Validity and reliability of a Persian version of the 12-Item Pruritus Severity Scale in hemodialysis patients with uremic pruritus

Background: The 12-Item Pruritus Severity Scale (12-PSS) is a multidimensional tool that evaluates pruritus intensity and duration along with an assessment of psychometric properties such as the patient´s mood, daily activities, and sleep pattern. Given its chronicity, uremic pruritus has a substantial impact on quality of life, so it is worth having a valid Persian questionnaire for assessing the various aspects of pruritus. This study was designed to evaluate the validity and reliability of the translated 12-PSS in hemodialysis patients with chronic uremic pruritus. Methods: Participants in this cross-sectional study were hemodialysis patients with uremic pruritus who were referred to the dialysis departments of three hospitals in Tehran, Iran. Following forward-backward translation of the 12-PSS to and from Persian, we assessed its content validity index (CVI) and reliability. Finally, we asked patients to respond to questions using both the Visual Analog Scale (VAS) and the 12-PSS. Results: Overall, 195 eligible patients participated in this study. The average age was 55.08 ± 12.34 years. The internal consistency (Cronbach’s alpha) of the 12-PSS was found to be 0.88, indicating strong consistency. The mean VAS and 12-PSS scores were 6.40 ± 2.63 and 11.52 ± 3.91, respectively, and the correlation between VAS and the total raw points of the pruritus intensity domain of the 12-PSS (questions 9 and 10) was strong (P-value < 0.05, r = 0. 90). Conclusions: This study showed that the translated form of the 12-PSS questionnaire has acceptable validity and reliability and has a strong correlation with the VAS in assessing pruritus intensity.