Association between the temperature difference and acute exacerbation of chronic obstructive pulmonary disease in Lanzhou, China.

The aim of this study was to use the distributed lag non-linear model (DLNM) to investigate the association between temperature differences (including temperature change between neighboring days (TCN) and diurnal temperature range (DTR)) and acute exacerbation of chronic obstructive pulmonary disease (AECOPD) outpatient visits. We also stratify by sex (male, female) and age (< 65 years, 65-74 years and ≥ 75 years). The results showed that the maximum relative risk (RR) of low temperature for AECOPD outpatient visits was 1.175 (95% CI: 1.095-1.261) at lag 0. Risk estimates showed that the RR of AECOPD outpatient visits with extremely high DTR at lag 10 days was 1.017 (95% CI: 1.001-1.035). As for TCN, the risk of outpatient in AECOPD patients was found when exposed to low TCN with the most significant single-day effect at lag 0 (RR = 1.051, 95% CI: 1.016-1.088). Overall, the elderly (≥ 75 years) and males were more susceptible to lower temperature, lower TCN, and higher DTR than females, patients aged < 65 years and patients aged 65-74 years. This study concluded that exposure to low temperature, high DTR and low TCN were associated with an increased risk of AECOPD outpatient visits, indicating that patients with AECOPD need to take proactive actions in the face of temperature variation. Special consideration should be given to vulnerable populations, including males and the elderly (≥ 75 years).