Platelet distribution width: a novel prognostic marker in an internal medicine ward

Background: Platelet distribution width (PDW) has demonstrated clinical significance in populations with specific disorders; its prognostic significance in internal medicine wards has not been investigated. Methods: Demographic, clinical and laboratory data were collected prospectively for 1036 internal medicine inpatients. The primary outcome was 90-day mortality, secondary outcomes were: treatment with mechanical ventilation, prolonged hospital stay, in-hospital death, and all-cause mortality following discharge. Data were assessed according to PDW values on admission <= 16.7% (group A) and >16.7% (group B). Results: Compared to group A patients (n = 273), group B patients (n = 763) were more likely to be older, admitted for cardio-cerebrovascular disorder, to present with comorbidities, to be mechanically ventilated, to have prolonged hospital stay and to die during the current hospitalization. The respective 90-day and total (median follow-up of 5 months) mortality rates were significantly higher in group B (13.2% and 16.3%) than in group A (6.6% and 9.5%), P < 0.01. On multivariate analysis, higher PDW values on admission predicted 90-day mortality and shortened survival (relative risks 1.58 and 1.26; 95% confidence intervals 0.89 - 2.78 and 0.97-1.64, respectively). Conclusion: Higher PDW values on admission to internal medicine wards are associated with a more severe clinical profile and increased risk of 90-day mortality.