#1151 The prevalence and disease burden of CKD associated pruritus in Danish dialysis patients and current treatment practices—preliminary results
Authors: Peters Christian Daugaard , Larsen Gustav Østerlund , Kjærgaard Krista Dybtved , Christiansen Christian Fynbo , Hornstrup Bodil , Tietze Ida Nørager , Liem Ylian Serina , Bangstrup Marie , Rantanen Jesper Moesgaard , Uhde Milica 
Published: May 2024

Abstract

Background and Aims
Chronic kidney disease associated pruritus (CKD-aP) is rarely assessed by health care providers and potentially under-reported by patients despite the potential negative impact on health-related quality of life (HRQoL). Our aim was to investigate the prevalence of CKD-aP in a large cohort of Danish dialysis patients based on validated patient-reported outcome (PRO) instruments. A secondary aim was to investigate CKD-aP awareness among renal physicians including current treatment practices.

Method
The study was designed as a non-interventional, cross-sectional multicentre study. Chronic dialysis patients from four different regions in Denmark were invited to participate. CKD-aP was assessed with a one-page questionnaire containing Danish versions of two validated PRO instruments. The worst itch numeric rating scale (WI-NRS) was used for itch severity within the previous 24 hours (ranging from 0-10 with CKD-aP defined as WI-NRS score &gt;4 which equals moderate to severe CKD-aP). The 5-D itch scale was used as a multidimensional measure of itching and HRQoL. The five dimensions of the 5-D itch scale (degree, duration, direction, disability, and distribution) were summed together to obtain total score ranging from 5 (no pruritus) to 25 (most severe). CKD-aP awareness and treatment practices among doctors and nurses were investigated with a simple self-invented questionnaire.

Results
We recruited 500 chronic dialysis patients of which 87% were treated with in-center haemodialysis (HD), 10% with peritoneal dialysis (PD) and 3% with home HD (HHD). Mean age ± SD was 65 ± 14 years and 64% were males. Fig. 1 shows WI-NRS and total 5-D itch score distribution according to dialysis modality. CKD-aP prevalence (based on WI-NRS score &gt;4) was 19% (all patients regardless of dialysis modality) but tended to be higher among PD patients (29%) in comparison with HD (18%) and HHD (23%) as shown in Fig. 1. Odds ratio (OR) with logistic regression for CKD-aP based on WI-NRS score as a binary dependent variable (≤4 or &gt;4) and dialysis modality yielded: OR (PD vs. HD): 1.83 (0.96-3.49) and OR (HHD vs. HD): 1.35 (0.36-5.03). No pruritus (WI-NRS score = 0) was found in 61% of patients and 20% had mild pruritus (WI-NRS score ≤4). WI-NRS score correlated significantly with total 5-D itch score (Spearman's rank correlation coefficient (all patients): ρ = 0.80; P &lt; .001). Median total 5-D itch score (IQR) was 5 (5-10) based on all patients regardless of dialysis modality. Itch intensity over the past 2 weeks was rated moderate to unbearable by 23% and not present in 54% of patients. Itch duration was less than 6 hours in 91% of patients and 29% of patients had no change in itching over the past 2 weeks. Overall, the impact of CKD-aP on daily activities (leisure/social, housework/errands and work/school) was minimal in most patients but sleep disability (score &gt;1) was found in 18%. Sleep disability was significantly associated with higher WI-NRS score. Perceived CKD-aP prevalence (based on 28 questionnaires) was 20-40% according to most physicians (54%), 25% estimated it to be lower and 21% expected it to be higher. Topical therapy with fatty cream was the preferred treatment by most physicians followed by increased dialysis and non-sedating antihistamines.

Conclusion
Roughly one out of five patients on chronic dialysis treatment suffers from moderate to severe CKD-aP. HRQoL is negatively affected by CKD-aP primarily manifested as sleep disturbance. Most physicians tend to overestimate CKD-aP prevalence and prescribe fatty cream as their preferred treatment.