Excess Mortality and Life-Years Lost in People With Schizophrenia and Other Non-affective Psychoses: An 11-Year Population-Based Cohort Study

Abstract

Psychotic disorders are associated with premature mortality, but research was primarily based on Western countries and rarely examined non-affective psychoses other than schizophrenia (ONAP). This population-based cohort study investigated excess mortality in 46 896 schizophrenia and 20 651 ONAP patients between January 2006 and December 2016 in Hong Kong (HK), by estimating all-cause and cause-specific standardized mortality ratios (SMRs), and life-years lost (LYLs), a recently developed, more precise reduced life expectancy measure taking into account the illness onset (age at first-recorded diagnosis). Changes in mortality metrics over the study period were assessed. Study data were retrieved from a territory-wide medical-record database of public healthcare services to 7.5 million HK residents. Results showed that schizophrenia and ONAP patients had higher all-cause (schizophrenia: SMR: 2.49 [95% CI: 2.43–2.55]; ONAP: 2.00 [1.92–2.09]), natural-cause (1.80 [1.74–1.85]; 1.47 [1.40–1.54]), and unnatural-cause (6.97 [6.47–7.49]; 8.53 [7.61–9.52]) mortality rates than general population. Respiratory diseases, cardiovascular diseases, and cancers accounted for the majority of deaths in patient cohorts. Men and women with schizophrenia had 9.53 years and 8.07 years of excess LYLs, respectively. For ONAP, excess LYLs was 8.18 years for men and 5.44 years for women. The overall mortality gap remained similar for both patient groups over time despite their improved longevity and declined unnatural-cause mortality rates. Taken together, schizophrenia and ONAP are associated with increased premature mortality and substantially reduced lifespan in a predominantly Chinese population, with excess deaths mainly attributed to a natural cause. Persistent mortality gap highlights an urgent need for targeted interventions to improve the physical health of patients with psychotic disorders.