The following is a summary of “Development and Validation of a Patient-Reported Outcome Measure to Assess Disease Control in Chronic Prurigo,” published in the January 2024 issue of Dermatology by Metz, et al.
Chronic prurigo (CPG), including prurigo nodularis, poses significant challenges in treatment and profoundly impacts patients’ quality of life. For a study, researchers sought to develop and validate the Prurigo Control Test (PCT), a tool designed to assess disease control in CPG, and to establish a cutoff value indicative of controlled disease to guide treatment decisions.
The qualitative study adhered to current guidelines for developing patient-reported outcome measures, involving the generation and validation of the PCT. The process included item generation, reduction, and selection, followed by testing for reliability and validity. The study was conducted across two expert centers in Germany, spanning from February 2017 to November 2019. The final PCT comprised 5 items with a recall period of 2 weeks. A cutoff value of 10 points or higher was established to distinguish between well-controlled and poorly-controlled CPG.
Among the 95 patients included in the validation study, with a median age of 63 years, the PCT demonstrated good internal consistency reliability (Cronbach α, 0.86) and high convergent validity. It also exhibited good known-group validity, effectively discriminating between patients with varying degrees of prurigo control. Test-retest reliability was high, with an intraclass correlation coefficient of 0.94, indicating excellent reproducibility.
The Prurigo Control Test (PCT) developed in the qualitative study proved effective in assessing disease control in patients with CPG. Its retrospective nature, brevity, and simple scoring system make the PCT suitable for both clinical practice and research trials, offering a valuable tool for evaluating treatment outcomes in CPG patients.
Reference: jamanetwork.com/journals/jamadermatology/article-abstract/2814079