A new test for chronic prurigo could be a first patient-reported outcome measure for the condition.

Researchers have introduced a 5-item Prurigo Control Test (PCT), in what could be the first patient-reported outcome measure for determining disease control for chronic prurigo (CPG). 

This tool, according to the researchers, was designed to assess disease control in CPG and provide dermatologists with a reliable metric for gauging treatment efficacy. The qualitative study, consisting of 95 patients and conducted following established guidelines for patient-reported outcome measure development, evaluated the PCT through phases of item generation, reduction, and selection. The final set was pared down following impact analysis, interitem correlation and a review for content validity, and consisted of 5 items with a 2-week recall period. 

Results from the validation study suggested efficacy. The tool accurately identified patients with well-controlled vs. poorly controlled CPG at a cutoff value of 10 points or higher. The authors reported a high degree of internal consistency reliability (Cronbach α, 0.86) and a high degree of convergent validity. Additionally, the PCT demonstrated its ability to discriminate between patients varying in prurigo control, suggesting good known-group validity.

"This qualitative study showed that the PCT is able to assess disease control in patients with CPG," the authors wrote. "Its retrospective approach, brevity, and simple scoring likely make the PCT suitable for clinical practice and trials."

Source: Metz M, Zeidler C, Hawro T, et al. Development and Validation of a Patient-Reported Outcome Measure to Assess Disease Control in Chronic Prurigo. JAMA Dermatology. Published online January 17, 2024. doi:https://doi.org/10.1001/jamadermatol.2023.5519