The association of self-reported discrimination to all-cause mortality: A population-based prospective cohort study.

Discrimination has is an important social determinant of health and though some research has been carried out on this it is mostly from the United States, which may not be generalisable to Europe and Sweden. This study investigated the association between self-reported experiences of repeated discrimination and all-cause mortality in Scania, Sweden. The Scania Public Health survey was sent out in 2008 with a follow-up in 2013 through the Swedish national cause of death register (N=28,062). The exposure variable under investigation was self-reported discrimination and the outcome variable was all-cause mortality. Additional variables included demographics (age, sex, marital status, immigrant status), health behaviours (smoking, alcohol consumption, physical exercise), BMI, social participation, economic stress, and mental health. Time was measured as total number of days. Statistical analysis included association of the different variables to discrimination (ORs) and to all-cause mortality (HRs) adjusting for different covariates. Effect modification was tested for social participation, economic stress and mental health. The odds of discrimination was higher among the most vulnerable groups in society. All-cause mortality was strongly associated to age and sex, with a much higher risk among men than women. The association of repeated discrimination to all-cause mortality remained significant after adjusting for demographic variables, health behaviours and either social participation or economic stress, but not both. The association was non-significant after adjusting for demographic variables and mental health. Social participation was found to be an effect modifier with low participation strengthening the effect of the association of repeated discrimination to all-cause mortality. Repeated discrimination clearly has a strong impact on mental health but also on economic stress and social participation which in turn have a strong impact on mortality.