Regional differences in mortality risk and in attenuating or aggravating factors in schizophrenia: A systematic review and meta-analysis.

People with schizophrenia die prematurely, yet regional differences are unclear. PRISMA 2020-compliant systematic review/random-effects meta-analysis of cohort studies assessing mortality relative risk (RR) versus any control group, and moderators, in people with ICD/DSM-defined schizophrenia, comparing countries and continents. We conducted subgroup, meta-regression analyses, and quality assessment. The primary outcome was all-cause mortality. Secondary outcomes were suicide-, /natural-cause- and other-cause-related mortality. We included 135 studies from Europe (n = 70), North-America (n = 29), Asia (n = 33), Oceania (n = 2), Africa (n = 1). In incident plus prevalent schizophrenia, differences across continents emerged for all-cause mortality (highest in Africa, RR=5.98, 95 %C.I.=4.09-8.74, k = 1, lowest in North-America, RR=2.14, 95 %C.I.=1.92-2.38, k = 16), suicide (highest in Oceania, RR=13.5, 95 %C.I.=10.08-18.07, k = 1, lowest in North-America, RR=4.4, 95 %C.I.=4.07-4.76, k = 6), but not for natural-cause mortality. Europe had the largest association between antipsychotics and lower all-cause mortality/suicide (Asia had the smallest or no significant association, respectively), without differences for natural-cause mortality. Higher country socio-demographic index significantly moderated larger suicide-related and smaller natural-cause-related mortality risk in incident schizophrenia, with reversed associations in prevalent schizophrenia. Antipsychotics had a larger/smaller protective association in incident/prevalent schizophrenia regarding all-cause mortality, and smaller protective association for suicide-related mortality in prevalent schizophrenia. Additional regional differences emerged in incident schizophrenia, across countries, and secondary outcomes. Significant regional differences emerged for all-cause, cause-specific and suicide-related mortality. Natural-cause death was homogeneously increased globally. Moderators differed across countries. Global initiatives are needed to improve physical health in people with schizophrenia, local studies to identify actionable moderators.

Mortality in people with schizophrenia: a systematic review and meta-analysis of relative risk and aggravating or attenuating factors.

People with schizophrenia die 15-20 years prematurely. Understanding mortality risk and aggravating/attenuating factors is essential to reduce this gap. We conducted a systematic review and random-effects meta-analysis of prospective and retrospective, nationwide and targeted cohort studies assessing mortality risk in people with schizophrenia versus the general population or groups matched for physical comorbidities or groups with different psychiatric disorders, also assessing moderators. Primary outcome was all-cause mortality risk ratio (RR); key secondary outcomes were mortality due to suicide and natural causes. Other secondary outcomes included any other specific-cause mortality. Publication bias, subgroup and meta-regression analyses, and quality assessment (Newcastle-Ottawa Scale) were conducted. Across 135 studies spanning from 1957 to 2021 (schizophrenia: N=4,536,447; general population controls: N=1,115,600,059; other psychiatric illness controls: N=3,827,955), all-cause mortality was increased in people with schizophrenia versus any non-schizophrenia control group (RR=2.52, 95% CI: 2.38-2.68, n=79), with the largest risk in first-episode (RR=7.43, 95% CI: 4.02-13.75, n=2) and incident (i.e., earlier-phase) schizophrenia (RR=3.52, 95% CI: 3.09-4.00, n=7) versus the general population. Specific-cause mortality was highest for suicide or injury-poisoning or undetermined non-natural cause (RR=9.76-8.42), followed by pneumonia among natural causes (RR=7.00, 95% CI: 6.79-7.23), decreasing through infectious or endocrine or respiratory or urogenital or diabetes causes (RR=3 to 4), to alcohol or gastrointestinal or renal or nervous system or cardio-cerebrovascular or all natural causes (RR=2 to 3), and liver or cerebrovascular, or breast or colon or pancreas or any cancer causes (RR=1.33 to 1.96). All-cause mortality increased slightly but significantly with median study year (beta=0.0009, 95% CI: 0.001-0.02, p=0.02). Individuals with schizophrenia <40 years of age had increased all-cause and suicide-related mortality compared to those ≥40 years old, and a higher percentage of females increased suicide-related mortality risk in incident schizophrenia samples. All-cause mortality was higher in incident than prevalent schizophrenia (RR=3.52 vs. 2.86, p=0.009). Comorbid substance use disorder increased all-cause mortality (RR=1.62, 95% CI: 1.47-1.80, n=3). Antipsychotics were protective against all-cause mortality versus no antipsychotic use (RR=0.71, 95% CI: 0.59-0.84, n=11), with largest effects for second-generation long-acting injectable anti-psychotics (SGA-LAIs) (RR=0.39, 95% CI: 0.27-0.56, n=3), clozapine (RR=0.43, 95% CI: 0.34-0.55, n=3), any LAI (RR=0.47, 95% CI: 0.39-0.58, n=2), and any SGA (RR=0.53, 95% CI: 0.44-0.63, n=4). Antipsychotics were also protective against natural cause-related mortality, yet first-generation antipsychotics (FGAs) were associated with increased mortality due to suicide and natural cause in incident schizophrenia. Higher study quality and number of variables used to adjust the analyses moderated larger natural-cause mortality risk, and more recent study year moderated larger protective effects of antipsychotics. These results indicate that the excess mortality in schizophrenia is associated with several modifiable factors. Targeting comorbid substance abuse, long-term maintenance antipsychotic treatment and appropriate/earlier use of SGA-LAIs and clozapine could reduce this mortality gap.