Prevalence and Severity of Pruritus in Patients on Hemodialysis: A Cross-Sectional Study.

Background: Chronic kidney disease-associated pruritus (CKD-aP) is a distressing symptom associated with dialysis that negatively affects quality of life. Chronic kidney disease-associated pruritus is under-recognized due to a lack of clinical attention and symptom screening.

Objective: Assess the prevalence and severity of CKD-aP in a regional hemodialysis program.

Design: Cross-sectional study.

Setting and patients: All outpatients receiving in-center hemodialysis at the Kingston Health Sciences Centre.

Measurements: Patients were asked to complete the Worst Itching Intensity Numerical Scale (WI-NRS), with moderate-to-severe pruritus classified as a score greater than 4, and the Self-Assessed Disease Severity (SADS) scale. Demographic, laboratory, and prescription data were extracted from patient medical records and patients were asked to self-report over-the-counter pruritus medications.

Methods: Comparative differences in demographics and laboratory values at the time of determining the WI-NRS and SADS were analyzed using a Fisher's exact test with Bonferroni correction for categorical variables and the Mann-Whitney U test for continuous variables. Correlations between select variables and the WI-NRS score were assessed using linear regression analyses. Adjusted associations with moderate-to-severe CKD-aP were examined using odds ratios with corresponding 95% confidence intervals.

Results: A total of 307 patients completed the WI-NRS and 302 completed the SADS. Fifty-seven percent of patients reported some degree of CKD-aP, 31% of patients had moderate-to-severe CKD-aP, and 9% reported interference with quality of life (patients in SADS group C). Patients with moderate-to-severe CKD-aP and those significantly affected by CKD-aP (patients in SADS group C) were more likely to use over-the-counter treatments than patients with mild or no CKD-aP (P < .0001) and patients in SADS group A (P < .0001), respectively. Of patients with moderate-to-severe CKD-aP and whose CKD-aP significantly affected their quality of life (patients in SADS group C), 42% and 11.11%, respectively, did not use any form of treatments. Patients with moderate-to-severe CKD-aP had significantly higher parathyroid hormone (PTH; 0.02) and phosphate (P = .01). A higher body mass index (BMI) was associated with a greater WI-NRS score (R ² = 0.030, P = .003). Of patients with moderate-to-severe CKD-aP, 24% reported significant debilitation (patients in SADS group C). Finally, adjusted associations were found between moderate-to-severe CKD-aP and the following variables: BMI (OR = 1.05, 95% CI = 1.01-1.09, P = .02); serum phosphate (OR = 2.12, 95% CI = 1.15-4.00, P = .02); being a current smoker (OR = 0.46, 95% CI = 0.20-0.95, P = .04); and a serum phosphate greater than or equal to 1.8 mmol/L (OR = 2.33, 95% CI = 1.29-4.26, P = .01).

Limitations: There were some missing data points in patient records and patients' reports of over-the-counter medications. We could not assess whether patients actually had CKD-aP, or pruritus due to other causes. Treatment adherence could not be measured as well as whether treatments were specifically prescribed for CKD-aP. Moreover, our electronic medical record system could not capture prescribed topicals or pruritus-related medical conditions. Finally, this study did not assess physician's awareness of CKD-aP.

Conclusions: A substantial proportion of patients with moderate-to-severe CKD-aP reported a significant impact on quality of life. Elevated PTH, phosphate, and BMI were associated with CKD-aP. In addition, almost half of patients with moderate-to-severe CKD-aP did not use any treatments. There exist gaps and opportunities for care for patients with CKD-aP. Increased clinical attention to CKD-aP could identify those who may benefit from care interventions that improve quality of life.