Abstract
No validated instrument exists to measure desire for improvement in psoriasis patients. To address this void, we conducted a single-center longitudinal study of 268 moderate-to-severe psoriasis patients to psychometrically validate the Desired Improvement Tool (DIT). The DIT is a single-item instrument scored 0–5 by the patient. A 0 indicates the patient is satisfied with disease level and does not desire further treatment. A 5 indicates a large amount of improvement is desired. The DIT demonstrated high test–retest reliability (Spearman, r = 0.97). Predictive and construct validity were moderate-to-high: r = 0.70 for BSA, 0.67 for PASI, and 0.56 for PGA and r = 0.67 for Life Quality Assessment (LQA), respectively. A sensitivity analysis revealed the DIT responded to changes in BSA. As a psychometrically valid tool, the DIT may guide clinical management of psoriasis patients by capturing an important clinical construct in an expedient and quantifiable manner.
Declaration of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.