Usefulness of the Japanese version of the 5-D itch scale for rating pruritus experienced by patients undergoing hemodialysis

Abstract

Background: Pruritus in patients undergoing hemodialysis reduces quality of life via insomnia and depression, and negatively affects prognosis. For diagnosing pruritus, selecting therapeutic strategies, and determining therapeutic outcomes, methods are needed for objectively quantifying the degree of itchiness. In 2015, the Japanese version of the 5-D itch scale (5D-J), originally developed in the USA in 2010, was developed as a simple self-Administered questionnaire; it evaluated the degree of itchiness based on five components: (1) duration of itchiness, (2) degree of itchiness, (3) direction of itchiness, (4) disability caused by itchiness, and (5) distribution of itchiness. 5D-J is useful for comprehensively assessing multiple elements related to itchiness. We used 5D-J to assess the degree of itchiness experienced by patients undergoing hemodialysis to investigate its clinical usefulness. Methods: Subjects were 336 patients undergoing maintenance hemodialysis at our facility in October 2016; they were selected from 383 patients, of whom 20 were excluded because their itchiness had a dermatologic origin and 27 were excluded because their localized itchiness was related to vascular access, respectively. The status of itchiness (duration, degree, direction, disability, and distribution) of the patients was surveyed in October 2016 using 5D-J; total scores were calculated and used for assessing the itchiness experienced by patients. We additionally investigated whether 5D-J scores correlated with visual analog scale (VAS) and Shiratori severity scores for pruritus. Results: Degree was reported as "not present" by 124 patients (36.9%), "mild" by 164 (48.8%), "moderate" by 46 (13.7%), "severe" by 2 (0.6%), and "unbearable" by 0 (0%). Total score was 5 points in 55 patients (16.4%), 6-9 in 176 (52.4%), 10-14 in 95 (28.3%), 15-19 in 9 (2.7%), 20-24 in 1 (0.3%), and 25 in 0 (0%). The 5D-J total and VAS scores were strongly correlated (r = 0.7159; p < 0.001). The 5D-J total score correlated with "daytime itchiness" (r = 0.6441; p < 0.001) and "nighttime itchiness" (r = 0.6352; p < 0.001) on the Shiratori severity score. Conclusions: 5D-J may be useful for objectively assessing itchiness experienced by patients undergoing hemodialysis.