Health-related quality of life predicts outcomes but is not affected by peritoneal clearance: The ADEMEX trial

Background. We hypothesized that increasing small solute clearance in peritoneal dialysis (PD) would lead to improvements in patient health-related quality of life (HRQOL). Methods. Patients were randomized to a control group [standard 4×2L continuous ambulatory peritoneal dialysis (CAPD)] and an intervention group (CAPD with a target creatinine clearance ≥60L/week/1. 73m²). The Kidney Disease Quality of Life Short Form was obtained at baseline and at 6,12, and 24 months. Physical (PCS), mental (MCS), and kidney disease component summary (KDCS) scores were computed. Results. The two groups were comparable at baseline with respect to HRQOL. Baseline variables highly predictive of better QOL included absence of diabetes, younger age, higher starting GFR, and serum albumin. Baseline values of QOL were highly predictive of survival and hospitalizations. An unadjusted comparison revealed that patients in the intervention group had significantly higher PCS and KDCS scores at six months. However, there were no significant differences between the intervention and control patients at 12 or 24 months. When similar analyses were carried out adjusting for different patterns of patient dropout, there were no significant differences between the two groups at any time point in terms of PCS, MCS, and KDCS scores. Conclusion. We found no evidence of a long-term benefit in HRQOL of CAPD patients by increasing peritoneal small-solute clearances when HRQOL parameters were adjusted for patient dropout. Measures of HRQOL have a significant predictive value for patient survival and hospitalizations.