The accuracy of occupation and industry data on death certificates

To assess the accuracy of occupation and industry data on death certificates, we compared the known occupation and industry of 3,789 individuals with information on their death certificates. All individuals were members of the National Institute for Occupational Safety and Health cohort studies and their occupation and industry were known from personnel or union records. We focused our analysis on 2,198 long-term workers who had 10 or more years of work experience (average, 18 years). Our principal finding was that for the long-term workers in our sample, the probability of the known occupation being listed on their death certificates was 64.7% (SE = 1.1) (for white workers this figure was 73.5% (SE = 1.2). Furthermore, for the long-term workers the probability of the plant or industry being named on their death certificates was 70.1% (SE = 1.2). Women and non-whites had lower matching rates. For women the probability of a matched listing was 45.1% for occupation and 60.4% for industry. For nonwhites, it was only 30.1% for occupation and 49.2% for industry. Our results for white long-term workers generally agree with the results of previous investigators who have used different methods.     

Agreement of occupation and industry data on Rhode Island death certificates with two alternative sources of information

There is increasing interest in documenting the putative health effects of occupational hazards, prompting Federal and State efforts that rely primarily on occupational information obtained from the death certificate. Previous studies have assessed the agreement of occupational data on death certificates with actual lifetime employment by using current employment data from census records for comparisons. Such analyses have largely been confined to males. We compared lifetime occupational information obtained from a panel survey for both sexes with death certificate data for 446 deceased panel members. After adjusting for inadequate information, the occupation recorded on the death certificates of the men agreed with the occupation recorded in the survey 66 percent of the time. The comparable percentage for the industry where the deceased had been employed was 78 percent. Among the women's records, agreement on occupation was 65 percent, and on industry, 69 percent. Using another sample of death certificates, comparisons of the information for 322 decedents with city directory data produced similar results. The higher level of agreement for women was due in part to the large number who were reported as "housewives." In a separate analysis, the agreement rate for nonhousewives declined. Suggestions for improvements in the recording of occupational data and the constraints imposed by the use of death certificate data in occupational epidemiology are presented.     

A comparison of occupational data from death certificates and interviews

A comparison was made of the occupational data reported on the death certificates of 586 men with their employment history obtained by interviews. Agreement was assessed for 19 occupational and 14 industrial categories of usual employment, with the highest levels of concordance (greater than or equal to 80%) found for agricultural, medical, and public administration activities. Between the two sources of information, there was overall agreement of 56% for usual occupation and 51% for usual industry of employment. Concordance was highest among the 68 self-respondents (usual occupation 66%; usual industry 53%). Among the 518 surrogates, spousal agreement was highest (58% for occupation and 51% for industry). For other surrogate types, agreement was 49% for both industry and occupation. Agreement varied by duration of employment and by level of education, with concordance tending to increase as length of employment and educational attainment rose. These relationships remained when examined by respondent type. Evaluation of agreement levels by age and other study subject characteristics showed little effect on concordance. Review of verbatim data from the interviews and death certificates revealed that most disagreements could be attributed to coding problems caused by vague or misleading information on the death certificates, although some disconcordance was due to uncodable and missing information in the interview history. Based on results from this and prior studies, the value of occupational data derived from death certificates in epidemiologic studies may be limited, although the addition of explicit instructions on the death certificate itself may aid in providing more useful and complete information for usual employment.     

An assessment of occupation and industry data from death certificates and hospital medical records for population-based cancer surveillance

This study analyzed 30,194 incident cases and 4,301 death certificates for completeness of occupational reporting. Analysis of data accuracy was based upon a comparison of more than 2,000 death certificates with incident abstracts and 352 death certificates with interview data. Death certificates had a higher proportion with occupation (94.3%) and industry (93.4%) reported than did incident abstracts of hospital medical records (39.0% and 63.5%, respectively). Compared with occupational history data obtained by interview, 76.1% of the death certificates were exact matches for usual occupation and industry.     

