grams |grams |grams | | | ____________________|_______|_____|_____|______|______|______|____|_____|_____ Maine | | | X | | | | | | Maryland | | | 4X | | | | | | Massachusetts | | | | X | | | | | Michigan | | | | | X | | | | Minnesota | | | X | | | | | | Mississippi | | | | X | | | | | Missouri | | | | X | | | | | Montana | | | | | | X | | | Nebraska | | | X | | | | | | Nevada | | | X | | | | | | New Hampshire | | | | X | | | | | New Jersey | | | X | | | | | | New Mexico | | | | | | | | | X New York | | | | | | | | | New York excluding| | | | | | | | | New York City | X | | | | | | | | New York City | X | | | | | | | | North Carolina | | | X | | | | | | North Dakota | | | X | | | | | | Ohio | | | X | | | | | | Oklahoma | | | X | | | | | | Oregon | | | 5X | | | | | | Pennsylvania | | X | | | | | | | Rhode Island | X | | | | | | | | South Carolina | | | | X | | | | | South Dakota | | | | | | | | | X Tennessee | | | | | | | | | 6X Texas | | | X | | | | | | Utah | | | X | | | | | | Vermont | | | 7X | | | | | | Virginia | X | | | | | | | | Washington | | | X | | | | | | West Virginia | | | X | | | | | | Wisconsin | | | | X | | | | | Wyoming | | | X | | | | | | Puerto Rico | | | | | | | X | | Virgin Islands | X | | | | | | | | Guam | | | X | | | | | | _____________________________________________________________________________ 1.If gestational age is unknown, weight of 350 grams or more. 2.Although State law requires the reporting of fetal deaths of all periods of gestation, only data for fetal deaths of 20 weeks of gestation or more are provided to NCHS. - 20 - 3.If weight is unknown, 20 completed weeks of gestation or more. 4.If gestational age is unknown, weight of 500 grams or more. 5.If gestational age is unknown, weight of 400 grams or more, or crown-heel length of 28 centimeters or more. 6.If weight is unknown, 22 completed weeks of gestation or more. 7.If gestational age is unknown, weight of 400 grams or more, 15 ounces or more. Underreporting of fetal deaths is most likely to occur in the earlier part of the required reporting period for each State (37). Thus for States requiring reporting of all periods of gestation, fetal deaths occurring under 20 weeks of gestation are less completely reported; for States requiring reporting of fetal deaths of 20 weeks, fetal deaths occurring at 20-23 weeks are less completely reported. Thus, reporting of fetal deaths at 20-23 weeks of gestation may be more complete for those States that report fetal deaths at all periods of gestation than for others. To maximize the comparability of data by year and by State, most of the tables in section 3 are based on fetal deaths occurring at gestations of 20 weeks or more. These tables also include fetal deaths for which gestation is not stated for those States requiring reporting at 20 weeks of gestation or more only. Beginning with 1969 fetal deaths of not stated gestation were excluded for States requiring reporting of all products of conception except for those with a stated birthweight of 500 grams or more. In 1992 this rule was applied to the following States: Georgia, Hawaii, New York (including New York City), Rhode Island, and Virginia. Each year, there are exceptions to this procedure. Arkansas--Since 1971 Arkansas has been using two reporting forms for fetal deaths: A confidential Spontaneous Abortion form that is not sent to NCHS and a Fetal Death Certificate that is. Because of State changes concerning fetal death registration in 1981 and 1984 (see Technical Appendix from Vital Statistics of the United States, 1990), the comparability of counts of early fetal deaths may be affected. In particular, counts of fetal deaths at 20 to 27 weeks for 1981-83 were not comparable between Arkansas and other reporting areas or with Arkansas data for 1984-92. It is believed that reporting has improved but is still not comparable with data for 1980 and earlier years. Colorado--Although Colorado State law requires reporting fetal deaths of all periods of gestation, beginning in 1989 the State provides to NCHS only data for fetal deaths of 20 weeks of gestation or more. Delaware--Beginning in 1992, Delaware changed its reporting requirements for spontaneous fetal deaths from 20 weeks of gestation or more to 350 grams or more (table C). If weight is unknown, all fetal deaths of 20 weeks of gestation or more should be reported. Maryland--From the counts of frequencies by month, it appears that not all fetal deaths occurring in the first quarter of 1989 were reported. This may account in part for the lower fetal mortality rates for Maryland for 1989 relative to more recent years shown in table 3-5. Montana--Beginning in October 1991, Montana changed its reporting requirements for spontaneous fetal deaths from 20 weeks of gestation or more to 20 weeks of gestation or more or 500 grams (table C). - 21 - New York City--As a result of local efforts to improve reporting, a combined total of 10,470 additional 1990 and 1991 fetal death records were sent from New York City hospitals after the data files had been processed and tabulated. Most of these records are for fetal deaths under 20 weeks of gestation or not-stated gestation. The values in the tables showing data for 1991 may exclude the additional deaths. Revised Report of Fetal Death for 1989--Beginning with data for 1989, new items were added to the U.S. Standard Report of Fetal Death, including Hispanic origin of the mother and father, medical and other risk factors of pregnancy, obstetric procedures, and method of delivery. In addition, questions on complications of labor and/or delivery and congenital anomalies of fetus were changed from an open-ended question to a checkbox format to ensure more complete reporting of information. Interpretation of these data must include evaluation of the item completeness of reporting. The percent "not stated" is one measure of the quality of the data. Completeness of reporting varies among items and States. See table D for the percent of fetal death records on which specified items were not stated. The tabulation of items in the fetal death section is limited to those States whose reporting is sufficiently complete. For fetal deaths before data year 1991, data were published when a State had a response for the item on at least 20 percent of the records. Beginning in data year 1991, tabulations of prenatal care and educational attainment include only those States with a response for that specific item on at least 80 percent of the fetal death records. For the other tables in the fetal death section, item completion is high (table D) and no reporting criterion is used to exclude States. Period of gestation--The period of gestation is the number of completed weeks elapsed between the first day of the last normal menstrual period (LMP) and the date of delivery. The first day of the LMP is used as the initial date because it can be more accurately determined than the date of conception, which usually occurs 2 weeks after LMP. Data on period of gestation are computed from information on "date of delivery" and "date last normal menses began." If "date last normal menses began" is not on the record or if the calculated gestation falls beyond a duration considered biologically plausible, the "Physician's estimate of gestation" is used. To improve data quality, beginning with data for 1989, NCHS instituted a new computer edit to check for consistency between gestation and birthweight (39). Briefly, if LMP gestation is inconsistent with birthweight, and the physician's