Household fuel use and incident chronic respiratory disease among middle-aged and older Chinese adults: findings from CHARLS

Household polluted-fuel use has been associated with adverse respiratory outcomes, but longitudinal evidence in ageing populations remains limited. We analysed five waves of the China Health and Retirement Longitudinal Study. Among 5,712 adults aged ≥ 45 years who were free of chronic respiratory disease (CRD) at baseline and had complete primary-analysis data, household fuel use was assessed in 2011 and incident CRD through 2020. Cox proportional hazards models were used for the primary analysis. During follow-up, 889 participants developed CRD. Polluted-fuel use was associated with a modestly higher hazard of incident CRD after full adjustment (HR = 1.23, 95% CI = 1.04–1.46). A multiple-imputation sensitivity analysis in the broader age-eligible cohort yielded an association in the same direction but a larger point estimate (HR = 1.35, 95% CI = 1.20–1.52). ADL and IADL impairment assessed in 2013 were examined in secondary exploratory fixed-window analyses. These analyses did not incorporate event time or censoring and therefore do not provide evidence of survival mediation by functional impairment. Overall, the findings support a modest observational association whose precise magnitude remains uncertain because of missing-data handling, residual confounding, and other potential biases.