Comparative Effectiveness of Iron and Erythropoiesis-Stimulating Agent Dosing on Health-Related Quality of Life in Patients Receiving Hemodialysis

Abstract

Background: The potential effects of iron-dosing strategies and erythropoiesis-stimulating agents (ESAs) on health-related quality of life (HRQoL) in the dialysis population are unclear. We examined the independent associations of bolus versus maintenance iron dosing and high versus low ESA dosing on HRQoL.

Study design: Retrospective cohort design.

Setting & participants: Clinical data (2008-2010) from a large dialysis organization merged with data from the US Renal Data System. 13,039 patients receiving center-based hemodialysis were included.

Predictor: Iron and ESA dosing were assessed during 1-month (n=14,901) and 2-week (n=15,296) exposure periods.

Outcomes: HRQoL was measured by the Kidney Disease Quality of Life (KDQOL) instrument (0-100 scale) during a 3-month follow-up period.

Measurements: Generalized linear mixed models, adjusting for several covariates, were used to estimate associations between iron and ESA dosing and HRQoL overall and for clinically relevant subgroups.

Results: For the 1-month exposure period, patients with lower baseline hemoglobin levels who received higher ESA dosing had higher physical health and kidney disease symptom scores (by 2.4 [95% CI, 0.6-4.2] and 5.6 [95% CI, 2.8-8.4] points, respectively) in follow-up than patients who received lower ESA dosing. For the 2-week exposure period, patients with low baseline hemoglobin levels who received bolus dosing had higher mental health scores (by 1.9 [95% CI, 0.0-3.8] points) in follow-up. Within the low-baseline-hemoglobin subgroup, individuals with a catheter or dialysis vintage less than 1 year who received higher ESA dosing had higher HRQoL scores in follow-up (by 5.0-9.9 points) and individuals with low baseline transferrin saturations who received bolus dosing had higher HRQoL scores in follow-up (by 2.6-5.8 points).

Limitations: Observational design; short duration of observation.

Conclusions: For individuals with low baseline hemoglobin levels, higher ESA dosing and bolus iron dosing were associated with slightly higher HRQoL scores in follow-up. These differences became more pronounced and clinically relevant for specific subgroups.

Keywords: Health-related quality of life (HRQoL); anemia; bolus dosing; chronic kidney disease (CKD); dosing pattern; end-stage renal disease (ESRD); epoetin alfa; erythropoiesis-stimulating agent (ESA); hemodialysis (HD); hemoglobin; intravenous iron; maintenance dosing; transferrin saturation (TSAT).