estimate is consistent, the physician's estimate is used; if both are inconsistent with birthweight but consistent with each other, LMP gestation is used, and birthweight is assigned to unknown. When the period of gestation is reported in months on the report, it is allocated to gestational intervals in weeks as follows: 1 - 3 months to under 16 weeks 4 months to 16 - 19 weeks 5 months to 20 - 23 weeks 6 months to 24 - 27 weeks 7 months to 28 - 31 weeks 8 months to 32 - 35 weeks 9 months to 40 weeks 10 months and over to 43 weeks and over - 22 - Table D. Percent of fetal death records on which specified items were not stated: Each State, 1992 [By place of occurrence. Records include only those with stated or presumed period of gestation of 20 weeks or more] ___________________________________________________________________________ | | | | | Month| Number| | | | | | pre- | of |Hispanic |Length of| |Place | | natal| pre- |origin Area |gestation|Marital| of | Birth- | care | natal |of | 1 |status |delivery| weight | began| visits|mother ______________|_________|_______|________|________|______|_______|_________ Alabama | 0.3 | - | - | 3.7 | 2.6 | 3.4 | - Alaska | - | - | - | 3.6 | - | - | 3.6 Arizona | 3.0 | 0.9 | - | 5.7 | 13.4 | 18.0 | 1.8 Arkansas | 0.4 | 0.4 | - | 4.4 | 10.9 | 13.1 | - California | 10.6 | --- | 0.1 | 1.3 | 7.3 | 8.4 | 1.4 Colorado | - | 2.7 | 0.3 | 9.3 | 13.6 | 14.6 | 8.5 Connecticut | 40.7 | --- | 1.5 | 8.9 | 53.2 | 53.2 | 48.0 Delaware | 7.2 | - | - | 14.5 | 11.6 | 11.6 | 5.8 Dist. of Col. | 10.2 | 11.5 | - | 13.6 | 30.6 | 30.6 | 4.7 Florida | 3.8 | 2.4 | - | 8.1 | 16.7 | 15.7 | 1.3 Georgia | 1.0 | 0.9 | 0.1 | 18.2 | 14.2 | 15.8 | 7.6 Hawaii | - | - | - | 24.4 | 33.9 | 33.9 | 11.0 Idaho | 1.2 | - | - | 12.8 | 4.7 | 7.0 | - Illinois | 3.5 | 5.6 | - | 6.2 | 10.9 | 11.9 | 5.0 Indiana | 0.5 | 1.6 | - | 9.2 | 7.4 | 10.4 | 3.5 Iowa | 1.3 | - | - | 3.8 | 2.9 | 4.2 | 0.8 Kansas | 1.9 | - | - | - | 3.3 | 4.3 | 1.9 Kentucky | 0.8 | 0.8 | - | 1.6 | 4.2 | 6.3 | 0.3 Louisiana | 15.0 | 0.2 | 0.4 | 2.0 | 6.0 | 9.2 | --- Maine | 17.9 | 15.5 | - | 25.0 | 4.8 | 7.1 | 23.8 Maryland | 45.3 | --- | 0.6 | 36.4 | 43.0 | --- | --- Massachusetts | - | 1.2 | - | 1.6 | 3.5 | 3.3 | --- Michigan | 1.1 | --- | - | 2.5 | 7.3 | 13.2 | 12.3 Minnesota | 1.5 | 6.1 | - | 7.8 | 6.3 | 6.6 | 2.2 Mississippi | 1.4 | 1.0 | 0.6 | 3.8 | 15.0 | 19.8 | 0.8 Missouri | 0.8 | 0.2 | - | 5.4 | 11.0 | 8.8 | 1.4 Montana | - | - | 1.4 | 1.4 | - | - | 9.7 Nebraska | 1.7 | 1.7 | - | 8.1 | 0.6 | 0.6 | 4.0 Nevada | 2.2 | --- | 0.7 | 20.6 | 24.3 | 25.0 | 2.9 New Hampshire | - | - | - | 2.6 | 5.1 | 7.7 | --- New Jersey | 6.7 | 3.2 | - | 21.1 | 15.7 | 18.9 | 2.4 New Mexico | 1.0 | 3.8 | - | 10.5 | 6.7 | 8.6 | 8.6 New York State| 2.8 | --- | 0.3 | 31.0 | 14.7 | 19.4 | 13.4 New York City | 2.1 | --- | 0.1 | 20.0 | 24.6 | 21.9 | 22.9 North Carolina| 0.9 | 0.2 | - | 7.4 | 3.2 | 3.6 | - North Dakota | 2.8 | - | - | 9.9 | 5.6 | 4.2 | 2.8 Ohio | 0.9 | 39.0 | - | 8.0 | 8.3 | 11.4 | 2.0 Oklahoma | 47.9 | 1.9 | - | 26.6 | 46.5 | 47.9 | --- Oregon | 0.8 | 0.8 | - | 5.3 | 2.3 | 1.1 | - Pennsylvania | 7.5 | 10.3 | 0.1 | 19.2 | 19.6 | 19.6 | 3.9 - 23 - Table D (cont'd). Percent of fetal death records on which specified items were not stated: Each State, 1992 [By place of occurrence. Records include only those with stated or presumed period of gestation of 20 weeks or more] ___________________________________________________________________________ | | | | | Month| Number| | | | | | pre- | of |Hispanic |Length of| |Place | | natal| pre- |origin Area |gestation|Marital| of | Birth- | care | natal |of | 1 |status |delivery| weight | began| visits|mother ______________|_________|_______|________|________|______|_______|_________ Rhode Island | 2.2 | 80.9 | - | 10.1 | 95.5 | 96.6 | 94.4 South Carolina| 1.1 | 1.2 | - | 3.9 | 7.7 | 7.8 | 3.0 South Dakota | - | - | 3.3 | 3.3 | - | - | - Tennessee | 0.9 | 2.4 | - | 2.6 | 10.6 | 11.0 | 2.6 Texas | 6.0 | --- | 0.1 | 12.5 | 12.9 | 14.4 | 0.2 Utah | 1.9 | 3.0 | - | 8.7 | 11.0 | 12.5 | 1.5 Vermont | - | - | 4.3 | 15.2 | 17.4 | 17.4 | 6.5 Virginia | 1.0 | 1.9 | - | 27.3 | 23.9 | 28.5 | 7.1 Washington | 2.8 | 2.4 | - | 10.7 | 15.9 | 19.1 | 5.9 West Virginia | 1.2 | - | - | 4.7 | 9.5 | 8.9 | 1.2 Wisconsin | 0.2 | 0.2 | - | 0.9 | 1.5 | 2.0 | 0.4 Wyoming | - | - | - | 10.3 | 2.6 | 2.6 | - - 24 - Table D (cont'd). Percent of fetal death records on which specified items were not stated: Each State, 1992 [By place of occurrence. Records include only those with stated or presumed period of gestation of 20 weeks or more] ______________________________________________________________________________ |Mother's| | | |Obste- |Complica- | |educa- |Medical| | | tric |tions of | |tional |risk | | | proce- |labor &/or|Con- Area |attain- |factors|Tobacco|Alcohol| dures |delivery |genital |ment | 2 | use | use | 3 | 4 |anomalies ______________|________|_______|_______|_______|________|__________|__________ Alabama | 3.7 | 2.8 | - | - | 2.9 | 3.2 | 3.6 Alaska | 9.1 | - | 1.8 | 3.6 | - | - | - Arizona | 8.4 | 2.1 | 6.4 | 7.5 | 0.9 | 1.4 | 2.1 Arkansas | 10.5 | 0.4 | 3.3 | 4.0 | 0.4 | 1.8 | 1.8 California | 6.9 | 14.0 | --- | --- | 11.5 | 18.2 | 12.5 Colorado | 19.4 | 13.6 | 21.5 | 22.9 | 11.2 | 13.0 | 15.4 Connecticut | 67.9 | 42.8 | 54.4 | 57.5 | 40.1 | 43.1 | 51.7 Delaware | 8.7 | 7.2 | 13.0 | 11.6 | 7.2 | 8.7 | 10.1 Dist. of Col. | 29.8 | 43.0 | 58.7 | 63.4 | 44.3 | 40.9 | 66.8 Florida | 9.2 | 3.9 | 7.7 | 8.4 | 3.6 | 4.6 | 5.5 Georgia | 28.8 | 7.4 | 6.9 | 7.8 | 2.2 | 2.6 | 4.1 Hawaii | 22.8 | --- | --- | --- | --- | --- | --- Idaho | 4.7 | 3.5 | 3.5 | 8.1 | 2.3 | 1.2 | 1.2 Illinois | 9.9 | 14.6 | 14.7 | 18.5 | 17.8 | 17.4 | 19.8 Indiana | 7.1 | 1.2 | --- | 11.5 | 4.3 | 3.3 | 5.3 Iowa | 2.9 | 0.8 | 0.8 | 1.7 | - | - | 1.7 Kansas | 2.9 | 21.5 | 11.0 | 12.0 | 8.1 | 25.8 | 17.2 Kentucky | 1.8 | 17.3 | 15.0 | 17.6 | 16.5 | 18.4 | 34.4 Louisiana | 6.8 | --- | --- | --- | --- | --- | --- Maine | 26.2 | 14.3 | 19.0 | 26.2 | 13.1 | 19.0 | 25.0 Maryland | 38.0 | --- | --- | --- | --- | --- | --- Massachusetts | 17.5 | --- | --- | --- | --- | --- | --- Michigan | 16.3 | 3.0 | 6.5 | 8.4 | 2.2 | 3.7 | 6.4 Minnesota | 9.0 | 8.8 | 9.5 | 11.2 | 5.4 | 7.3 | 16.1 Mississippi | 16.6 | 2.2 | 5.4 | 5.6 | 1.2 | 1.6 | 3.0 Missouri | 10.8 | 0.6 | 4.4 | 4.8 | 1.4 | 1.0 | 2.4 Montana | 5.6 | 2.8 | 2.8 | 4.2 | - | - | - Nebraska | 3.5 | 0.6 | 2.9 | 4.0 | - | - | 2.9 Nevada | 5.9 | 16.2 | 22.8 | 25.7 | 15.4 | 21.3 | 22.8 New Hampshire | 11.5 | - | - | - | - | - | - New Jersey | 18.6 | 6.7 | 10.6 | 11.9 | 6.0 | 9.8 | 9.4 New Mexico | 40.0 | 1.0 | 4.8 | 5.7 | - | 1.0 | --- New York State| 25.6 | 20.9 | --- | --- | 9.4 | 21.1 | --- New York City | 42.0 | 6.0 | --- | --- | 4.4 | 10.7 | --- North Carolina| 3.5 | 0.4 | 2.4 | 2.6 | 0.8 | 0.5 | 1.1 North Dakota | 4.2 | 4.2 | 15.5 | 16.9 | 8.5 | 5.6 | 8.5 Ohio | 12.0 | 4.1 | 9.7 | 11.1 | 3.5 | 4.5 | 6.5 Oklahoma | 37.1 | --- | --- | --- | --- | --- | --- Oregon | 7.9 | 2.6 | 3.0 | 3.0 | 0.4 | - | 1.1 Pennsylvania | 16.3 | 9.3 | 15.2 | 16.8 | 6.9 | 9.1 | 20.3 - 25 - Table D (cont'd). Percent of fetal death records on which specified items were not stated: Each State, 1992 [By place of occurrence. Records include only those with stated or presumed period of gestation of 20 weeks or more] ______________________________________________________________________________ |Mother's| | | |Obste- |Complica- | |educa- |Medical| | | tric |tions of | |tional |risk | | | proce- |labor &/or|Con- Area |attain- |factors|Tobacco|Alcohol| dures |delivery |genital |ment | 2 | use | use | 3 | 4 |anomalies ______________|________|_______|_______|_______|________|__________|__________ Rhode Island | 95.5 | 60.7 | 76.4 | 76.4 | 57.3 | 60.7 | 74.2 South Carolina| 12.8 | 3.2 | 10.9 | 11.4 | 5.2 | 2.0 | 4.3 South Dakota | 1.6 | - | --- | --- | - | 1.6 | - Tennessee | 8.2 | 4.1 | 6.3 | 6.7 | 4.3 | 5.4 | 9.7 Texas | 11.4 | 52.3 | 51.0 | 52.2 | 45.7 | 48.0 | 48.4 Utah | 9.9 | 6.5 | 9.1 | 9.1 | 4.2 | 6.5 | 14.4 Vermont | 4.3 | - | 8.7 | 21.7 | - | - | 8.7 Virginia | 34.7 | 23.3 | 29.1 | 32.0 | 22.4 | 26.1 | 33.5 Washington | 22.4 | 17.6 | 15.0 | 30.9 | 19.6 | 20.0 | 31.1 West Virginia | 12.4 | - | 16.6 | 20.1 | - | - | - Wisconsin | 2.2 | 0.4 | 0.9 | 0.9 | 1.1 | 0.7 | 0.9 Wyoming | - | - | 2.6 | 2.6 | - | - | - - Quantity zero. ---Data not available. 1 California, Louisiana, Maryland, and Oklahoma report date last normal menses but do not report clinical estimate of gestation. 2 Kansas and South Dakota do not report Rh sensitization; New York State does not report genital herpes, hydramnios/oligohydramnios, hemoglobinopathy, incompetent cervix, previous infant 4000 grams or more, and previous preterm or small for gestational age infant; Texas does not report genital herpes and uterine bleeding. 3 Illinois does not report ultrasound. 4 New York State does not report cephalopelvic disproportion; Texas does not report cephalopelvic disproportion, anesthetic complications, and fetal distress. - 26 - All areas reported LMP in 1992, and all areas except California, Louisiana, Maryland, and Oklahoma reported physician's estimate of gestation. Birthweight--Most of the 55 registration areas do not specify how weight should be given, that is, in pounds and ounces or in grams. In the tabulation and presentation of birthweight data, the metric system (grams) has been used to facilitate comparison with other data published in the United States and internationally. Birthweight specified in pounds and ounces is assigned the equivalent of the gram intervals, as follows: Less than 350 grams = 0 lb 12 oz or less 350-499 grams = 0 lb 13 oz - 1 lb 1 oz 500 - 999 grams = 1 lb 2 oz - 2 lb 3 oz 1,000 - 1,499 grams = 2 lb 4 oz - 3 lb 4 oz 1,500 - 1,999 grams = 3 lb 5 oz - 4 lb 6 oz 2,000 - 2,499 grams = 4 lb 7 oz - 5 lb 8 oz 2,500 - 2,999 grams = 5 lb 9 oz - 6 lb 9 oz 3,000 - 3,499 grams = 6 lb 10 oz - 7 lb 11 oz 3,500 - 3,999 grams = 7 lb 12 oz - 8 lb 13 oz 4,000 - 4,499 grams = 8 lb 14 oz - 9 lb 14 oz 4,500 - 4,999 grams = 9 lb 15 oz - 11 lb 0 oz 5,000 grams or more = 11 lb 1 oz or more With the introduction of ICD-9, the birthweight classification intervals for perinatal mortality statistics were shifted downward by 1 gram as shown above. Previously, the intervals were, for example, 1,001-1,500, 1,501-2,000, and so forth. Beginning in 1989 NCHS instituted a consistency check between birthweight and gestation; see previous section on gestation. Race--Beginning with data for 1989, NCHS changed the method of tabulating fetal death, perinatal, and live birth data by race from race of child to race of mother. When the race of the mother is unknown, the mother is assigned the father's race; when information for both parents is missing, the race of the mother is assigned to the specific race of the mother of the preceding record with known race. The change in tabulation of race has resulted in a discontinuity in fetal mortality rates by race for data years 1989-92 relative to previous years; see "Change in tabulation of race data for live births and fetal deaths," under "Infant deaths" or the series report, "Effect on Mortality Rates of the 1989 Change in Tabulating Race" (24). Hispanic origin of mother--Fetal mortality data for the Hispanic-origin population are based on fetal deaths to mothers of Hispanic