Benefit evaluation in vitiligo treatment: development and validation of a patient-defined outcome questionnaire

Abstract

Background: In addition to clinical efficacy, patient-defined benefit assessment has become an important outcome parameter. Thus far, no such instrument has been developed for vitiligo.

Objectives: Development and validation of a patient-defined benefit questionnaire in the therapy of vitiligo.

Methods: Open questioning of 50 vitiligo patients generated 110 benefit items, which were converted into a 26-item questionnaire by a panel of dermatologists, psychologists and patients. This was used to record patient-defined needs prior to therapy and to evaluate patient benefit attained after therapy. A 'patient benefit index' (PBI) was formed on the basis of both. Validation was based on data of n = 1,023 vitiligo patients.

Results: The questionnaires were feasible in clinical practice, Cronbach's alpha (patient need questionnaire) was 0.94. The PBI showed convergent and discriminant validity with respect to quality of life and patient satisfaction.

Conclusion: The PBI for vitiligo is a valid instrument, which is highly accepted in practice for recording patient-reported benefit.