RESUMO
BACKGROUND AND OBJECTIVE: To examine whether red cell distribution width (RDW) performs as a mortality predictor after hospital discharge in patients over 70 years of age and if its prognostic power is superior to other laboratory parameters. PATIENTS AND METHODS: Longitudinal and prospective study of 426 patients admitted to the Internal Medicine Department who survived hospitalization. Sociodemographic and comorbidity factors, functional and cognitive status as well as disease parameters causing admission (diagnosis, analytical parameters, length of stay) were collected. Patients were followed for one year by telephone interview and data were collected regarding vital status and, if appropriate, death date. RDW effect on mortality was assessed using logistic regression and prognostic capability by the area under the ROC curve. RESULTS: Each percentage point rise in RDW was associated with increased mortality at one year with an odds ratio of 1.19 (95% confidence interval [95% CI] 1.08 to 1.31). Mortality in each tertile of RDW was 15.6% in the lowest, 21.5% in the middle and 30.5% in the highest. A clinical model supplemented with RDW improved mortality predictive ability assessed by ROC curve. Net reclassification improvement of the prediction rule was 1.71% (95% CI 0.07 to 3.35) p=0.04. CONCLUSION: This study provides new evidence of the RDW association with mortality in a cohort of elderly patients who survived hospitalization. RDW was the only laboratory parameter that improved the one-year prognostic mortality ability.