Abstract
BACKGROUND: The association between the frailty index (FI) and the risk of chronic lung diseases (CLDs) remains unexplored, warranting further research. METHODS AND MATERIALS: This study investigated the relationship between FI and CLD risk using data from the China Health and Retirement Longitudinal Study (CHARLS) and English Longitudinal Study of Ageing (ELSA), comprising a combined sample of 9642 individuals. Propensity score weighting was used to ensure similar distribution of covariates across FI groups. The Wilcoxon rank-sum test was used to analyze differences in FI scores between groups with and without CLD. Kaplan-Meier curves and Cox regression analysis were employed to explore the association between frailty status and CLD incidence, with sensitivity analyses conducted for validation. RESULTS: Higher FI scores were significantly associated with increased CLD risk in both cohorts (p < .05). Kaplan-Meier survival and Cox regression analyses indicated that frail individuals have a significantly elevated risk of CLD compared to robust individuals, particularly in certain subgroups (e.g., female) within the CHARLS cohort (p < .05). The ELSA cohort yielded similar results (p < .05), affirming FI as a strong predictor of CLD. Additional risk factors identified included age, smoking, and unmarried status (p < .05). Frail individuals consistently exhibited the highest risk in both cohorts (CHARLS HR = 1.54, p = .003; ELSA HR = 6.64, p < .001). The sensitivity analysis did not substantially alter the significant associations. CONCLUSION: These findings emphasize the critical role of frailty in the development of CLD, suggesting that targeted interventions could reduce CLD risk.