Pneumoconiosis patients have a higher prevalence of chronic obstructive pulmonary disease (COPD). While age is a known associated factor, its impact across different populations is unclear. We included 9,964 pneumoconiosis patients from 27 Chinese provinces. Factors were identified using multivariable logistic regression, and the non-linear age–COPD association was examined with restricted cubic spline (RCS) modelling. Stratified analysis and interaction tests assessed sociodemographic heterogeneity. Sensitivity analyses comprised RCS models with varying knots and propensity score matching. The prevalence of COPD among patients with pneumoconiosis was 24.1%. Each additional year of age was associated with a significant increase in the odds of COPD (adjusted odds ratio aOR = 1.03, 95% confidence interval CI: 1.03–1.04). RCS analysis revealed a significant nonlinear relationship, with the odds increasing more steeply at older ages ( P for overall < 0.001; P for nonlinear = 0.002). Subgroup analyses showed substantial heterogeneity in these associations. Among urban residents and individuals covered by work-related injury insurance (WRII), the odds of COPD increased sharply and then gradually plateaued in later life. In contrast, among rural residents and those without WRII, the odds increased steadily with advancing age. Sensitivity analyses confirmed the robustness of these findings. The nonlinear relationship between age and COPD in pneumoconiosis in patients with pneumoconiosis is significantly modified by sociodemographic factors.
Liu et al. (Fri,) studied this question.