Underascertainment of deaths using the social-security administration death master file.
Am J Epidemiol 1995 Jun; 141(11)(Suppl):S58
In 1988 the Social Security Administration (SSA) began providing access to data on deceased individuals in the SSA Death Master File. Prior to that date, different and more complete data on vital status were provided to researchers. Completeness of the SSA Death Master File was examined by comparing the number of recorded deaths with those in the U.S. Vital Statistics records and by searching the SSA Death Master File for known decedents from seven cohorts which were followed for vital status prior to the change in the SSA procedures for providing death information. These data show that the SSA Death Master File missed 46% of U.S. deaths since 1940 and 95% of U.S. deaths from 1940-1960. In the cohort studies, the SSA Death Master File missed 25% of the deaths known to us from either the National Death Index (NDI) or SSA record searches prior to 1988. The greatest underascertainment occurred in the earlier decades. After restricting deaths to those determined from SSA Death Master File and the National Death Index, the two most commonly used sources of death information by U.S. researchers, re-analysis of two cohorts resulted in 20-35% decreases in both standardized mortality ratios (SMRs) and dose-response trends. The current SSA Death Master File is inadequate for vital status determination. This under-ascertainment of deaths will affect primarily cohorts recently assembled in which a substantial number of deaths occurred prior to the availability of NDI data in 1979. In studies in which exposure increases mortality, the effect of exposure may be missed or underestimated due to this underascertainment.
Epidemiology; Exposure-assessment; Mortality-data; Mortality-rates; Mortality-surveys; Recording-systems; Risk-factors; Statistical-analysis; Workplace-studies
National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, DSHEFS, 4676 Columbia Parkway, Cincinnati, OH 45226
American Journal of Epidemiology. Abstracts of the 28th Annual Meeting of the Society for Epidemiologic Research, Snowbird, Utah, June 21-24, 1995