Validity of information on occupation and principal cause on death certificates in Botucatu, Sao Paulo

The aim of this paper was to evaluate the accuracy of data on death certificates for occupation and main cause of death. Measure of agreement was assessed comparing data from death certificates with those from both medical records and next-of-kin interviews, analyzing information for 552 residents of Botucatu, Southeast Brazil, who died in 1997. Kappa coefficients of 0.31 (95% C.I. 0. 29-0.34) and 0.76 (95% C.I. 0.75-0.76) were obtained for data on occupation and main cause of death, coded by a Brazilian two-digit classification and the three-digit ICD-10 classification, respectively. One can conclude that, although quality of the main cause of death is acceptable for pilot studies, data on occupation taken only from death certificates is not accurate enough to be used in epidemiological research.     

The accuracy of industry data from death certificates for workplace homicide victims.

This study compared death certificate data on usual industry for workplace homicide victims in five urban Texas counties, with medical examiners' data on the industries where victims were working when injured. The overall positive predictive value of the death certificate data was 72 per cent. Death certificate data on usual industry underestimated the number of victims working in high-risk industries when injured, partly because of victims whose usual industry was recorded as student, housewife, or military personnel.     

Occupational information on death certificates: a survey of state practices.

A national survey was conducted in 1979 to determine the extent to which state and local vital registration offices coded and stored occupational information reported on death certificates. This survey found that 11 states routinely code occupation, seven routinely code industry, and six have coded occupation and/or industry on a limited basis. State and federal cooperation is needed to facilitate increased use of mortality data for environmental and occupational health research.     

Identification of cases of sudden infant death syndrome from death certificates.

A method is proposed for identification of cases of sudden infant death syndrome (SIDS) from information available on death certificates. Deaths at ages between 7 days and 2 years, referred to a coroner, having certain specified causes of death codes, identified 160 of 169 cases of SIDS confirmed as such by a pathologist. The sensitivity of the method was 94% and the specificity was 97%.     

Comparison of death certificate occupation and industry data with lifetime occupational histories obtained by interview: variations in the accuracy of death certificate entries

This study compares usual and recent occupation and industry data from lifetime work histories obtained by interview with death certificate entries for occupation and industry for 2,435 persons diagnosed with cancer. Match rates are calculated as the percent of death certificate occupation and industry entries that were confirmed by interview data and are compared for exact 3-digit 1980 U.S. Census Bureau occupation and industry codes and for groups of these codes. The overall match rate for individual usual occupation codes was 47.9% and for exact usual industry codes it was 61.8%. Significant differences between the interview data for usual occupation or industry and the death certificate entry were observed by race and gender, marital status, number of years worked, and occupation and industry groups and by age for industry. Misclassification or overreporting of occupation and industry data on the death certificate ranged from 30 to 50% in this study. Our results suggest that the utility of death certificate data for investigations into the occupational risk factors for cancer may be quite limited.     

A dental x-ray validation study. Comparison of information from patient interviews and dental charts

Information was collected from dentists of a subset of participants in a case-control interview study conducted in Los Angeles County, California, in August 1980-August 1981 to evaluate the relationship of dental x-rays to tumors of the parotid gland. Complete dental charts were available from 142 dentists of 84 cases and from 130 dentists of 79 controls. Analysis of data from these interview-chart comparisons indicates that recall appears to be unbiased since the measures of agreement between interview and dental chart data are similar for cases and controls. The authors further conclude that interview data alone may be used for case-control comparisons of dental x-ray exposure and would, because of unbiased misclassification, tend to underestimate the relative risks.     

Analysis of unlinked infant death certificates from the NIMS project

The National Infant Mortality Surveillance (NIMS) project used linked birth and infant death certificates to calculate birth weight-specific infant mortality risks for the 1980 U.S. birth cohort. Record linkage depends on complete registration of vital events, interstate exchange of vital records, accurate information on certificates, and a comprehensive linkage system. States reported 2,604 unlinked infant death certificates for 1980, ranging from 0 to 397 per State. Age at death for these infants ranged from 1 minute to 11 months. More than 41 percent of the unlinked death certificates were for postneonates, compared with 32.5 percent found in the cohort's total infant death experience. Only 38.2 percent of the unlinked infant death certificates showed strictly intrastate events (birth and death occurrence, and residence at death all in one State), compared with 92.9 percent in the cohort's total infant death experience. Estimates of the percentage successfully linked by State ranged from 86.0 to 100.0. After adjusting for the certainly unlinked infant death certificates, nine States' infant mortality risks increased by more than 0.2 per 1,000 live births. Improvements are needed both within and between States to ensure more complete birth and infant death certificate linkage.     

