Changes in Red Cell Distribution Width During Hospitalization for Community-Acquired Pneumonia: Clinical Characteristics and Prognostic Significance

Purpose We investigated outcomes of patients hospitalized with community-acquired pneumonia (CAP) according to the changes in red cell distribution width (RDW). Methods For 980 adults, clinical characteristics, outcomes during hospitalization for CAP (transfer to the intensive care unit, treatment with mechanical ventilation, prolonged hospital stay, and death), and all-cause mortality following discharge were compared: according to RDW changes versus stable RDW during hospitalization, and according to normal (≤14.7 %) versus high (>14.7 %) RDW values on admission/discharge. Results RDW changes ( n = 386) during hospitalization were associated with more severe clinical and laboratory characteristics than stable RDW ( n = 594). Changes in RDW strongly predicted poor in-hospital outcomes ( p < 0.001). The respective 30, 90-day, and total (median follow-up 54 months) mortality rates were significantly higher (9.8, 16.0 and 43.5 %) among patients with RDW changes, compared to 4.0, 7.6 and 30.5 % among those with stable RDW ( p < 0.001 for all comparisons). RDW changes, as well as high RDW (each 1 % increment) on admission and discharge, were powerful predictors of mortality (the respective relative risks 1.41, 1.13, and 1.15, and 95 % confidence intervals 1.13–1.74, 1.08–1.19, and 1.10–1.21). Conclusions RDW changes during hospitalization for CAP are common and associated with a severe clinical profile. Time-dependent RDW changes strongly predict poor in-hospital outcomes and increased short- and long-term mortality. Repeated RDW determinations during hospitalization for CAP may provide useful prognostic information.