Risk factors for recurrent spontaneous pneumothorax: A population level analysis.

Background: We sought to determine the rate and risk factors of recurrent spontaneous pneumothorax in a diverse population.

Methods: Cohort study using the California Public Discharge Data file (1995-2010). We identified patients with first-time spontaneous pneumothorax. The primary outcome was recurrent pneumothorax. Associations with clinical, patient, and hospital characteristics were assessed using Cox regression analysis.

Results: Among 14,609 patients with a first-time episode of spontaneous pneumothorax, 26.2% developed a recurrence. Risk factors included age <35 (Hazard Ratio [HR] 1.24 95%-Confidence Interval [CI] 1.14-1.36), Asian race (HR 1.24, CI 1.13-1.37), and tube thoracostomy (HR 1.2, CI 1.15-1.31). Mechancial pleurodesis (HR 0.37 CI 0.31-0.45) was superior to chemical pleurodesis (HR 0.71 CI 0.58-0.86) in reducing recurrence risk.

Conclusions: The risk of recurrent pneumothorax is greatest in patients age <35, Asians, and those requiring a tube thoracostomy. The risks of operative intervention should be balanced against patient risk for recurrence.