Prevalence of anemia and its impact on mortality and hospitalization rate in predialysis patients

Abstract

Background/aim: Anemia is associated with increased mortality and morbidity in both early and very late stages of chronic kidney disease (CKD). The aim of this study was to assess whether anemia is a risk factor for mortality or hospitalization in CKD stage 4-5 predialysis patients not yet on dialysis.

Methods: Incident predialysis patients were included between 1999 and 2001 and followed until January 2008 or death. Anemia was defined as mean hemoglobin (Hb) < or =11 g/dl in the 3 months before the start of predialysis. Associations were assessed by Cox regression, linear and logistic regression analysis.

Results: A total of 472 patients were included (median follow-up time 12 months, 11% died, 79% started dialysis). Mean Hb was 11.2 g/dl (minimum 7.6, maximum 16.9). Forty-eight percent of patients had anemia at the start of predialysis care. The adjusted mortality risk (hazard ratio, 95% confidence interval) for anemic compared to nonanemic patients was 1.92 (1.04, 3.52). Anemia tended to be related to all-cause but not to non-dialysis-related hospitalization risk.

Conclusion: At the start of predialysis care, 48% of patients had anemia. Anemia as defined in guideline targets is not associated with an increase in hospitalizations not related to renal replacement therapy, but is likely an important risk factor for mortality in predialysis patients.