Relationships between frailty, housing characteristics, and heat-health outcomes in community-dwelling older adults in Hong Kong.

Background and Objectives: Previous evidence showed that frailty in older age and precarious housing characteristics, respectively, contribute to poorer heat-related health outcomes. It is not known whether these conditions would interact with each other to produce a larger impact on older people's health. Research Design and Methods: A cross-sectional questionnaire survey was conducted in May-July 2024 in a sample of older people aged 60 or over in Hong Kong, a city on the Southern coast of China. Frailty was measured using the Fried phenotype (five items). Housing characteristics were measured by whether it is a small flat (<100 square feet per person), living alone, inadequate housing (subdivided units or other forms), or whether the respondent had an air conditioner at home. Heat-related health outcomes were self-rated health, thermal comfort at home, and any heat-related signs/symptoms during summertime. Multivariable Poisson regression with robust standard error was used. Relative risk due to interaction was used to characterize additive interaction between housing characteristics and frailty. Results: Among the 1,393 respondents who completed the questionnaire, about 60% reported being frail. Those who were frail were less likely to report thermally comfortable at home (RR: 0.75; 95% CI: 0.66, 0.87) and had a higher chance of reporting any heat-related signs/symptoms (RR: 1.28; 95% CI: 1.18, 1.38). We found evidence of additive interaction between frailty and living alone, in which, only for those who were robust, living alone is related to a lower risk of heat-related signs/symptoms. Discussion and Implications: Targeted interventions to improve the well-being of community-dwelling older adults during periods of extreme heat should be designed especially for those who are frail.