Background: Multiple Long Term conditions (MLTC) are a major health care challenge associated with high service utilisation and expenditure. Once established, the trajectory to an increased number and severity of conditions, hospital admission, increased social care need and mortality is multifactorial. The role of wider environmental determinants in the MLTC sequelae is unclear. Aim: the aim of this review was to summarise and collate existing evidence on environmental determinants on established MLTC. Methods: comprehensive search of Medline, Embase, Cochrane, CINAHL and Bielefeld Academic Search Engine (BASE), from inception to 4th June 2022 in addition to grey literature. Two authors independently screened and extracted papers. Disagreements were resolved with a third author. Results: searches yielded 9079 articles, 12 of which met the review’s inclusion criteria. Evidence of correlations between some environmental determinants and increased or decreased risks of MLTC were found, including the quality of internal housing/living environments, exposure to airborne environmental hazards and a beneficial association with socially cohesive, accessible and greener neighbourhood environments. Conclusions: The majority of the 12 included papers focused on the built and social environments. The review uncovered very limited evidence, indicating a need for further research to understand the role of environmental determinants in MLTC.

Background: Multiple Long Term conditions (MLTC), the coexistence of two or more health conditions, is a major health care challenge associated with high service utilisation and expenditure. Once established, the trajectory to an increased number and severity of conditions, hospital admission, increased social care need and mortality is multifactorial. The role of wider environmental determinants in the MLTC sequelae is unclear. Aim: The aim of this review was to summarise and collate existing evidence on environmental determinants on established MLTC. Methods: A comprehensive search of Medline, Embase, Cochrane, CINAHL and Bielefeld Academic Search Engine (BASE) from inception to 4th June 2022 in addition to grey literature. Two authors independently screened and extracted papers. Disagreements were resolved with a third author. Results: The search yielded 9,079 articles of which 12 were included. Five studies considered the effect of urban built environments and neighbourhood characteristics on MLTC. Two studies examined both the built and social environments. The social environment was considered by four studies. One study examined the natural environment. Evidence of correlations between some environmental determinants and increased or decreased risks of MLTC were found, including the quality of internal housing/living environments, exposure to airborne environmental hazards and a beneficial association with socially cohesive, accessible and greener neighbourhood environments. Conclusions: Only 12 relevant papers were identified, with the majority focused on the built and social environments. Overall, the review uncovered very limited evidence and this finding indicates a need for further research to understand the role of environmental determinants in MLTC.