gms | German Medical Science

Background: Increased physical comorbidity is one of the major reasons for excess mortality in individuals with schizophrenia. Cardiovascular comorbidity is considered a major modifiable risk factor to improve physical health and survival in these patients. Population-based studies in this area are sparse.

The objective of the presented study was to examine the incidence of drugs used in cardiovascular disease (CVD drugs) in subjects with schizophrenia compared with the general population and its impact on mortality.

Materials and methods: We performed a register-based population-based cohort study based on a 25% sample of the Danish population between 1995 and 2007 using data on prescriptions for CVD drugs (betablockers (BB), diuretics (DIU), drugs acting on the renin-angiotensin system (ACE), calcium channel blockers (CCBs), lipid modifying drugs (LIP) and aspirin), hospitalizations and mortality. Individuals without CVD drug use between 1995 and 1997 were followed from Jan 1, 1998 to first prescription of CVD drug classes (not mutually exclusive), emigration, death or end of study period, whatever came first. Using Poisson regression analysis, we calculated incidence rate ratios (IRRs) and mortality rate ratios (MRRs) adjusted for gender, age, calendar time, and Charlson Index comparing subjects with schizophrenia with subjects with no prior psychiatric hospitalization.

Results: The IRR for prescription of any kind of CVD drug was 1.13 (95% confidence interval (CI): 1.05, 1.21) in subjects with schizophrenia, due to increased use of DIU. IRRs were significantly decreased for LIP, BB, ACE, and CCB compared with the general population. In individuals with schizophrenia using CVD drugs the MRR was 2.82 (95% CI: 2.54, 4.00) compared with individuals in the general population using CVD drugs, while excess mortality was 5.02 (95% CI: 4.63; 5.45) in subjects with schizophrenia without prescriptions for CVD drugs compared with the general population not using CVD drugs.

Conclusions: Excess mortality was by almost 50% decreased in individuals with schizophrenia treated with CVD drugs compared with the excess mortality in subjects with schizophrenia not treated with CVD drugs. Our results further indicate potential undertreatment with LIP, BB, ACE and CCB in these patients.