origin who were residents of those States and the District of Columbia that included items on the report of fetal death to identify Hispanic or ethnic origin of mother. Data for 1992 were obtained from 45 States and the District of Columbia; areas not supplying data were Louisiana, Maryland, Massachusetts, New Hampshire, and Oklahoma. - 27 - For 1992 fetal and perinatal mortality data in tables 3-18 and 4-6 are for 45 States and the District of Columbia and tables 3-19 and 4-7 are for 41 States, New York (excluding New York City) and the District of Columbia that had an item on Hispanic or ethnic origin on the death certificate, birth certificate, and report of fetal death and whose data for all three files were at least 80 percent complete on a place-of-occurrence basis and considered to be sufficiently comparable to be used for analysis. The States included are Alabama, Alaska, Arizona, Arkansas, California, Colorado, District of Columbia, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Jersey, New Mexico, New York (excluding New York City), North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming. The 41 States, New York (excluding New York City), and the District of Columbia for which fetal and perinatal data by Hispanic origin are shown accounted for about 87 percent of the Hispanic population in 1990, including 99 percent of the Mexican population, 51 percent of the Puerto Rican population, 91 percent of the Cuban population, and 76 percent of the "Other Hispanic" population (13). Accordingly, caution should be exercised in generalizing mortality patterns from the reporting area to the Hispanic- origin population (especially Puerto Ricans) of the entire United States. (See also "Hispanic origin" under "Classification of data.") Total-birth order--Total-birth order refers to the sum of live births and other terminations (including spontaneous fetal deaths and induced terminations of pregnancy) a woman has had, including the fetal death being recorded. For example, if a woman has given birth to two live babies and to one born dead, the next fetal death to occur is counted as number four in total-birth order. Beginning with implementation of the 1989 revision of the U.S. Standard Report of Fetal Death, total-birth order is calculated from three items on pregnancy history: Number of previous live births now living; number of previous live births now dead; and number of other terminations (spontaneous and induced at anytime after conception). For prior years, total-birth order was calculated from four items, see the Technical Appendix from Vital Statistics of the United States 1988. Although all registration areas use the two standard items pertaining to number of previous live births, registration areas phrase the item pertaining to other terminations of pregnancy differently. Total-birth order for all areas is calculated from the sum of available information. Thus, information on total-birth order may not be completely comparable among the registration areas. In addition, there may be substantial underreporting of other terminations of pregnancy on the fetal death report. Marital status--Table 3-3 shows fetal deaths and fetal mortality rates by mother's marital status. The following States were excluded from this table because their reports of fetal death did not include an item on marital status: California, Connecticut, Maryland, Michigan, Nevada, New York (including New York City), and Texas. Because live births comprise the denominator of the rate, marital status must be reported for mothers of live births. Marital status of the mother of the live birth is inferred for States that did not report it on the birth certificate. - 28 - Beginning with data for 1989, fetal death reports with marital status