Prevalence, severity, and determinants of CKD-associated pruritus in a Swiss hemodialysis population with widespread use of hemodiafiltration: a cross-sectional study

Chronic Kidney Disease Associated-Pruritus (CKD-aP) is frequent among hemodialysis patients. Its associations with hemodiafiltration or conventional hemodialysis and clinical characteristics are inconsistent in observational studies. This study aimed to assess the prevalence, severity and factors associated with CKD-aP among patients on hemodialysis in the French-speaking part of Switzerland, where hemodiafiltration is widely used. A cross-sectional design was used. Adults on hemodialysis for ≥ 6 months and free of cognitive impairment were recruited from 15 dialysis centers. A research nurse collected sociodemographic, clinical, laboratory data and assessed CKD-aP using the Visual Analogue Scale (VAS) and Verbal Rating Scale (VRS). A multilevel mixed-effects model with maximum likelihood estimation was performed to investigate associations. A total of 413 participants, mean age was 69.68 years (SD 13.52), were included; 66% were men, 73% on hemodiafiltration. CKD-aP prevalence was 25%. VAS average itch score of participants with CKD-aP was 4.74 ± 1.99, versus 6.62 ± 2.18 for the worst intensity itch. According to VRS, most participants with CKD-aP suffered moderate (61.4%) to severe (22%) itch within the past 24 h. Higher phosphorus levels were significantly associated with increased CKD-aP severity, but not prevalence. Depression, smoking, and polypharmacy were associated with increased CKD-aP severity, whereas hemodialysis modality, volume substitution, filter or access type were not. Despite high dialysis standards, CKD-aP remains a frequent symptom in Switzerland. Depression is associated with CKD-aP and its severity while hemodialysis modality is not. These results suggest that effective management of CKD-aP requires not only optimal dialysis prescription but also a holistic approach. Registered at ClinicalTrials.gov (NCT05524467) on 10.06.2022.