Mortality Risks in Patients With Schizophrenia in Shanghai: A Longitudinal Cohort Study

Abstract

Background: Schizophrenia is a severe mental disorder associated with significantly higher mortality risk than the general population, constituting a major public health challenge. Clarifying temporal trends in mortality among patients with schizophrenia helps inform targeted clinical and public health interventions. To assess changes in mortality rates over the last 2 years in patients with schizophrenia from one district of Shanghai, China.

Methods: This longitudinal cohort study assessed the mortality of individuals with schizophrenia (n = 5234) from April 1, 2021, to March 31, 2023. The early cohort (up to March 31, 2022) contained 5207 individuals and the late cohort (up to March 31, 2023) contained 5114 individuals. Partitions of Pearson’s chi-square statistic were used to conduct pairwise comparisons. A multivariable Cox proportional hazards model was used to assess the effects of different factors on mortality risk. Data were drawn from the official Shanghai database used for following-up individuals with severe mental health disorders.

Results: The total number of deaths was 370. Of these, 120 occurred in the early cohort (2.30% of the cohort) and 250 in the late cohort (4.89% of the cohort). Individuals with schizophrenia in the late cohort had a 5.08- fold increased mortality risk than individuals in the general population. In the early cohort, mortality rates remained relatively stable (0.29%–0.48%). There were peaks in mortality rates (2.23%) in December 2022 and January 2023. Men had a higher risk of mortality than women (hazard ratio [HR], 1.294; 95% confidence interval [CI], 1.035–1.618; p = 0.024). Age was a contributing factor to the mortality of people with schizophrenia (HR, 1.048; 95% CI, 1.040– 1.056; p < 0.001). Being unmarried (HR, 1.956; 95% CI, 1.522–2.513; p < 0.001), divorced (HR, 1.481; 95% CI, 1.010–2.170; p = 0.044), or widowed (HR, 1.334; 95% CI, 0.958–1.856; p = 0.088) was associated with a high risk of mortality. Age of onset (HR, 1.046; 95% CI, 1.037– 1.054; p < 0.001) and illness duration (HR, 1.044; 95% CI, 1.037–1.051; p < 0.001) were associated with high mortality risk. The late cohort showed a higher mortality rate than the early cohort (HR, 2.427; 95% CI, 1.467–4.014; p = 0.001). The mortality of patients with schizophrenia was notsignificantly related to education level, economic status, or symptom onset. 

Conclusions: These findings highlight trends in schizophrenia mortality since April 2021. Compared with the general population, individuals with schizophrenia had higher mortality risk, particularly adults aged ≥65 years and women with low education.