Development and validation of a new instrument for the assessment of patient-defined benefit in the treatment of acne.
BACKGROUND
Benefit assessment of drugs and medical products has become a legally established feature of medical research. A standardized assessment of benefits using scientifically sound and valid methods is essential.


OBJECTIVE
Development, validation and practical evaluation of an instrument to record patient benefit in treatment of acne.


METHODS
In open interviews with n = 50 patients, possible benefits of the therapy from the patients' point of view were recorded. The item pool thus generated was reviewed by a panel of dermatologists, psychologists and patients and transferred to a 23-item questionnaire. This is used prior to therapy to assess patients' desired benefits and after therapy to record the perceived benefits. The therapy goals and the resulting benefits are then used to generate a weighted 'Patient Benefit Index' (PBI). The procedure has been tested for its validity and feasibility in n = 923 patients with acne.


RESULTS
Patients accepted the instrument and deemed it to be easily understandable. Additionally, the method proved itself to be internally consistent, constructively valid and sensitive to changes.


CONCLUSIONS
The Patient Benefit Index (PBI) is a valid and highly accepted practical instrument for recording patient benefit. The PBI permits an individualized, patient-weighted assessment of the benefits of acne therapy.
Augustin
Matthias
M
Department of Dermatology and Venereology, University Clinic Hamburg-Eppendorf, Germany. m.augustin@derma.de
Reich
Christine
C
Schaefer
Ines
I
Zschocke
Ina
I
Rustenbach
Stephan Jeff
SJ
D000152:Acne Vulgaris / Q000523:psychology / Q000628:therapy*; D005240:Feasibility Studies; D005858:Germany; D006040:Goals; D006801:Humans; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D017060:Patient Satisfaction; D011594:Psychometrics / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires