Desired Improvement Tool (DIT): A tool to assess desire for improvement in psoriasis patients

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.