The interplay between climate change and ageing: A systematic review of health indicators

Research question Using the PICO strategy [36] and following Cochrane guidelines [35], the question of this review was: How do climate changes affect the physical health and well-being of the older population? Review objective The objective of this review was to identify health indicators that elucidate the unidirectional association between climate change and the physical and mental health of the older population. Data collection In March 2023, two reviewers, T.F. and L.M, independently searched and extracted data from PubMed, Scopus and Greenfile. The final search query was then constructed as: (‘old*’ OR ‘geriatr*’ OR ‘aged’ OR ‘ageing’ OR ‘aging’ OR ‘later life’ OR ‘elder*’) AND (‘individual health’ OR ‘health’ OR ‘normalit*’ OR ‘normalc*’ OR ‘illness’ OR ‘disease’ OR ‘condition’) AND (‘cli- mate change’ OR ‘global warming’ OR ‘sea level rise’ OR ‘climate adaptation’). Language restrictions were applied to include only studies published between 2015 and 2022, in English. Besides, the search was restricted only to studies about humans. All 3154 articles were reviewed by the same reviewers, who independently assessed the titles, in the first phase, then the abstracts, and finally the full text. The inclusion and exclusion criteria used throughout the selection process are described below. Inclusion and exclusion criteria When assessing the titles, articles that met one or more of the exclusion criteria listed below were not considered: 1. topics unrelated to health, climate change or/and older population; 2. subjects of the study were not humans;

3. not published in English. During the abstract and full-text analysis, the selection was based on the following inclusion and exclusion criteria: Inclusion criteria. 1. Study design: Studies that report on original research in humans (e.g., randomized con- trolled trials, observational studies, case-control studies, cross-sectional studies). 2. Population: Studies focusing on adults 65 years and older. 3. Exposure: Studies that investigate the impact of climate change on health outcomes in older adults, such as heat-related illnesses, cardiovascular and respiratory diseases, mental health, and other related outcomes. 4. Outcome: Studies that report on climate change’s effects on older adults’ health and their health-related quality of life, specifically in terms of morbidity and mortality. 5. Publication: Studies published in peer-reviewed journals. Exclusion criteria. 1. Studies that do not focus exclusively on older adults (i.e., studies that include mixed popula- tions without a focus on older adults). PLOS ONE Climate change, ageing and health PLOS ONE | https://doi.org/10.1371/journal.pone.0297116 April 24, 2024 4 / 17