Risk factors for disability pension over 11 years in a cohort of young persons initially sick-listed with low back, neck, or shoulder diagnoses

Aim: A study was undertaken to ascertain whether the differences in risk in relation to gender and citizenship observed in a previous study of the same cohort would remain if more recent data on sickness absence were used. Methods: This was an 11-year prospective population-based cohort study. The dataset includes all individuals in a Swedish city who, in 1985, were aged 25 - 34 and had a sick-leave spell greater than or equal to 28 days with neck, shoulder, or back diagnoses ( n = 213). The data covered the following: for 1985 - 96, disability pension, emigration, and death; for 1982 - 96, sickness absence; for 1985, sex and citizenship. The data were subjected to Cox regression analyses with a time-dependent covariate. Results: Disability pension was granted to 22% (n = 46) of the cohort. The relative risk for disability pension increased by 9.3 with each sick-leave spell greater than or equal to 90 days during the two previous years. The risk was higher for women than men, and also higher for foreign citizens than Swedes. Conclusion: Many studies have revealed a gender difference in the risk of being on disability pension, and it was found that this difference was still apparent when sick leave during the follow-up period is taken into account. Thus, the reason for the gender differences ought to be found among other factors than prior levels of sickness absence.