Meteorological factors affect pneumonia-related clinical encounters in asthma patients: Identification of vulnerable subgroups in a prospective multicentre study

Background Asthma increases the risk of clinical encounters due to community-acquired pneumonia (CAP). This study aimed to quantify the influence of meteorological exposures on CAP-related clinical encounter risk among asthma patients, with further stratification by key patient characteristics to identify vulnerable subgroups. Methods This prospective multicentre cohort study (CAPNETZ) enrolled asthmatic and non-asthmatic adults (≥18 years) with CAP resulting in a clinical encounter in Germany between 2003 and 2017. Meteorological exposures over the preceding seven days were quantified using spatial weather data. Associations between meteorological exposures and clinical encounter risk were analysed by multivariable logistic regression in subgroups defined by age, obesity, smoking, and comorbidities. Results 9,723 patients, including 3,061 with asthma, were enrolled. An average temperature below –2.6°C prior to the encounter was associated with increased encounter risk among asthma patients (relative risk [RR] 1.42, p=0.0166). Subgroup analyses revealed the highest risks for asthma patients with heart failure (RR=3.74, p