Socioeconomic inequalities and mortality among disability pensioners in Norway – a population-based cohort study

Abstract

Background: The study assessed the mortality related to disability pension (DP) status in Norway during 1990-96 and investigated whether socioeconomic factors explained the increased mortality. Methods: A 10% random sample of the Norwegian population aged 30-59 years, 73,420 women and 75,500 men, were followed-up with respect to death or emigration in 1990-96. DP-status, age, gender, educational level and mean income before inclusion were used as explanatory variables in Cox’ regression analysis with death as endpoint. The analyses were stratified for gender and separately for persons who had obtained DP before 1985 (early) and in 1985-1989 (late). Results: The majority of persons with DP had only basic education and belonged to the lowest income level. Among the women 6.2% in the DP-group died during follow-up compared to 1.2% of those in the non-DP group. The corresponding percentages for men were 14.5% and 2.3%. The age-adjusted hazard ratios (HRs) were 3.5 and 2.5 for women with early and late DP, and 4.3 and 3.3 among men. After adjustment for socioeconomic variables, the HRs were 2.9 and 2.2 for women, and 2.2 and 1.9 for men. Conclusions: Nearly half of the excess mortality related to DP-status was explained by low socioeconomic status among the men. Among women, HR related to DP was not significantly reduced after the adjustments for socioeconomic variables. These findings indicate a strong impact of the medical factors underlying the DP decision, especially among women, but also an important role of the socioeconomic factors related to DP status.