Background: Concerns are present on the limited value of renal function alone in defining the optimal moment to start dialysis. Disease-related symptoms and health-related quality of life (HRQOL) may have additional clinical value in defining this moment, but little is known about how these parameters change during pre-dialysis care. The aims of our study were to describe the course of symptoms and HRQOL during pre-dialysis care and to investigate their association with poor health outcomes.
Methods: In the prospective PREPARE-2 cohort, incident patients starting specialized pre-dialysis care were included when referred to one of the 25 participating Dutch outpatient clinics (2004-2011). In the present analysis, 436 patients with data available on symptoms and HRQOL were included. Clinical data, symptoms (revised illness perception questionnaire), and HRQOL (short form-36 questionnaire; physical and mental summary score) were collected every 6-month interval. A time-dependent Cox proportional hazard model was used to associate symptoms and HRQOL with the combined poor health outcome (i.e. starting dialysis, receiving a kidney transplant, and death).
Results: All symptoms increased, especially fatigue and loss of strength, and both the physical and mental summary score decreased over time, with the most pronounced change during the last 6-12 months of follow-up. Furthermore, each additional symptom (adjusted HR 1.04 (95% CI, 1.00-1.09)) and each 3-point lower physical and mental summary score (adjusted HR 1.04 (1.02-1.06) and 1.04 (1.02-1.06) respectively) were associated with a higher risk of reaching the combined poor health outcome within the subsequent 6 months.
Conclusions: The number of symptoms increased and both the physical and mental HRQOL score decreased during pre-dialysis care and these changes were associated with starting dialysis, receiving a kidney transplant, and death. These results may indicate that symptoms and HRQOL are good markers for the medical condition and disease stage of pre-dialysis patients.