S44 Risk factors for recurrence of primary spontaneous pneumothorax: analysis from the RAMPP trial

Introduction and Objectives Primary Spontaneous Pneumothorax (PSP) is a common condition with a high recurrence rate (28–33%).1, 2, 3 Current guidelines suggest referral for recurrence prevention surgery after the second episode. Identifying patients at greater risk of recurrence would allow a more stratified approach. A number of factors have been proposed previously, but none have been robustly proven. This study used a large prospectively collected dataset from the RAMPP (Randomised Ambulatory Management of Primary Pneumothorax) Trial1 in the UK to assess risk factors for pneumothorax recurrence up to 12 months. Methods The RAMPP dataset included 423 patients: 236 were managed actively (either ambulatory or standard care arms) and an observational cohort of 187 patients with small, minimally symptomatic pneumothoraces managed conservatively. A Cox proportional hazards model was used to assess risk of recurrence by the following variables: patient age, sex, size of initial pneumothorax, smoking history (tobacco and marijuana), personal history of prior pneumothorax history, family history and treatments given. Results The overall recurrence rate at 12 months was 20.6% (87/423) with a significantly lower rate in the conservatively-managed observational cohort (22/187, 11.8%), than the ambulatory and standard care arms (28/117, 23.9%, and 37/119, 31.1%, respectively) (p Conclusion Patients with small, minimally symptomatic pneumothorax have a low recurrence rate (11.8%). Previous history of pneumothorax is associated with increased risk of recurrence. Further work is required to identify other risk factors to determine who may benefit from early recurrence prevention procedures. References Hallifax RJ. Lancet 2020;396:39–49. Hallifax RJ. JAMA 2018;320(14):1471–1480. Bobbio A. Thorax 2015;70:653–58.