Association of early versus late initiation of dialysis with mortality: systematic review and meta-analysis

Background/aims: The association of the timing of dialysis initiation with mortality is controversial. We conducted a meta-analysis to determine the relationship between the risk of death and early initiation of dialysis, when the patient has a greater estimated glomerular filtration rate (eGFR).

Methods: Prospective and retrospective cohort studies that independently measured the effect of early vs. late initiation of dialysis on risk of death were identified by review of several databases. Odds ratios (ORs) were estimated by comparison of the highest and lowest quartiles and combined by a random-effects model.

Results: 15 studies (1,285,747 patients) met the inclusion criteria. Summary estimates indicated that early start of dialysis was associated with increased risk of mortality (OR = 1.33, 95% confidence interval (CI): 1.18-1.49, p < 0.00001). Subgroup analysis indicated that early starters were 6.61 years older (p < 0.00001) and more likely to have diabetes (OR = 2.23, 95% CI: 1.83-2.71, p < 0.00001) than late starters. Analysis of pooled results of early and late starters indicated that older age (OR = 1.18, 95% CI: 1.05-1.33, p = 0.006), diabetes (OR = 1.61, 95% CI: 1.38-1.87, p < 0.00001), and high comorbidity index score (OR = 2.38, 95% CI: 1.75-3.25, p < 0.00001) were strongly associated with increased risk of death.

Conclusion: Our meta-analysis indicates that early initiation of dialysis (at higher eGFR) was associated with an increased risk of death. Older age, greater likelihood of diabetes, and the presence of severe comorbid disease(s) partly explain this effect.