Impact of heatwaves on health-related quality of life in older Chinese adults : a longitudinal cohort study

Abstract

Objectives: Climate change has intensified heatwaves, posing significant health risks to older adults, yet their impact on health-related quality of life (HRQoL) in China’s aging population remains underexplored. This study investigates the impact of heatwaves on HRQoL among older adults using the EQ-5D-5L. Methods: A cohort of community-dwelling Chinese adults aged≥60 years were followed up from spring to fall in 2023. Univariate regression and restricted cubic spline models analyzed linear and non-linear relationships between meteorological/demographic factors and EQ-5D-5L outcomes (utility values and EQ VAS scores). Machine learning models identified key predictors of heatwave-related HRQoL changes. Results: Among the 627 participants, both EQ-5D-5L utility values and EQ VAS scores followed a rise-and-fall pattern, initially increasing during the early heatwave period (T1) but subsequently declining significantly during the peak heatwave period (T2) (P<0.001). Underweight individuals had lower utility values (β=-0.394, P=0.006), while obese individuals had lower EQ VAS scores (β=-0.385, P=0.040). Age was negatively associated with both utility values (β=-0.003, P<0.001) and EQ VAS scores (β=-0.228, P<0.001). Meteorological factors, such as daily average relative humidity and temperature significantly affected both EQ-5D-5L utility values and EQ VAS scores (P<0.05). The Support Vector Machine model outperformed the other machine learning models, identifying body mass index as the most influential variable in predicting the EQ-5D-5L utility values, followed by age, pre-retirement occupation, education level, and daily average relative humidity. Conclusion: Heatwaves dynamically affect HRQoL in older adults in China, with an initial increase followed by a significant decline. Older, underweight, and less-educated adults are more vulnerable to the adverse impacts of heatwaves on HRQoL.