Benefit evaluation in the therapy of chronic wounds from the patients' perspective--development and validation of a new method.

Assessing therapeutic benefit of any drug and medical device is essential in registration and cost reimbursement decisions in Germany and in many nations. In this study, a method for the assessment of patient-relevant benefits in wound therapy was developed and validated. A total of 83 items on treatment benefit from the patients' perspective were collected in an open survey, including n = 50 patients with chronic wounds. The item pool was compiled to a list of 22 items by an interdisciplinary panel of experts including patients. The item list is presented prior to therapy to assess patient-relevant treatment needs and during or after therapy to establish if benefits have been attained. A weighed patient benefit index (PBI) is calculated from the items of both questionnaires. The instrument was examined for practical feasibility, reliability, and validity in a prospective study involving n = 172 patients with acute or chronic wounds treated by vacuum-assisted therapy. Validation criteria were: change in generic and disease-specific quality of life; judgment of efficacy by patients and physicians; treatment satisfaction; patients' willingness to recommend the therapy to others. Construct validity was given for all criteria applied. Cronbach's alpha was 0.88. The instrument was well-accepted by patients and rated relevant for the assessment of benefit in wound treatment.