A Trial of Extending Hemodialysis Hours and Quality of Life

Abstract

The relationship between increased hemodialysis hours and patient outcomes remains unclear. We randomized (1:1) 200 adult recipients of standard maintenance hemodialysis from in-center and home-based hemodialysis programs to extended weekly (≥24 hours) or standard (target 12-15 hours, maximum 18 hours) hemodialysis hours for 12 months. The primary outcome was change in quality of life from baseline assessed by the EuroQol 5 dimension instrument (3 level) (EQ-5D). Secondary outcomes included medication usage, clinical laboratory values, vascular access events, and change in left ventricular mass index. At 12 months, median weekly hemodialysis hours were 24.0 (interquartile range, 23.6-24.0) and 12.0 (interquartile range, 12.0-16.0) in the extended and standard groups, respectively. Change in EQ-5D score at study end did not differ between groups (mean difference, 0.04 [95% confidence interval, -0.03 to 0.11]; P=0.29). Extended hours were associated with lower phosphate and potassium levels and higher hemoglobin levels. Blood pressure (BP) did not differ between groups at study end. Extended hours were associated with fewer BP-lowering agents and phosphate-binding medications, but were not associated with erythropoietin dosing. In a substudy with 95 patients, we detected no difference between groups in left ventricular mass index (mean difference, -6.0 [95% confidence interval, -14.8 to 2.7] g/m²; P=0.18). Five deaths occurred in the extended group and two in the standard group (P=0.44); two participants in each group withdrew consent. Similar numbers of patients experienced vascular access events in the two groups. Thus, extending weekly hemodialysis hours did not alter overall EQ-5D quality of life score, but was associated with improvement in some laboratory parameters and reductions in medication burden. (Clinicaltrials.gov identifier: NCT00649298).

Keywords: extended dialysis; hemodialysis; left ventricular hypertrophy; quality of life; randomized controlled trials.

Figure 1.

Participant flow through the study.

Figure 2.

Total weekly dialysis hours at each visit in participants randomized to standard or extended weekly dialysis hours. The figure depicts the weekly hours at each visit according to randomization, with the size of the circles being proportional to the number of participants practicing the particular number of hours. * indicates the percentage of participants attending the study visit who were fully or partially adherent to the randomized allocation. Partially adherent was defined as receiving between 18 and 24 hours of weekly dialysis (i.e., more than the definition for standard hours but less than the definition for extended hours). FU, follow-up.

Figure 3.

Change in quality of life from study beginning to end was comparable for the extended and standard dialysis hours groups. The mean change in EQ-5D score is presented for each group firstly as a scatter plot depicting the individual change for each participant and as a box plot representing the median (line), interquartiles (box), and 10th and 90th percentiles (whiskers) of change. Positive numbers indicate EQ-5D score was higher at the end of the study than the beginning.

Figure 4.

The impact of extended dialysis hours on the change in quality of life from study beginning to end was comparable for prespecified subgroups defined by region, dialysis location, and time on dialysis. The figure shows the effect of extended dialysis hours on the primary end point of change in EQ-5D quality of life at 12 months according to prespecified subgroups defined by region, dialysis location, and months on dialysis at commencement of the study.

Figure 5.

Both PCS and MCS significantly improved with extended hours when all follow-up visits were assessed. Effect of extended hours on (A) physical and (B) mental quality of life at each study visit. Figures represent the mean (box) and SD (whiskers) score at each time point for participants randomized to extended and standard weekly hemodialysis hours. The inserted text provides the estimate of the mean intervention effect over all follow-up visits, adjusted for baseline, with positive values favoring the extended dialysis group.