Pruritus in Hemodialysis Patients: Longitudinal Associations With Clinical and Patient-Reported Outcomes

Rationale & Objective: Cross-sectional studies have reported an association of chronic kidney disease-associated pruritus (CKD-aP) with adverse clinical events and patient-reported outcomes (PROs). We studied the longitudinal associations between changes in CKD-aP and clinical outcomes among patients receiving maintenance hemodialysis. Study Design: Prospective cohort study. Setting & Participants: 7,976 hemodialysis recipients across 21 countries in phases 4-6 (2009-2018) of the Dialysis Outcomes and Practice Patterns Study (DOPPS) who had 2 CKD-aP assessments approximately 12 months apart. Exposures: Exposure status was based on the assessment of pruritis initially and again approxi-mately 1 year later. Four groups were identified, including those with moderate or more severe pruritis only at the initial assessment (resolved), only at the second assessment (incident), at neither assessment (absent), or at both assess-ments (persistent). Outcomes: Laboratory values and PROs ascer-tained at the initial assessment of pruritis and 1 year later. Analytical Approach: Linear mixed model to investigate changes in laboratory values and PROs over the 1-year study period across the 4 exposure groups. Results: 51% of patients had moderate to severe CKD-aP symptoms at either assessment (22% at both). The prevalences of depression, restless sleep, and feeling drained increased over the study period (+13%, +10%, and +14%, respectively) among patients with incident pruritus and decreased (-5%, -8%, and -12%, respectively) among patients with resolved pruritus. Minimal changes in PROs over time were observed for the absent and persistent groups. Changes over time in laboratory values (phosphorus, Kt/V) were not detected for either of these groups. Compared with patients with absent CKD-aP, the adjusted HRs for patients with persistent CKD-aP were 1.29 (95% CI, 1.0 9-1.53) for all-cause mortality, 1.17 (1.07-1.28) for all-cause hospitalization, and 1.48 (1.26-1.74) for cardiovascular events. Limitations: No interim evaluation of CKD-aP symptoms between the 2 assessments; potential selection bias from patients who died or were otherwise lost to follow-up before the second assessment. Conclusions: CKD-aP symptoms are chronic, and these findings highlight the potential value of repeated assessment of this symptom using standardized approaches. Future research should systematically investigate potential cau-ses of CKD-aP and options for its effective treatment.