The prevalence of schizophrenia and other psychotic disorders among homeless people: a systematic review and meta-analysis

BACKGROUND: Schizophrenia and other psychotic disorders constitute a huge global burden of disease and they are major contributors to disability as well as premature mortality among homeless people. This systematic review and meta-analysis aimed to estimate the pooled prevalence of schizophrenia and other psychotic disorders among homeless people. METHODS: PubMed, Embase, and Scopus were searched to identify pertinent studies. We used a fixed- or random-effect meta-analysis to pool data from the included studies depending on the anticipated heterogeneity. A predesigned search strategy, as well as inclusion and exclusion criteria, were used. We also performed subgroup and sensitivity analysis and Cochran’s Q- and the I(2) test was employed to compute heterogeneity. Egger’s test and visual inspection of the symmetry in funnel plots were used to assess publication bias. RESULTS: Thirty-one studies involving 51,925 homeless people were included in the final analysis. The meta-analysis showed a remarkably higher prevalence of psychosis [21.21% (95% CI:13.73, 31.29), I(2) = 99.43%], schizophrenia [10.29% (95%, CI: 6.44, 16.02), I(2) = 98.76%], schizophreniform disorder [2.48% (95% CI: 6.16, 28.11), I(2) = 88.84%] schizoaffective disorder [3.53% (95% CI: 1.33, 9.05), I(2) = 31.63%,] as well as psychotic disorders not otherwise specified [9% (95% CI: 6.92, 11.62), I(2) = 33.38%] among homeless people. The prevalence estimate of psychosis was higher in developing (29.16%) as compared to developed (18.80%) countries. Similarly, the prevalence of schizophrenia was highest in developing (22.15%) than developed (8.83%) countries. CONCLUSION: This systematic review and meta-analysis revealed that schizophrenia and other psychotic disorders are highly prevalent among homeless people, indicating an urgent need for studies to help develop better mechanisms of prevention, detection as well as treatment of those disorders among homeless people.