Intensive hemodialysis associates with improved survival compared with conventional hemodialysis

Abstract

Patients undergoing conventional maintenance hemodialysis typically receive three sessions per week, each lasting 2.5-5.5 hours. Recently, the use of more intensive hemodialysis (>5.5 hours, three to seven times per week) has increased, but the effects of these regimens on survival are uncertain. We conducted a retrospective cohort study to examine whether intensive hemodialysis associates with better survival than conventional hemodialysis. We identified 420 patients in the International Quotidian Dialysis Registry who received intensive home hemodialysis in France, the United States, and Canada between January 2000 and August 2010. We matched 338 of these patients to 1388 patients in the Dialysis Outcomes and Practice Patterns Study who received in-center conventional hemodialysis during the same time period by country, ESRD duration, and propensity score. The intensive hemodialysis group received a mean (SD) 4.8 (1.1) sessions per week with a mean treatment time of 7.4 (0.87) hours per session; the conventional group received three sessions per week with a mean treatment time of 3.9 (0.32) hours per session. During 3008 patient-years of follow-up, 45 (13%) of 338 patients receiving intensive hemodialysis died compared with 293 (21%) of 1388 patients receiving conventional hemodialysis (6.1 versus 10.5 deaths per 100 person-years; hazard ratio, 0.55 [95% confidence interval, 0.34-0.87]). The strength and direction of the observed association between intensive hemodialysis and improved survival were consistent across all prespecified subgroups and sensitivity analyses. In conclusion, there is a strong association between intensive home hemodialysis and improved survival, but whether this relationship is causal remains unknown.

Figure 1.

Study cohort assembly showing eligible patients and exclusions. Because there were no patients with dementia receiving intensive dialysis, patients with dementia were excluded from the conventional dialysis group. HD, hemodialysis. ^†Patients missing data for any of the following comorbid conditions were excluded: diabetes, myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, or cancer (hematologic and solid organ malignancies combined into a single aggregate variable).

Figure 2.

Kaplan–Meier plot for intensive and conventional hemodialysis. Two-sided P=0.002 by log-rank test, stratified by matched set and country. HD, hemodialysis.

Figure 3.

Subgroup analyses for matched cohorts (unadjusted). P values for interactions are based on z tests. IHD, intensive hemodialysis; CHD, conventional hemodialysis; MI, myocardial infarction; CHF, congestive heart failure. *Median age at cohort entry is 52 years. **Median duration of ESRD at cohort entry is 3.5 years.