Data from: Cough frequency during treatment associated with baseline cavitary volume and proximity to the airway in pulmonary tuberculosis

Background: Cough frequency, and its duration, is a lab-free biomarker that can be used in low-resource settings and has been associated with transmission and treatment response. Radiological characteristics associated with increased cough frequency may be important in understanding transmission. The relationship between cough frequency and cavitary lung disease has never been studied. Methods: We analyzed 41 human immunodeficiency virus-negative adults with culture-confirmed, drug-susceptible pulmonary tuberculosis throughout treatment. Cough recordings were based on the Cayetano Cough Monitor and sputum samples were evaluated using microscopic-observation drug susceptibility broth culture, among culture-positive samples bacillary burden was assessed by time to positivity. Computerized tomography scans were analyzed by a U.S. board-certified radiologist and an automated-computer algorithm. The algorithm evaluates cavity volume and cavitary proximity to the airway. Computerized tomography scans were taken within one month of treatment initiation. We compared small cavities (≤7-mL) versus large cavities (>7-mL) and cavities located closer to (≤10-mm) and farther (>10-mm) from the airway to cough frequency and cough cessation until treatment day 62. Results: Cough frequency during treatment was two-fold higher in participants with large cavity volumes (Rate Ratio [RR]=1.98, p=0.01) and cavities located closer to the airway (RR=2.44, p=0.001). Comparably, cough ceased three times faster in smaller cavities (adjusted hazard ratio [HR]=2.89, p=0.06) and those farther from the airway (adjusted HR=3.61, p=0.02). Similar results are found for bacillary burden and culture conversion during treatment. Conclusions: Cough frequency during treatment is greater and lasts for longer in patients with larger cavities, especially those closer to the airway.