Ten-year patient survival on maintenance haemodialysis: association with treatment time and dialysis dose

BACKGROUND: Analyses of national registry-based datasets have demonstrated the association of longer haemodialysis treatment times with lowered mortality risk. METHODS: We performed a prospective cohort study of 451 incident haemodialysis patients and examined the effect of targeting higher dialysis dose with extended treatment time, on 10-year patient outcomes. RESULTS: Mean treatment time (TT) was 233 ± 22.8 minutes (median 235, range 180-296). Overall patient survival was 95% at 1 year, 75% at 3 years, 56% at 5 years and 25% at 10 years. Increasing TT was associated with incremental 10-year patient survival (TT >/=241 minutes 39.7%, TT 226-240 minutes 19.6% and TT </=225 minutes 14.7%; p<0.001). Single pool Kt/V and TT were strong independent predictors of patient survival in Cox multivariate analysis (p<0.0001). At 10 years, each 0.1-unit increase in spKt/V and 20-minute increase in TT were associated with a 20% and 32% decrease in the relative risk of death, respectively. Survival benefits of higher dialysis dose and longer TT were cumulative, with highest survival exhibited by patients achieving both Kt/V >1.6 and TT >/=241 minutes, and lowest survival exhibited by patients receiving Kt/V <1.2 and TT </=225 minutes. CONCLUSION: Extended treatment times are associated with higher patient survival irrespective of dialysis dose. Further study of extended treatment time and effect on patient outcomes is needed.