Pneumothorax is a common pathology. Primary spontaneous pneumothorax (PSP) conventionally refers to patients with no underlying lung disease, while those with established lung pathology are classified as secondary spontaneous pneumothorax (SSP). Commonly quoted estimates of incidence of spontaneous pneumothoraces are based on studies that are often many years old and from single centres 45 years ago in the USA1 and 30 years ago in Sweden:2 with a reported overall incidence of 18–24 per 100 000 cases per annum for men and 1.2–6 per 100 000 for women and that of PSP as 7.4–18 cases (age-adjusted incidence) and 1.2–6 cases per 100 000 population per year for men and women, respectively.1 2 More recently, Gupta et al3 published the largest epide...