Mortality, substance use disorder and cardiovascular health care in persons with severe mental illness

Abstract

<p><i>Background and aims - </i>In the Nordic countries, people with severe mental illness die 15-20 years younger than others. Substance use and higher level of undiagnosed/untreated somatic diseases contribute to this disparity. We aimed to investigate; (i) mortality among people with schizophrenia and/or substance use disorder, with emphasis on the impact of a dual diagnosis; (ii) whether people with schizophrenia or bipolar disorder had higher odds of not being diagnosed with cardiovascular disease prior to cardiovascular death, and; (iii) whether people with schizophrenia or bipolar disorder had equal prevalence of diagnostic testing and treatment of cardiovascular disease prior to cardiovascular death as people without such disorders. <p><i>Methods - </i>We calculated standardized mortality ratios in a 7-year open cohort study including all residents of Norway aged 20-79 with schizophrenia and/or substance use disorders diagnosed in specialized care (i). We used multivariate logistic (ii) and log-binomial regression (iii) to study uptake of CVD-related health care services in residents aged 18 and above. <p><i>Results - </i>We found a four-fold (schizophrenia only) to seven-fold (substance use disorder with or without schizophrenia) increased mortality compared to the general population, implicating that five out of six persons with schizophrenia and/or substance use disorder died prematurely. We also found that people with schizophrenia and women with bipolar disorder were more likely to die from undiagnosed cardiovascular disease. They also had lower prevalence of specialized cardiovascular examinations and invasive cardiovascular treatment prior to cardiovascular death, compared to individuals without schizophrenia or bipolar disorder. We found no difference in uptake of invasive cardiovascular treatment in those diagnosed with cardiovascular disease prior to death. <p><i>Conclusion - </i>The large mortality gap between persons with severe mental illness and the general population highlights the need of securing proper access to specialized somatic care, and a more effective prevention of deaths from unnatural causes in this group.