The association between frailty and survival in patients with pleural disease: a retrospective cohort study

There are currently no data on the relationship between frailty and mortality in pleural disease. Understanding the relationship between frailty and outcomes is increasingly important for clinicians to guide decisions regarding investigation and management. This study aims to explore the relationship between all-cause mortality and frailty status in patients with pleural disease.

In this retrospective analysis of a prospectively collected observational cohort study, outpatients presenting to the pleural service at a tertiary centre in Bristol, UK with a radiologically confirmed, undiagnosed pleural effusion underwent comprehensive assessment and were assigned a final diagnosis at 12 months. The modified frailty index (mFI) was calculated and participants classified as frail (mFI ≥ 0.4) or not frail (mFI ≤ 0.2).

676 participants were included from 3rd March 2008 to 29th December 2020. The median time to mortality was 490 days (IQR 161-1595). A positive association was found between 12-month mortality and frailty (aHR = 1.72, 95% CI 1.02-2.76, p = 0.025) and age ≥ 80 (aHR = 1.80, 95% CI 1.24-2.62, p = 0.002). Subgroup analyses found a stronger association between 12-month mortality and frailty in benign disease (aHR = 4.36, 95% CI 2.17-8.77, p < 0.0001) than in all pleural disease. Malignancy irrespective of frailty status was associated with an increase in all-cause mortality (aHR = 10.40, 95% CI 6.01-18.01, p < 0.0001).

This is the first study evaluating the relationship between frailty and outcomes in pleural disease. Our data demonstrates a strong association between frailty and 12-month mortality in this cohort. A malignant diagnosis is an independent predictor of 12-month mortality, irrespective of frailty status. Frailty was also strongly associated with 12-month mortality in patients with a benign underlying cause for their pleural disease. This has clinical relevance for pleural physicians; evaluating patients' frailty status and its impact on mortality can guide clinicians in assessing suitability for invasive investigation and management.

This study is registered with the Health Research Authority (REC reference 08/H0102/11) and the NIHR Portfolio (Study ID 8960).