Death certificates are a potential source of sociodemographic data for decedents in epidemiologic research. However, because this information is provided by the next-of-kin or other proxies, there are concerns about validity. Our objective was to assess the agreement of job titles and occupational categories derived from death certificates with that self-reported in mid and later life.
Occupation was abstracted from 431 death certificates from North Carolina Atherosclerosis Risk in Communities Study participants who died between 1987 and 2001. Occupations were coded according to 1980 Bureau of Census job titles and then grouped into six 1980 census occupational categories. This information was compared with the self-reported occupation at midlife as reported at the baseline examination (1987├óÔé¼ÔÇ£89). We calculated percent agreement using standard methods. Chance-adjusted agreement was assessed by kappa coefficients, with 95% confidence intervals.
Agreement between death certificate and self-reported job titles was poor (32%), while 67% of occupational categories matched the two sources. Kappa coefficients ranged from 0.53 for technical/sales/administrative jobs to 0.68 for homemakers. Agreement was lower, albeit nonsignificant, for women (kappa = 0.54, 95% Confidence Interval, CI = 0.44├óÔé¼ÔÇ£0.63) than men (kappa = 0.62, 95% CI = 0.54├óÔé¼ÔÇ£0.69) and for African-Americans (kappa = 0.47, 95% CI = 0.34├óÔé¼ÔÇ£0.61) than whites (kappa = 0.63, 95% CI = 0.57├óÔé¼ÔÇ£0.69) but varied only slightly by educational attainment.
While agreement between self- and death certificate reported job titles was poor, agreement between occupational categories was good. This suggests that while death certificates may not be a suitable source of occupational data where classification into specific job titles is essential, in the absence of other data, it is a reasonable source for constructing measures such as occupational SES that are based on grouped occupational data.
Data from death certificates are used to monitor age, race and gender variations in mortality in the United States, US 1,2. While sociodemographic information on death certificates is obtained from next of kin or other proxies, studies have indicated high validity of such information when compared with other official documents 3. In the late 1980s the National Center for Health Statistics implemented guidelines to standardize data collected on death certificates across the US 4. As a result information related to employment (job title and industry) and educational attainment is available on certificates of death, which facilitates the monitoring of socioeconomic related trends and rates of mortality across the US In addition, information of employment and education on death certificates is useful in epidemiologic studies when SES is not available from other sources. However, the comparability of such data to that from self-report is not well established.
Studies assessing the agreement of educational attainment from death certificate with that obtained by self- report have reported that death certificates record higher 5,6 and lower 7 levels of education than that obtained by self-report. However, there is high agreement between death certificate-derived educational attainment and that obtained from self-report when data are grouped into ordered categories 5-7. To our knowledge, the comparability of death certificate-based occupational measures of SES to those obtained by self-report has not been assessed. The purpose of the current study was to compare the agreement of death certificate-based job titles and associated occupational categories with those self-reported in midlife in the Atherosclerosis Risk in Communities (ARIC) Study. We examined agreement overall, and by race, gender, age and educational attainment.
Details of the design and procedures of the ARIC Study are presented elsewhere 8. Briefly, at inception (1987├óÔé¼ÔÇ£1989), a biracial cohort of 15,792 middle-aged men and women was sampled from four communities in the United States (Washington County, MD; Forsyth County, NC; north western suburbs of Minneapolis, MN; and Jackson, MS). Institutional review board approval was obtained by each participating field center and the coordinating center. Written informed consent was obtained from each study participant.
- Ayala C, Croft JB, Greenlund KJ, Keenan NL, Donehoo RS, Malarcher AM, Mensah GA: Sex differences in US mortality rates for stroke and stroke subtypes by race/ethnicity and age, 1995├óÔé¼ÔÇ£1998. Stroke 2002, 33(5):1197-201.
- Caveney AF, Smith MA, Morgenstern LB, Lisabeth LD: Use of death certificates to study ethnic-specific mortality. Public Health Report 2006, 121(3):275-81.
- Houghton F: Misclassification of racial/ethnic minority deaths: the final colonization. American Journal of Public Health 2002, 92(9):1386.
- National Center for Health Statistics: Guidelines for reporting occupation and industry on death certificates. Hyattsville (MD): Department of Health and Human Services (US), Public Health Service; 1988.
- Shai D, Rosenwaike I: Errors in reporting education on the death certificate: some findings for older male decedents from New York State and Utah. American Journal of Epidemiology 1989, 130:188-192.
- Sorlie PD, Johnson NJ: Validity of education information on the death certificate. Epidemiology 1996, 7(4):437-9.
- Rosamond WD, Tyroler HA, Chambless LE, Folsom AR, Cooper L, Conwill D: Educational achievement recorded on certificates of death compared with self-report. Epidemiology 1997, 8(2):202-4.
- The ARIC Investigators: The Atherosclerosis Risk in Communities (ARIC) study: design and objectives. American Journal of Epidemiology 1989, 129:687-702.
- Census Bureau: 1980 Census of Population Classified Index of Industries and Occupations. Washington, DC.: US Government Printing Office; 1980.
- 1980 Census of the Population: Alphabetical Index of Industries and Occupations. Washington, D.C.: US Government Printing Office; 1992.
- Kelsey JL, Thompson WD, Evans AS: Methods in Observational Epidemiology. New York: Oxford University Press; 1986:287.
- Fleiss JL: Statistical methods for rates and proportions. New York: John Wiley and Sons; 1981:140-7.
- SAS Institute, Inc: SAS/STAT user's guide, version 8.2. Cary, NC. 2001.
- Landis JR, Koch GG: The measurement of observer agreement for categorical data. In Biometrics. Volume 33. International Biometric Society; 1977:159-174.
- Steenland K, Beaumont J: The accuracy of occupation and industry data on death certificates. Journal of occupational Medicine 1984, 26(4):288-96.
- Turner DW, Schumacher MC, West DW: Comparison of occupational interview data to death certificate data in Utah. American Journal of Industrial Medicine 1987, 12:145-151.
- Olsen GW, Brondum J, Bodner KM, Kravat BA, Mandel JS, Mandel JH, Bond GG: Occupation and industry on death certificates of long-term chemical workers concordance with work history records. American Journal of Industrial Medicine 1990, 17(4):465-81.
- McLaughlin JK, Mehl ES: A comparison of occupational data from death certificates and interviews. American Journal of Industrial Medicine 1991, 20:335-342.
- Andrews KW, Savitz DA: Accuracy of industry and occupation on death certificates of electric utility workers: implications for epidemiologic studies of magnetic fields and cancer. Bioelectromagnetics 1999, 20:512-518.
- Kim HR, Khang YH: Reliability of education and occupational class: a comparison of health survey and death certificate data. Journal of Preventive Medicine and Public Health 2005, 38(4):443-8.