Impact of erythropoiesis-stimulating agents on energy and physical function in nondialysis CKD patients with anemia: a systematic review.

Background: Previous analyses report the impact of erythropoiesis-stimulating agents (ESAs) on health-related quality of life across various populations. In this analysis, we review published studies and quantify the effect of ESA therapy on energy/fatigue and physical function in nondialysis patients with chronic kidney disease (CKD) related anemia.
Study Design: Systematic literature search to identify articles (1980-2008) that evaluated effects of ESAs on patient-reported energy and physical function.
Setting & Population: Nondialysis CKD patients with anemia enrolled in prospective trials.
Selection Criteria for Studies: Prospective studies measuring energy or physical function with both baseline and follow-up measurement.
Intervention: ESA treatment.
Outcomes: Improvements in energy and physical function assessed using effect size, a measure of treatment responsiveness.
Results: 14 studies were identified: 11 measured energy and 14 measured physical function. The 36-Item Short-Form Health Survey (SF-36) was the most common instrument used to report energy and physical function. Of 11 studies measuring energy, 2 were double-blind randomized placebo-controlled trials (RCTs), 5 were open-label RCTs, and 4 were single-arm open-label studies. Eight of 11 studies reported statistically significant improvements in energy. Effect size for energy ranged from small (0.24) to large (1.90) in ESA-treated groups and was moderate in each arm of the low- versus high-hemoglobin target RCTs. Of 14 studies measuring physical function, 2 were double-blind RCTs, 6 were open-label RCTs, and 6 were single-arm open-label studies. Ten of 14 studies reported statistically significant improvements in physical function. Effect size for physical function ranged from small (0.37) to large (2.38) in ESA-treated groups and was negligible to moderate in each arm of low- versus high-hemoglobin target studies.
Limitations: Findings and conclusions were limited by the available evidence.
Conclusion: RCTs and single-arm studies indicate that treatment of anemia with ESAs improves energy and physical function in nondialysis CKD patients.
(Copyright 2010 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)