C-reactive protein concentration as a predictor of intensive care unit readmission: a nested case-control study

The purpose of this study is to assess the ability of potential clinical predictors and inflammatory markers to predict intensive care unit (ICU) readmission during the same hospitalization.

A nested case-control study utilized prospectively collected de-identified data of a 22-bed multidisciplinary ICU in a university hospital.

There were 1,405 consecutive ICU admissions in 2004, and of these, 18 were regarded as ICU readmissions (1.3%). The destination and timing of ICU discharge, the Sequential Organ Failure Assessment scores, white cell counts, and fibrinogen concentrations at discharge were not associated with ICU readmission. C-reactive protein (CRP) concentration within 24 hours before ICU discharge was associated with ICU readmission (mean CRP concentrations of cases vs controls, 177.8 vs 56.5 mg/L, respectively; P < .0001). The results remained unchanged after adjustment with the propensity scores. The area under the receiver operating characteristic curve for the CRP concentrations to predict ICU readmission was 0.884 (95% confidence interval, 0.765-0.999; P < .0001). Patients readmitted to the ICU had a higher predicted mortality in their second ICU admission (34.9% vs 26.1%; P < .01) and a longer total hospital stay (33.3 vs 20.3 days; P < .003) than patients without ICU readmission.

A high CRP concentration within 24 hours before ICU discharge is associated with a higher risk of readmission to the ICU.