not stated are shown as not stated in frequencies, but are proportionally distributed for rate computations into either the married or unmarried categories according to the percent of fetal death reports with stated marital status that fall into each category for the reporting States. Before 1989 fetal death reports with not-stated marital status were assigned to the married category. Because of this change, fetal death frequencies and rates by marital status for 1989-92 are not strictly comparable with those for previous years. No quantitative data exist on the characteristics of unmarried women who do not report, misreport their marital status, or fail to register fetal deaths. Underreporting may be greater for the unmarried group than for the married group. Age of mother--Beginning with data for 1989, the U.S. Standard Report of Fetal Death asks for the mother's date of birth. Age of mother is computed from the mother's date of birth and the date of the termination of the pregnancy. For those States whose certificates do not contain an item for the mother's date of birth, reported age of the mother (in years) is used. The age of the mother is edited in NCHS for upper and lower limits. When mothers are reported to be under 10 years of age or 50 years of age and over, the age of the mother is considered not stated and is assigned as follows: Age on all fetal-death records with age of mother not stated is assigned according to the age appearing on the record previously processed for a mother of identical race and having the same total-birth order (total of live births and other terminations). Sex of fetus--Beginning with data for 1989, for all fetal deaths of 20 weeks of gestation or more, not-stated sex of fetus is assigned the sex of the fetus from the previous record. Before 1989 no such assignment was made. Plurality--All registration areas except Louisiana report the plurality of the fetus. Although Louisiana has not reported this item for many years, before 1989, data for Louisiana were erroneously converted to a plurality of 1 (single birth) and included in United States totals. Beginning with 1989 data, Louisiana is excluded from tables reporting plurality of the fetus. For reporting areas, not-stated plurality of the fetus is assigned to single births. Perinatal mortality Perinatal definitions--Beginning with data year 1979, perinatal mortality data for the United States and each State have been published in section 4. WHO recommends in ICD-9, "national perinatal statistics should include all fetuses and infants delivered weighing at least 500 grams (or when birthweight is unavailable, the corresponding gestational age (22 weeks) or body length (25 cm crown-heel)), whether alive or dead...." It further recommends, "countries should present, solely for international comparisons, 'standard perinatal statistics' in which both the numerator and denominator of all rates are restricted to fetuses and infants weighing 1,000 grams or more (or, where birthweight is - 29 - unavailable, the corresponding gestational age (28 weeks) or body length (35 cm crown-heel))." Because birthweight and gestational age are not reported on the death certificate in the United States, NCHS was unable to adopt these definitions. Three definitions of perinatal mortality are used by NCHS: Perinatal Definition I, generally used for international comparisons, which includes fetal deaths of 28 weeks of gestation or more and infant deaths under 7 days; Perinatal Definition II, which includes fetal deaths of 20 weeks of gestation or more and infant deaths under 28 days; and Perinatal Definition III, which includes fetal deaths of 20 weeks of gestation or more and infant deaths under 7 days. Variations in fetal death reporting requirements