Background. The association of social and clinical indicators with employment, disability, and health outcomes among individuals with severe mental illnesses (SMI) remains unclear. Existing evidence primarily comes from smaller cohort studies limited by shorter follow-up and high attrition, or registry-based research, which lacks information on important social determinants.

Study Design. We utilized a novel data linkage consisting of clinical records of individuals diagnosed with schizophrenia-spectrum or bipolar disorders from the South London and Maudsley Mental Health Trust, linked at the individual-level to the 2011 UK Census, a rich source for sociodemographic information. Using logistic regression, we estimated adjusted odds ratios (aORs) and 95% confidence intervals to determine associations between socioeconomic and clinical indicators and economic inactivity, self-rated health, and disability outcomes.

Results. The sample comprised 8249 people with SMI diagnoses. Economic inactivity (77.3%), disability (68.3%) and poor health (61.1%) were highly prevalent. Longer duration of illness and comorbid substance misuse were associated with economic inactivity, poorer self-rated health, and disability, with associations noted between living alone and all outcomes (aORs and 95% CI: Economic inactivity: 1.72, 1.45-2.03; disability: 1.48, 1.31-1.68; poor health: 1.32, 1.18-1.49). Relative to the White British group, Black African, South Asian, and Other Black groups were more likely to be economically inactive. Black Caribbean and other groups were less likely to report poorer self-rated health or disability.

Conclusions. Our findings highlight considerable disability, poorer health, and economic inactivity experienced by people with SMI. Addressing comorbid substance misuse and social isolation could play a role in improving outcomes.