An international comparison of the reliability and responsiveness of the Duke Health Profile for measuring health-related quality of life of patientstreated with alprostadil for erectile dysfunction

OBJECTIVES. It is important that health measures are both reliable and resp onsive to clinical change. The aim of this study was to assess the reliabil ity and responsiveness of the physical, mental, and social health stales of the Duke Health Profile (DUKE). METHODS. Impotent males self-administered the Duke Health Profile before an d during treatment with alprostadil for erectile dysfunction during a 19-mo nth period. Subjects were 490 patients in the United States and 583 patient s in 12 other countries. Each of the three basic Duke Health Profile scales has only five items, and each is heterogeneous because each measures more than one health concept. RESULTS. Cronbach's alpha reliability estimates were: physical health, 0.68 for United States and 0.64 for other countries; mental health, 0.62 and 0. 52, respectively; and social health, 0.53 and 0.47, respectively. Alprostad il was expected to improve mental health primarily, and results of the stud y were consistent with this hypothesis. For example, at approximately 14 mo nths from therapy onset, mental health improved for patients both in the Un ited States (standardized response mean, SRM, = 0.17) and other countries ( mean SRM = 0.30), whereas physical health worsened in the United States and was unchanged in other countries, and social health was unchanged in the U nited States and improved in other countries. Maximum responsiveness was sh own for mental health in the other countries, where the mean standardized r esponse means at four follow-ups during a 19-month period were 0.11, 0.21, 0.30, and 0.36. CONCLUSIONS. This study provides support for the responsiveness of the Duke Health Profile mental health scale.