Quality of medical care and excess mortality in psychiatric patients—a nationwide register-based study in Sweden

OBJECTIVE To assess overall and cause-specific mortality and the quality of somatic care among psychiatric patients. DESIGN A register-based cohort study. SETTING All individuals aged 20-79 years in Sweden in 2005. PARTICIPANTS In total 6 294 339 individuals. PRIMARY OUTCOME MEASURE The individuals were followed for mortality in 2006 and 2007, generating 72 187 deaths. Psychiatric patients were grouped according to their diagnosis in the National Patient Register. Mortality risk of psychiatric patients was compared with that of non-psychiatric patients. Estimates of RR of mortality were calculated as incidence rate ratios (IRRs) with 95% CIs using Poisson regression analysis. Psychiatric patients were compared with non-psychiatric patients for three healthcare quality indicators: the proportion of avoidable hospitalisations, case death rate after myocardial infarction and statin use among diabetic patients. RESULTS Compared with individuals with no episodes of treatment for mental disorder, psychiatric patients had a substantially increased risk of all studied causes of death as well as death from conditions considered amenable to intervention by the health service, that is, avoidable mortality. The highest mortality was found among those with another mental disorder, predominantly substance abuse (for women, an IRR of 4.7 (95% CI 4.3 to 5.0) and for men, an IRR of 4.8 (95% CI 4.6 to 5.0)). The analysis of quality of somatic care revealed lower levels of healthcare quality for psychiatric patients, signalling failures in public health and medical care. CONCLUSION This study shows a marked increase in excess mortality, suggesting a lower quality of somatic healthcare in psychiatric patients.