Survival of patients who opt for dialysis versus conservative care: a systematic review and meta-analysis

Abstract

Background: Non-dialytic conservative care (CC) has been proposed as a treatment option for patients with kidney failure. This systematic review and meta-analysis aims at comparing survival outcomes between dialysis and CC in studies where patients made an explicit treatment choice.

Methods: Five databases were systematically searched from origin through 25 February 2021 for studies comparing survival outcomes among patients choosing dialysis versus CC. Adjusted and unadjusted survival rates were extracted and meta-analysis performed where applicable. Risk of bias analysis was performed according to the Cochrane Risk Of Bias In Non-randomized Studies of Interventions.

Results: A total of 22 cohort studies were included covering 21 344 patients. Most studies were prone to selection bias and confounding. Patients opting for dialysis were generally younger and had fewer comorbid conditions, fewer functional impairments and less frailty than patients who chose CC. The unadjusted median survival from treatment decision or an estimated glomerular filtration rate <15 mL/min/1.73 m2 ranged from 20 and 67 months for dialysis and 6 and 31 months for CC. Meta-analysis of 12 studies that provided adjusted hazard ratios (HRs) for mortality showed a pooled adjusted HR of 0.47 (95% confidence interval 0.39-0.57) for patients choosing dialysis compared with CC. In subgroups of patients with older age or severe comorbidities, the reduction of mortality risk remained statistically significant, although analyses were unadjusted.

Conclusions: Patients opting for dialysis have an overall lower mortality risk compared with patients opting for CC. However, a high risk of bias and heterogeneous reporting preclude definitive conclusions and results cannot be translated to an individual level.

Keywords: conservative care; dialysis; end-stage kidney disease; mortality; systematic review.

Graphical Abstract

FIGURE 1:

Visualization of selection bias. In this figure, the course of eGRF also reflects the course of time.

FIGURE 2:

Study inclusion and exclusion flowchart. ^aExplanation of reasons for exclusion: no treatment decision yet includes patients with advanced CKD who did not, or did not have to, decide on preferred treatment yet (commonly referred to as ‘pre-dialysis patients’ or ‘non-dialysis dependent CKD patients’), including five studies discussed with the authors to clarify their patient groups (Supplementary data, Table S2). Mix of patient groups means a mix of different patient categories into one patient group without subgroup analyses (e.g. mix of patients who have not made a decision yet and patients who chose conservative care). No original research, e.g. reviews, opinion papers or study protocols.

FIGURE 3:

The risk of bias as assessed with the ROBINS-I for all 22 included studies.

FIGURE 4:

Meta-analysis of (A) adjusted survival and (B) unadjusted 1-year survival comparing choice of dialysis with choice of conservative care. *Considered as the best studies in addressing confounding and selection bias. ^†These studies used a different starting point for the dialysis (initiation of dialysis) versus the CC group (eGFR <15 mL/min/1.73 m²)

FIGURE 5:

Unadjusted median survival outcomes, grouped per reference point of survival analysis. The minimum age for inclusion in each study is shown if applicable. Note that as these data are unadjusted, (sometimes large) imbalances between the dialysis and conservative care groups may exist, including older age, greater presence of severe comorbidity, more frailty, worse functional performance and worse cognitive performance in the group opting for CC. Please refer to Table 2 and Supplementary data, Table S4 for more details.

FIGURE 6:

Unadjusted 2-year RRs for patients with severe comorbidity.