Quality of life over time in dialysis: The Netherlands Cooperative Study on the Adequacy of Dialysis

Background. Information on the longitudinal quality of life (QL) of patients treated by different dialysis modalities is lacking. Therefore, we performed a prospective cohort study on the QL over time in hemodialysis (HD) and peritoneal dialysis (PD) patients. Methods. New chronic dialysis patients from 13 Dutch dialysis centers were consecutively included. The patients' self-assessment of QL was measured with the SF-36(TM) form at 3, 6, 12, and 18 months after the start of dialysis treatment. Results. Out of 230 patients who completed the QL questionnaire at least once, 139 patients stayed on their initial dialysis modality, 26 patients switched dialysis modality, 35 patients were transplanted, 28 patients died, and two patients had a recovery of renal function. The QL of patients who died during the study period was considerably worse at baseline and worsened at a faster rate than in the other patient groups. In patients who stayed on their initial dialysis modality, the physical QL decreased over time, whereas the mental QL tended to remain stable. After an adjustment for the initial value of QL and comorbidity, a consistently favorable effect of HD on physical QL over time was found compared with PD, whereas mental OL values remained similar. Parameters of adequacy of dialysis were not associated with QL over time. Conclusion. This prospective cohort study shows that physical OL over time in HD patients is better than in PD patients.