Longitudinal studies based on vital registration records

Abstract

We describe here the increased use of routine vital event and census records to construct national follow-up and longitudinal studies. The strengths and weaknesses of these studies are discussed and examples given of their use in research into relationships between employment and mortality and socio-economic differences in mortality.

PIP: The nature of, the justification for, and the limitation of studies linking vital statistics' records of birth, death, and marriage registration with individual census records are discussed. Studies linking death records with census data have been conducted in the 1970s in England and Wales and France with sample data and in Denmark, Finland, and Norway with full counts. In the US, this was accomplished in the 1960s. This approach, when linked to successive censuses, is a longitudinal record linkage study, which has been conducted in England and Wales by the Office of Population Censuses and Surveys (OPCS). The reasons for conducting such studies is the elimination of the numerator/denominator bias, the expansion of information not possible to include the vital record, the possibility of showing the time factors, and the possibility of examining processes of change. The limitations are cost, size, time, analytic skills and understanding, and data quality. The OPCS Longitudinal Study is used to illustrate the reasons for conducting such studies and the limitations. OPCS was used to examine mortality differentials due to occupational differences for men and women. The results confirmed the census patterns of differences, and showed differences in mortality after retirement age based on occupation. Cause of death was not possible because of the small numbers. The longitudinal study has been useful in the analysis of unemployment and mortality: cause-specific relationships were evidenced; the confounding effects of socioeconomic status were assessed; the argument for reverse causation could be counteracted; the effects on other members of the unemployed men's household could be examined; and periods of high and low unemployment could be investigated. Intergenerational links and downward social mobility from changing economic circumstances are also possible to examine. Clear recognition has been given to studies of socioeconomic differences in mortality from longitudinal studies because unbiased measures are possible to show differences in men working at different ages, retirement age, a diverse range of socioeconomic characteristics such as housing tenure and education, and geographical areas of varying socioeconomic status. The OPCS has proven to be a rich source of data. Costs will decline with improvements in technology. Statistical methods are improving. Greater familiarity breeds greater acceptance by policymakers and researchers.