Abstract

Background: Scoring systems including CURB-65 and Pneumonia Severity Index (PSI) and novel or traditional biomarkers including procalcitonin (PCT) and c-reactive protein (CRP) are very significant for understanding the severity and prognosis in community-acquired pneumonia (CAP) patients, while prognostic items are useful for CAP prognostication and point-of-care decisions. The aim of this study was to investigate the usefulness of peripheral blood routine items in predicting ICU admission and 30-day mortality in CAP patients.

Methods: A retrospective study was conducted. All adult patients with a primary diagnosis of CAP were included and peripheral blood routine tests were evaluated. Univariate analysis and multivariate logistic regression analysis were used to explore association of risk factors with 30-day mortality among CAP patients. Receiver operating characteristic curves (ROC) were used to evaluate the sensitivity and specificity of peripheral blood routine items and compared with CURB-65 scores in predicting ICU admission and/or 30-day mortality.

Results: One hundred fifty patients were included and compared with non-ICU admission patients. There was a statistically significant difference in age, co-existing illness, RDW, WBC, and CURB-65 scores ranking in ICU admission patients (p < 0.05). In multivariate logistic regression analysis, we found RDW, WBC, and CURB-65 ≥ 3 scores increased the risk of 30-day mortality by 4.01, 1.65, and 3.43 times, respectively. The area under the curve (AUC) of ROC curves of RDW combined with WBC and CURB-65 was 0.786 (95% CI 0.701 to 0.876) and 0.836 (95% CI 0.764 to 0.908), respectively and the sensitivity was 84.0% and 60.0%, respectively, and the specificity 66.7% and 93.7%, respectively.

Conclusions: Elevated RDW and WBC increased mortality in adult CAP patients, RDW combined with WBC had a better sensitivity than CURB-65 scores in predicting ICU admission and/or mortality in CAP patients.