Prognostic performance of the RAPID risk stratification score in pleural infection: a systematic review and meta-analysis

Introduction In pleural infection the RAPID score, which incorporates renal function, age, pleural fluid purulence, infection source and serum albumin, is a validated risk stratification tool for prediction of mortality. However, its predictive ability in wider patient populations has not been investigated. Methods We searched PubMed, Ovid Embase and the Cochrane Central Register, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies in adults with pleural infection recording the baseline RAPID score and reporting mortality and other clinical outcomes were included. The primary outcome was all-cause 3-month mortality by RAPID risk category. Secondary outcomes were hospital length of stay, intrapleural enzyme therapy (IET) use and surgical intervention. Results Nine studies comprising 2839 patients were included. The RAPID score demonstrated strong discriminatory ability for all-cause 3-month mortality, with pooled mortality rates of 32.0% (95% CI 26.0% to 39.0%; I2=50.9%) in high-risk, 13.0% (95% CI 10.0% to 16.0%; I2=48.6%) in medium-risk and 4.0% (95% CI 2.0% to 6.0%; I2=32.3%) in low-risk groups. The high-risk group was associated with a longer hospital stay with the mean difference of 7.7 days (95% CI 4.96 to 10.59; p=0.282; I2=20.8%) compared with the low-risk group. No significant difference was demonstrated in use of IET between the high-risk and low-risk groups. Surgical intervention rates were numerically higher in the high-risk compared with low-risk groups; however, this difference was not statistically significant (OR 1.55, 95% CI 0.21 to 11.50; p=0.670). Discussion This meta-analysis confirms the prognostic performance of the RAPID score in predicting all-cause 3-month mortality across diverse populations. Further studies are now needed to assess its utility in guiding treatment decisions and altering clinical outcomes. PROSPERO registration number CRD42023470720.