Cause and rate of death in people with schizophrenia across the lifespan: a population-based study in Manitoba, Canada

Abstract

Objective: To compare the causes and rates of death for people with and without schizophrenia in Manitoba, Canada.

Method: Using de-identified administrative databases at the Manitoba Centre for Health Policy, a population-based analysis was performed to compare age- and sex-adjusted 10-year (1999-2008) mortality rates, overall and by specific cause, of decedents aged 10 years or older who had 1 diagnosis of schizophrenia (ICD-9-CM code 295, ICD-10-CA codes F20, F21, F23.2, F25) over a 12-year period (N = 9,038) to the rest of the population (N = 969,090).

Results: The mortality rate for those with schizophrenia was double that of the rest of the population (20.00% vs. 9.37%). The all-cause mortality rate was higher for people with schizophrenia compared to all others (168.9 vs. 99.1 per thousand; relative risk [RR] = 1.70, P < .0001); rates of death due to suicide (RR = 8.67, P < .0001), injury (RR = 2.35, P < .0001), respiratory illness (RR = 2.00, P < .0001), and circulatory illness (RR = 1.64, P < .0001) were also significantly higher in people with schizophrenia. Overall cancer deaths were similar (28.6 vs. 27.3 per thousand, P = .42, NS) except in the middle-aged group (40-59), in which cancer death rates were significantly higher for those with schizophrenia (28.7 vs. 11.6 per thousand; RR = 2.48, P < .01). Mortality rates due to lung cancer were significantly higher in people with schizophrenia (9.4 vs. 6.4 per thousand, RR = 1.45, P < .001).

Conclusions: People with schizophrenia are at increased risk of death compared to the general population, and the majority of these deaths are occurring in older age from physical disease processes. Risk of cancer mortality is significantly higher in middle-aged but not younger or older patients with schizophrenia. Understanding these patients' vulnerabilities to physical illness has important public health implications for prevention, screening, and treatment as the population ages.