Nine cohort studies (one prospective; eight retrospective) were included in the review, with 1,734 participants (range 52 to 502). The length of follow-up ranged from four to 20 years.
The risk of death at five years was statistically significantly higher for patients who remained on a waiting list (treated with maintenance dialysis) than those who underwent kidney transplantation (RR 2.19, 95% CI 1.50 to 3.20). There was evidence of substantial heterogeneity between study results (Ι²=64.8%). Eight patients would need to be treated with kidney transplantation to prevent one extra death (NNT 8, 95% CI 5 to 11).
The proportion of patients in each treatment group dying from cardiovascular disease, infection and liver disease were presented.
The meta-regression analysis identified age as a potential source of heterogeneity. A subgroup analysis, in which patients aged 45 years or less were pooled, resulted in a non-statistically significant difference between treatment groups (RR 1.19, 95% CI 0.91 to 1.56), whilst patients aged over 45 years still had a statistically significantly higher risk of death in the waiting list group than the kidney transplantation group (RR 2.57, 95% CI 2.04 to 3.23). Pooling within age groups removed heterogeneity (Ι²=0% for both groups).
There was no evidence of publication bias suggested by the Egger test.