The association between area-level factors and mortality in severe mental illnesses: A systematic review.

Background: Premature mortality is a well-documented adverse outcome for people living with severe mental illnesses (SMI). Emerging evidence suggests that area-level factors play a role that are experienced disproportionately by this population. This review assesses the potential association between area-level factors and mortality in people with SMI.

Method: We searched Medline, EMBASE, PsychINFO, Social Policy and Practice, Web of Science and OpenGrey databases. Literature searches were conducted in May 2020 and updated in June 2023. Reference lists were hand-searched and authors of included studies contacted to identify additional studies and minimise publication biases. Narrative synthesis was used to appraise the included studies. The review protocol was registered on PROSPERO (CRD42019155447).

Results: Our searches identified 7 studies (8 papers), which were included in the review, and indicated evidence of an association between deprivation and mortality. One study suggested an association between mortality in SMI and urbanicity in low to middle income settings which was not observed in studies from high income settings. One study suggested a protective association of area-level ethnic density with mortality within urbanised settings.

Conclusion: Consistent associations were reported between residence in areas of higher deprivation and increased risk of mortality in SMI. Two studies suggested an association between area-level ethnic density and urbanicity and mortality in SMI. Most studies were conducted across high income countries and therefore future research could benefit from similar investigations being conducted in low- and middle-income countries. These methods would inform health and social policies, including interventions to reduce premature mortality in SMI.