Survival with three-times weekly in-center nocturnal versus conventional hemodialysis

Abstract

Whether the duration of hemodialysis treatments improves outcomes remains controversial. Here, we evaluated survival and clinical changes associated with converting from conventional hemodialysis (mean=3.75 h/treatment) to in-center nocturnal hemodialysis (mean=7.85 h/treatment). All 959 consecutive patients who initiated nocturnal hemodialysis for the first time in 77 Fresenius Medical Care facilities during 2006 and 2007 were eligible. We used Cox models to compare risk for mortality during 2 years of follow-up in a 1:3 propensity score-matched cohort of 746 nocturnal and 2062 control patients on conventional hemodialysis. Two-year mortality was 19% among nocturnal hemodialysis patients compared with 27% among conventional patients. Nocturnal hemodialysis associated with a 25% reduction in the risk for death after adjustment for age, body mass index, and dialysis vintage (hazard ratio=0.75, 95% confidence interval=0.61-0.91, P=0.004). With respect to clinical features, interdialytic weight gain, albumin, hemoglobin, dialysis dose, and calcium increased on nocturnal therapy, whereas postdialysis weight, predialysis systolic blood pressure, ultrafiltration rate, phosphorus, and white blood cell count declined (all P<0.001). In summary, notwithstanding the possibility of residual selection bias, conversion to treatment with nocturnal hemodialysis associates with favorable clinical features, laboratory biomarkers, and improved survival compared with propensity score-matched controls. The potential impact of extended treatment time on clinical outcomes while maintaining a three times per week hemodialysis schedule requires evaluation in future clinical trials.

Figures

Figure 1.

Enrollment algorithm. Patient flow into the study.

Figure 2.

Enhanced INHD survival. Kaplan–Meier 2-year survival curves comparing patients on INHD (broken line) with patients on CHD (solid line).

Figure 3.

Enhanced adjusted INHD survival. Results from Cox proportional hazard models comparing time to death from patients treated by INHD with patients on CHD.

Figure 4.

Improved clinical features on INHD. Changes in (A) dialysis dose, (B) ultrafiltration rate, (C) postdialysis weight, (D) predialysis systolic blood pressure, (E) interdialytic weight gain, and (F) intradialytic weight loss associated with conversion from CHD to INHD from baseline (period 1), first 90 days (period 2), and days 91–180 (period 3) along with period prevalent propensity score-matched controls that were treated solely with CHD. (INHD: n=435; CHD: n=1219).

Figure 5.

Improved biomarkers on INHD. Laboratory changes for (A) albumin, (B) hemoglobin, (C) phosphorus, (D) calcium, and (E) white blood cell count associated with conversion from CHD to INHD from baseline (period 1), first 90 days (period 2), and days 91–180 (period 3) along with period prevalent propensity score–matched controls that were treated solely with CHD. (INHD: n=435; CHD: n=1219).

Figure 6.

Long-term maintenance INHD therapy. INHD technique survival over 2 years.