Epidemiology and risk factors of asthma-chronic obstructive pulmonary disease overlap in low- and middle-income countries

Background Asthma‐chronic obstructive pulmonary disease (COPD) overlap (ACO) represents the confluence of bronchial airway hyperreactivity and chronic airflow limitation and has been described as leading to worse lung function and quality of life than found with either singular disease process. Objective We aimed to describe the prevalence and risk factors for ACO among adults across 6 low‐ and middle‐income countries (LMICs). Methods We compiled cross‐sectional data for 11,923 participants aged 35 to 92 years from 4 population‐based studies in 12 settings. We defined COPD as postbronchodilator FEV1/forced vital capacity ratio below the lower limit of normal, asthma as wheeze or medication use in 12 months or self‐reported physician diagnosis, and ACO as having both. Results The prevalence of ACO was…