Cardiovascular disease in patients with schizophrenia in Saskatchewan, Canada

Abstract

Background: Studies have shown that patients with schizophrenia have higher rates of cardiovascular disease and mortality compared with the general population. However, population-based data on the prevalence, incidence, and mortality of cardiovascular disease are needed.

Method: In this retrospective cohort study, the Saskatchewan Health databases were searched for all patients diagnosed with schizophrenia (ICD-9 code 295) in 1994 or 1995. 3022 subjects were identified. For each subject, 4 age- and sex-matched comparison individuals were selected randomly among residents of the province who had no diagnosis of schizophrenia or any other mental disorders and who received no prescriptions for antipsychotic medications. Prevalence of cardiovascular morbidity during 1994 and 1995 and incidence of cardiovascular morbidity and mortality during the follow-up period of January 1996 through March 1999 were analyzed.

Results: Concerning prevalence of morbidity in schizophrenia patients, significantly increased risk-adjusted odds ratios were as follows: arrhythmia, 1.5 (95% CI = 1.2 to 1.8); syncope, 4.0 (95% CI = 2.0 to 7.9); heart failure, 1.7 (95% CI = 1.4 to 2.2); stroke, 2.1 (95% CI = 1.6 to 2.7); transient cerebral ischemia, 2.6 (95% CI = 1.7 to 3.7); and diabetes, 2.1 (95% CI = 1.8 to 2.4). Odds of acute myocardial infarction, ischemic heart disease, and ventricular arrhythmias were not significantly different from those for the comparison group. Concerning incidence of morbidity and mortality in the patients, adjusted relative risk was significantly increased for ventricular arrhythmia, 2.3 (95% CI = 1.2 to 4.3); heart failure, 1.6 (95% CI = 1.2 to 2.0); stroke, 1.5 (95% CI = 1.2 to 2.0); diabetes, 1.8 (95% CI = 1.2 to 2.6); all-cause mortality, 2.8 (95% CI = 2.3 to 3.4); and cardiovascular mortality, 2.2 (95% CI = 1.7 to 2.8).

Conclusions: Persons with schizophrenia appear to be at greater risk for cardiovascular morbidity and mortality than those in the general population.