The Contribution of Alcohol Use, Other Lifestyle Factors and Working Conditions to Socioeconomic Differences in Sickness Absence.

Introduction: This study investigates how alcohol use contributes to the social gradient in sickness absence. Other factors assessed include lifestyle factors (smoking, physical activity and body mass index), physical and psychosocial working conditions.

Methods: The study used baseline data from the Stockholm public health cohort 2006, with an analytical sample of 17,008 respondents aged 25-64 years. Outcome variables included self-reported short-term (<14 days) and register-based long-term (>14 days) sickness absence. Socioeconomic position (SEP) was measured by occupational class. Alcohol use was measured by average weekly volume and frequency of heavy episodic drinking. Negative binominal regression was used to estimate sex-specific SEP differences in sickness absence, before and after adjusting for alcohol use and the additional explanatory factors.

Results: Adjusting for alcohol use attenuated the SEP differences in long-term sickness absence by 20% for men and 14% for women. Alcohol use explained a smaller proportion of the differences in short-term sickness absence. Alcohol use in combination with other lifestyle factors attenuated the SEP differences (20-35%) for both outcomes. Physical working conditions explained more than half of the gradient in long-term sickness absence, whereas psychosocial conditions had greater impact on short-term sickness absence among men.

Discussion/conclusion: Alcohol use explains a substantial proportion of the SEP disparities in long-term sickness absence among men. The effect is smaller among women and for short-term sickness absence. Our findings support the notion that physical working conditions constitute the key explanatory variable for SEP differences in long-term sickness absence, but add that psychosocial working conditions have greater impact on the gradient in short-term sickness absence among men.