A systematic review of cough classifications: Evidence-based approaches to managing acute, subacute, and chronic cough in adults

This systematic review evaluates the classification and management algorithms for acute, subacute, and chronic cough in adults based on the American College of Chest Physicians (CHEST) guidelines. The analysis focuses on the 2006 CHEST Cough Guidelines, which categorize coughs by duration—acute (< 3 weeks), subacute (3-8 weeks), and chronic (> 8 weeks). The review used the Population, Intervention, Comparison, and Outcome (PICO) framework to assess the utility of these classifications in diagnosing and managing adult patients globally.

The findings suggest that the 2006 cough classifications and associated management strategies have been widely adopted in clinical practice across multiple continents. For acute cough, respiratory infections, often viral, were the most common cause, while subacute cough was predominantly linked to postinfectious cough and exacerbations of chronic conditions such as asthma and COPD. Chronic cough was primarily associated with upper airway cough syndrome (UACS), asthma, gastroesophageal reflux disease (GERD), and non-asthmatic eosinophilic bronchitis (NAEB). These findings confirm the utility of the 2006 guidelines, though updated algorithms now reflect emerging evidence, including the management of cough due to tuberculosis and the use of validated cough severity assessment tools.

Although the review identified several areas where the guidelines performed well, it also highlighted the need for more high-quality studies, particularly those that incorporate validated outcome measures and control groups. The 2018 updates to the CHEST guidelines address these gaps by refining diagnostic algorithms and emphasizing the importance of red flag symptoms, environmental and occupational factors, and validated tools for assessing cough severity and quality of life.