Sex-stratified mortality estimates in people with schizophrenia: A systematic review and meta-analysis of cohort studies of 2,700,825 people with schizophrenia

The differential influence of sex on premature mortality in schizophrenia is unclear. This study assessed the differences in all-cause and specific cause mortality risks in people with schizophrenia compared to several control groups stratified by sex. We conducted a PRISMA 2020-compliant systematic review and random-effects meta-analysis of cohort studies assessing mortality relative risk (RR) for people with schizophrenia, comparing by sex. We measured publication bias and conducted a quality assessment through the Newcastle-Ottawa scale. We meta-analyzed 43 studies reporting on 2,700,825 people with schizophrenia. Both males and females with schizophrenia had increased all-cause mortality vs. comparison groups (males, RR=2.62, 95%CI 2.35-2.92; females, RR=2.56, 95%CI 2.27-2.87), suicide (males, RR=9.02, 95%CI 5.96-13.67; females, RR=12.09, 95%CI 9.00-16.25), and natural cause mortality (males, RR=2.11, 95%CI 1.88-2.38; females, RR=2.14, 95%CI 1.93-2.38). No statistically significant differences in sex-dependent mortality risk emerged. There was an age-group-dependent increased mortality risk in females < 40 years vs. >/=40 years old (RR=4.23/2.17), and significantly higher risk of death due to neurological disorders (dementia) in males vs. females (RR=5.19/2.40). Increased mortality risks were often associated with specific modifiable risk factors. The increased mortality risk did not improve over time, calling for more studies to identify modifiable factors, and for better physical healthcare for males and females with schizophrenia.