Measuring Patient-relevant Benefits in Pruritus Treatment: Development and Validation of a Specific Outcomes Tool

Background: The assessment of patient-relevant benefit is gaining importance in evaluating treatments. The 'Patient Benefit Index, standard version' questionnaire (PBI-S) is a validated instrument to assess patients' treatment needs and benefits in skin diseases. Before therapy, the patient rates the importance of predefined treatment goals; after therapy, he rates the extent to which these goals have been achieved. Thus far, no such instrument has been developed specifically for pruritus.

Objectives: Development and validation of a patient-relevant benefit questionnaire in the treatment of pruritus.

Methods: Fifty patients with pruritus were questioned on impairments due to pruritus and treatment needs. Four treatment objectives not already covered by the PBI-S were added to obtain a disease-specific instrument. This was tested for feasibility by 36 patients with pruritus and validated in a sample of 100 patients with pruritus.

Results: The instrument was feasible in clinical practice. There were < 2% missing values. Cronbach's alpha of the needs questionnaire was 0.93. Convergent validity was demonstrated with respect to reduction of pruritus and quality of life.

Conclusions: The PBI for pruritus is a feasible, reliable and valid instrument that is highly accepted in daily routine for recording patient-reported benefit.