Socioeconomic status across the life course and all-cause and cause-specific mortality in Finland

Highlights

• We study impact of childhood and adult socio-demographic conditions on mortality.

• The study is based on 1935–1950 birth cohorts in Finland.

• We find childhood conditions to be significant predictors of adult mortality.

• Adult educational attainment and occupation mediated these associations.

• Impact of adult attributes was robust for controls of childhood conditions.

Abstract

We used high quality register based data to study the relationship between childhood and adult socio-demographic characteristics and all-cause and cause-specific mortality at ages 35–72 in Finland among cohorts born in 1936–1950. The analyses were based on a 10% sample of households drawn from the 1950 Finnish Census of Population with the follow-up of household members in subsequent censuses and death records beginning from the end of 1970 through the end of 2007. The strengths of these data come from the fact that neither childhood nor adult characteristics are self reported and thus are not subject to recall bias, misreporting and no loss to follow-up after age 35. In addition, the study population includes several families with at least two children enabling us to control for unobserved family characteristics. We documented significant associations between early life social and family conditions on all-cause mortality and cause-specific mortality, with protective effects of higher childhood socio-demographic characteristics varying between 10% and 30%. These associations were mostly mediated through adult educational attainment and occupation, suggesting that the indirect effects of childhood conditions were more important than their direct effects. We further found that adult socioeconomic status was a significant predictor of mortality. The associations between adult characteristics and mortality were robust to controls for observed and unobserved childhood characteristics. The results imply that long-term adverse health consequences of disadvantaged early life social circumstances may be mitigated by investments in educational and employment opportunities in early adulthood.

Introduction

Socioeconomic (SES) inequalities in mortality have been extensively documented (Cutler et al., 2008, Elo, 2009) but factors that underlie these differentials continue to be debated. Until recently, most studies of SES inequalities in adult mortality focused on the role of adult characteristics. However, as evidence of the associations between childhood conditions and adult health has accumulated, increased attention is now being paid to the contribution of entire life course to adult health inequalities (e.g., Elo and Preston, 1992, Haas, 2008, Hayward and Gorman, 2004, Næss et al., 2012, Palloni et al., 2009). This evidence suggests that childhood nutritional status, health, SES, place of residence and other household characteristics contribute to adult disparities in health and mortality (Case et al., 2005, Galobardes et al., 2004, Galobardes et al., 2008, Laaksonen et al., 2005, Osler et al., 2005). Among the mechanisms through which childhood environment is hypothesized to influence adult health include indirect mechanisms operating through attained adult characteristics (e.g., SES and lifestyle factors) and direct effects of childhood health (Preston, Hill, & Drevenstedt, 1998).

In this paper, we examine (1) the associations between childhood family characteristics and all-cause and cause-specific mortality in Finland, (2) whether these associations are indirect operating through attained adult SES, and (3) whether the associations between adult SES and mortality are robust to controls for observed and unobserved childhood characteristics. The data come from a unique register based data that consist of a 10% sample of households drawn from the 1950 Finnish Census of Population with follow-up of household members in subsequent censuses and death records beginning in the end of 1970 through December 31, 2007. This paper contributes to related literatures concerning the role of childhood conditions and adult SES and all-cause and cause-specific mortality in several ways. First, all information on childhood and adult characteristics are drawn from census records and thus are not subject to recall or misreporting bias or loss to follow-up after the beginning of the follow-up at age 35. Second, we are able to follow the oldest members of the study cohorts from early childhood to age 72. Third, we have sufficient sample size to study both all-cause and cause-specific mortality. Finally, we are able to analyze the impact of unobserved family characteristics on adult SES differences in mortality by comparing siblings.