Occupation and industry on death certificates of long-term chemical workers: concordance with work history records

This study evaluated the concordance between occupation and industry listed on death certificates with actual work history information for a group (n = 5,882) of long-term (10 years or more) workers at a chemical company. Match rates were calculated as the percent of death certificate occupation and company entries that were confirmed by work history data using 3-digit 1980 U.S. Census Bureau group codes. The concordance rate for industry differed by employment status at death: employed, 94.9%; inactive, 30.8%; and retired, 91.1%. Concordance on occupation was analyzed for employed (n = 467) and retired (n = 932) subjects who had computerized work histories (randomly done prior to the study) and who had matched on the company on the death certificate. Concordance ranged from 0 to 50% for the first job, to 50 to 70% for the last job, longest job, and longest job in the last 10 years of company employment. The most consistent predictor of concordance was job duration. Misclassification was reviewed by occupational category. Results from this and other investigations lead to the inevitable conclusion that usual occupation data from death certificates are grossly inadequate for studies of occupational risks.     

Conditions other than underlying cause of death listed on death certificates provide additional useful information for epidemiologic research

Conditions other than underlying cause of death listed on death certificates may provide useful information for epidemiologic research. We explored this possibility for any mention of diabetes, renal diseases, and pneumonia-influenza-bronchitis on death certificates from the Chicago Western Electric Study. When we used any mention, sufficient numbers of deaths for analyses of risk factor associations with diabetes (N = 47), renal diseases (N = 25), and pneumonia-influenza-bronchitis (N = 59) were available; analyses for these risk factors were not possible using underlying cause of death alone (N = 3, 6, and 16, respectively). Using Cox regression, we observed positive associations of age, systolic blood pressure, serum cholesterol, body mass index, and cigarettes smoked per day with any mention of diabetes or renal disease. Age, systolic blood pressure, and cigarettes smoked per day were positively related to any mention of pneumonia-influenza-bronchitis; serum cholesterol and body mass index were inversely related to this endpoint. Whether we identified cardiovascular disease deaths using underlying cause, other mention, or any mention, the relations of established major risk factors with 25-year mortality were similar.     

Availability and quality of industry and occupation information in the Massachusetts Cancer Registry.

BACKGROUND: Industry and occupation (I/O) data from state cancer registries can be useful in generating and evaluating hypotheses about occupational cancer risks. The quality of these data is uncertain. METHODS: We reviewed medical records on 1,020 cases from the Massachusetts Cancer Registry (MCR). We compared the presence and detail of I/O data from this dedicated record review (DRR) with routine reporting to the MCR in order to evaluate the potential to increase the availability of I/O data. RESULTS: Compared to routine reporting, the DRR increased the percentage of codable I/O data from 63.6 to 80.4%. The DRR also provided more detail in existing codes in 15.4% of cases. Other sections of the medical record in addition to the face sheet and sections of the record from the period before cancer diagnosis were important sources of additional information. Duration and timing of the corresponding I/O information were rarely recorded. CONCLUSIONS: The nearly one-third (32%) of records that had some improvement in I/O information with a dedicated review indicates considerable opportunity to improve the utility of this resource.     

The recording of demographic information on death certificates: a national survey of funeral directors

OBJECTIVE: The authors sought to ascertain the methods used by funeral directors to determine the demographic information recorded on death certificates. METHODS: Standardized questionnaires were administered to funeral directors in five urban locations in the U.S. In addition, personnel on four Indian reservations were interviewed. Study sites were selected for diverse racial/ethnic populations and variability in recording practices; funeral homes were selected by stratified random sampling. RESULTS: Fifty-two percent of responding funeral directors reported receiving no formal training in death certification. Seventy-nine percent of respondents reported finding certain demographic items difficult to complete--26% first specified race as the problematic item, and 25% first specified education. The decedent's race was "sometimes" or "often" determined through personal knowledge of the family by 58% of respondents; 43% reported "sometimes" or "often" determining race by observation. Only three respondents reported that occupation was a problematic item. CONCLUSIONS: The authors recommend that the importance of demographic data and the instructions for data collection be clarified for funeral directors, that standard data collection worksheets be developed, and that training videos be developed.