and practices have implications for comparing perinatal rates among States. Because reporting is generally sporadic near the lower limit of the reporting requirement, States that require reporting of all products of pregnancy, regardless of gestation, are likely to have more complete reporting of fetal deaths at 20 weeks or more than those States that do not. The larger number of fetal deaths reported for these "all periods" States may result in higher perinatal mortality rates than those rates reported for States whose reporting is less complete. Accordingly, reporting completeness may account, in part, for differences among the State perinatal rates, particularly differences for Definitions II and III, which use data for fetal deaths at 20-27 weeks. Not stated--Fetal deaths with gestational age not stated are presumed to be of 20 weeks of gestation or more if the State requires reporting of all fetal deaths at a gestational age of 20 weeks or more or the fetus weighed 500 grams or more in those States requiring reporting of all fetal deaths, regardless of gestational age. For Definition I, fetal deaths at a gestation not stated but presumed to have been of 20 weeks or more are allocated to the category 28 weeks or more, according to the proportion of fetal deaths with stated gestational age that falls into that category. For Definitions II and III, fetal deaths at a presumed gestation of 20 weeks or more are included with those at a stated gestation of 20 weeks or more. The allocation of not-stated gestational age for fetal deaths is made individually for each State, for metropolitan and nonmetropolitan areas, and separately for the entire United States. Accordingly, the sum of perinatal deaths for the areas according to Definition I may not equal the total number of perinatal deaths for the United States. Race--Beginning with the 1989 data year, NCHS has changed the method of tabulating fetal death and live birth data by race from race of child to race of mother. This has resulted in a discontinuity in perinatal mortality rates by race between 1989 and previous years; see "Change in tabulation of race data for live births and fetal deaths" under "Infant deaths." Hispanic origin--See "Hispanic origin of mother" under "Fetal deaths." Occupation and Industry Deaths by occupation and industry are included on this 1992 cd-rom. These data were included for the first time for 1985. These data were obtained from the following items that appear on the U.S. Standard - 30 - Certificate of Death:. (Item 14a) USUAL OCCUPATION (Give kind of work done during most of working life, even if retired). (Item 14b) KIND OF BUSINESS OR INDUSTRY The occupation and industry mortality data were provided to NCHS by the following 21 reporting States: Colorado North Carolina Georgia Ohio Idaho Oklahoma Indiana Rhode Island Kansas South Carolina Kentucky Utah Maine Vermont Nevada Washington New Hampshire West Virginia New Jersey Wisconsin New Mexico The occupation and industry titles corresponding to the 3-digit occupa- tion codes and the 3-digit industry codes are shown in a Bureau of the Census publication. In addition to the codes shown in the Census publication, the following special codes were created: Occupation Industry 905 Military 942 Military 913 Retired 951 Retired 914 Homemaker 961 Homemaker, student, unemployed 915 Student volunteer 916 Volunteer 990 Blank,Unknown,NA 917 Unemployed, never worked, disabled 999 Blank, Unknown, NA Special summary occupation and industry lists were created and are shown elsewhere in this documentation. Also, a special cause-of-death list was created including possible occupationally-related causes of death. This list is the List of 52 selected causes shown elsewhere in this documentation. - 31 -