Development and Validation of a Disease-specific Outcomes Tool for the Assessment of Patient Benefits of Treatment for Hidradenitis Suppurativa: the PBI-HS

Hidradenitis suppurativa is a chronic skin disease associated with significant disease burden. To assess patients' treatment benefits, disease-specific outcomes measurement is needed. This study aimed to develop a questionnaire called Patient Benefit Index for hidradenitis suppurativa (PBI-HS). After an open-item survey, the items were condensed into a 26-item questionnaire on patient needs and benefits, with a 5-point Likert scale. In the validation study, construct and content validity, responsiveness, and feasibility of the questionnaire were assessed at 2 time points. A 26-item questionnaire was created following open-item generation by n = 72 patients. In the validation study, 3 items perceived as most relevant by patients were: "to be free of pain" (mean: 3.6 on a scale of 0-4), "to be free of inflammation" (mean: 3.6), "to have no more scars" (mean: 3.1). Significant correlations of PBI-HS at follow-up visit were found with the physical global assessment for hidradenitis suppurativa (HS-PGA) (r = -0.471; p = 0.000), number of inflammatory lesions (r = -0.359; p = 0.005), and DLQI (r = -0.383; p = 0.003), indicating less disease burden in patients with higher treatment benefits. The PBI-HS is a feasible and valid instrument to assess patient-reported treatment benefits in hidradenitis suppurativa.