A prospective national cohort study of patients with secondary spontaneous pneumothorax assessing the impact of frailty at diagnosis on mortality and admission to hospital.

Aim: Secondary spontaneous pneumothorax (SSP) most commonly occurs in older patients with known underlying lung disease. Many are frail, but the effect of frailty on outcomes has not been explored previously. This study aims to evaluate the association between frailty and healthcare outcomes in patients with SSP. Methods: Patients with SSP were identified from the national Secure Anonymised Information Linkage databank. Frailty status was assessed using the electronic frailty index. The primary outcome was time from diagnosis to all-cause mortality. Secondary outcomes included time from diagnosis to disease-specific mortality and admission to hospital. Data were analysed using a multilevel Cox proportional hazards regression model, adjusted for age, sex, Welsh Index of Multiple Deprivation, smoking status and comorbidities. Results: Our search identified 3535 individuals diagnosed with SSP between 1 January 2005 and 1 March 2023. By the end of the study, 2102 (59.6%) participants had died with a median follow-up of 683 days (interquartile range 159-1650 days). There was an increasing risk of mortality for those with mild (adjusted hazard ratio (aHR) 1.24, 95% CI 1.10-1.39), moderate (aHR 1.46, 95% CI 1.25-1.70) and severe (aHR 1.83, 95% CI 1.43-2.32) frailty compared to fit individuals. There was also an association between frailty and time to first all-cause hospitalisation, but not disease-specific hospitalisation. Conclusions: Frailty status at diagnosis was an independent predictor of all-cause mortality in patients with SSP. This demonstrates the importance of assessing frailty status to enable clinicians to provide optimised care and make informed decisions about management of patients with SSP.