A Clinical Score (RAPID) to Identify Those at Risk for Poor Outcome at Presentation in Patients With Pleural Infection

Pleural infection is associated with a high morbidity and mortality. Development of a validated clinical risk score at presentation to identify those at high risk of dying would enable patient triage and may help formulate early management strategies.A clinical risk score was derived based on data from patients entering the multicenter UK pleural infection trial (first Multicenter Intrapleural Sepsis Trial [MIST1], n=411). From 22 baseline clinical characteristics, model selection was undertaken to find variables predictive of poor clinical outcome. Outcomes were mortality at 3 months (primary), need for surgical intervention at 3 months, and time from randomization to discharge. The derived scoring system RAPID (renal, age, purulence, infection source, and dietary factors) was validated using patients enrolled in the subsequent MIST2 trial (n=191).Age, urea, albumin, hospital-acquired infection, and nonpurulence predicted poor outcome. Patients were stratified into low-risk (0-2), medium-risk (3-4), and high-risk (5-7) groups. Using the low-risk group as a reference, a RAPID score of 3 to 4 and >4 was associated with an OR of 24.4 (95% CI, 3.1-186.7; P=.002) and 192.4 (95% CI, 25.0-1480.4; P<.001), respectively, for death at 3 months. In the validation cohort (MIST2), a medium-risk RAPID score was nonsignificantly associated with mortality (OR, 3.2; 95% CI, 0.8-13.2; P=.11), and a high-risk score was associated with increased mortality (OR, 14.1; 95% CI, 3.5-56.8; P<.001). Hospitalization duration was associated with increasing RAPID score (score 0-2: median duration=7, interquartile range 6-13; score>5: median duration=15, interquartile range 9-28, P=.08).The RAPID score may permit risk stratification of patients with pleural infection at presentation.