Impact of incremental initiation of haemodialysis on mortality: a systematic review and meta-analysis

Background Incremental haemodialysis initiation entails lower sessional duration and/or frequency than the standard 4 h thrice-weekly approach. Dialysis dose is increased as residual kidney function (RKF) declines. This systematic review evaluates its safety, efficacy and cost-effectiveness. Methods We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library databases from inception to 27 February 2022. Eligible studies compared incremental haemodialysis (sessions either fewer than three times weekly or of duration <3.5 h) with standard treatment. The primary outcome was mortality. Secondary outcomes included treatment-emergent adverse events, loss of RKF, quality of life and cost effectiveness. The study protocol was prospectively registered. Risk of bias assessment used the Newcastle-Ottawa Scale and the revised Cochrane risk of bias tool, as appropriate. Meta-analyses were undertaken in Review Manager, Version 5.4. Results A total of 644 records were identified. Twenty-six met the inclusion criteria, including 22 cohort studies and two randomized controlled trials (RCTs). Sample size ranged from 48 to 50 596 participants (total 101 476). We found no mortality differences (hazard ratio = 0.99; 95% CI 0.80-1.24). Cohort studies suggested similar hospitalization rates though the two small RCTs suggested less hospitalization after incremental initiation (relative risk = 0.31; 95% CI 0.18-0.54). Data on other treatment-emergent adverse events and quality of life was limited. Observational studies suggested reduced loss of RKF in incremental haemodialysis. This was not supported by RCT data. Four studies reported reduced costs of incremental treatments. Conclusions Incremental initiation of haemodialysis does not confer greater risk of mortality compared with standard treatment. Hospitalization may be reduced and costs are lower.