Guerriero M, et al. - Researchers used data from a cross-sectional study to determine asthma–chronic obstructive pulmonary disease (COPD) overlap (ACO) prevalence in a general population sample. They also compared patient and clinical characteristics in cases with ACO, COPD, and asthma. The definition of ACO was airway obstruction (AO) (Forced Expiratory Volume in one second–FEV₁/ Forced Vital Capacity–FVC < Lower Limit of Normal–LLN), highly positive bronchodilator test (≥15% increase in FEV₁ and FVC ≥400 mL). Also, personal self-reported history of physician diagnosed asthma and atopy also defined ACO. This study included overall 1,236 patients, including 207 (16.7%) with asthma, COPD, or ACO. Findings revealed 2.1% as the estimated prevalence of ACO in Northern Italy, this estimate was in the range of values stated by past investigations. Based on spirometry findings, differences were found between ACO and COPD patients, especially post-bronchodilator FEV₁ reversibility, which was seen in ACO and asthma patients but not in those with COPD.