Mortality in schizophrenia and other psychosis: Data from the South Korea NHI cohort, 2002-2013

Abstract

Individuals with psychoses show excess mortality, which is a major public health concern. This study examined all-cause and suicide mortality rates in Korean patients diagnosed with schizophrenia, mood disorder, or mental and behavioral disorder due to psychoactive substance use and to compare this with that of the general population. Data were from the National Health Insurance cohort, 2002 to 2013. A total of 107,190 cases aged 15 years or over were included. Mortality rates per 100,000 person years (PY) were obtained. Poisson regression modelling was conducted to quantify the effect of baseline characteristics on all-cause and suicide mortality risks. Standardized mortality ratios (SMRs) were also calculated. All-cause mortality was the highest among mental and behavioral disorder patients (1,051.0 per 100,000 PY), followed by schizophrenia (949.1 per 100,000 PY) and mood disorder patients (559.5 per 100,000 PY). Highest suicide mortality was found in schizophrenia (177.2 per 100,000 PY), mental and behavioral disorder (143.7 per 100,000 PY), and mood disorder patients (59.7 per 100,000 PY). The rate ratios (RRs) for all-cause and suicide mortality were reduced for younger populations and women. Psychoses patients had higher all-cause (schizophrenia, SMR 2.4; 95% confidence interval [CI] 2.2–2.5; mood disorder, SMR 1.4; 95% CI 1.3–1.5; mental and behavioral disorder, SMR 2.6; 95% CI 2.5–2.8) and suicide (schizophrenia, SMR 8.4; 95% CI 7.2–9.6; mood disorder, SMR 2.8; 95% CI 2.1–3.5; mental and behavioral disorder, SMR 6.8; 95% CI 5.7–7.9) mortality rates than the general population. These findings infer that efforts should be made to reduce excess mortality in psychoses.