Trends in pneumothorax mortality in England (2004-2023): a population-based observational study.

BACKGROUND: Monitoring pneumothorax mortality trends helps quantify disease burden, identify high-risk groups, assess guideline impacts, and inform resource planning. This study examined spontaneous pneumothorax (SP) mortality trends in England. METHODS: We conducted a population-based observational study using linked national death registrations from the Office for National Statistics and Hospital Episode Statistics Admitted Patient Care (HES-APC) from 1st January 2004 to 31st December 2023. SP-related mortality was any mention of spontaneous pneumothorax on the death certificate; SP-specific was spontaneous pneumothorax as the underlying cause. In this study, primary and secondary spontaneous pneumothorax follow a modified definition from conventional guidelines and included patients (of any age) with and without documented chronic lung disease respectively. We classified in-hospital deaths as primary or secondary spontaneous pneumothorax using chronic lung disease recorded on the death certificate or in linked HES-APC records. FINDINGS: We identified 6,442 spontaneous pneumothorax-related deaths, including 5,055 in-hospital deaths. Among in-hospital deaths, 4,093 (81.0%) had chronic lung disease and 962 (19.0%) had no recorded lung disease. From 2004 to 2019, the mean annual spontaneous pneumothorax-related mortality rate was 6.4 per 1,000,000 and declined year on year (IRR 0.986, 95% CI 0.980-0.991). Rates increased after 2019 and peaked at 8.1 per 1,000,000 in 2021, then fell to 6.9 per 1,000,000 in 2023. The excess in 2021 was largely COVID-related (2.3 per 1,000,000). In 2021, non-COVID mortality was similar to pre-2020 levels. From 2017 to 2023, spontaneous pneumothorax was certified as the underlying cause in 7.9% (215/2,735) of spontaneous pneumothorax-related death certificates, whereas it appeared in Part I (the section documenting the causal sequence of conditions leading directly to death) in 64% (1,750/2,735). INTERPRETATION: In 2020, the COVID-19 pandemic interrupted a long-term reduction in spontaneous pneumothorax mortality. Relying solely on underlying cause of death substantially underestimates pneumothorax's overall contribution to mortality in England. Patients and clinicians should be aware that pneumothorax is not an entirely benign disease and remains a significant cause of mortality in individuals with and without underlying lung disease, particularly in those over 65 years of age. FUNDING: This work was supported by the NIHR Oxford Biomedical Research Centre and by Health Data Research UK.