PHASE-20: Ett nytt instrument för skattning av möjliga läkemedelsrelaterade symtom hos äldre personer i äldreboende

Background. Elderly persons may easily develop adverse drug effects. In Sweden, at least seven untested instruments are used for assessing possible drug-related symptoms in elderly people. Aim. The aim was to develop a more valid and reliable instrument for identification of possible therapeutic drug-related symptoms. Methods. The seven pre-existing instruments consisted of 39 symptoms, which were coordinated and then analyzed for content validity. After revision, the instrument included 19 symptoms or symptom-groups and one open variable. To assess the construct validity and reliability, the new instrument, PHASE-20, was tested in a randomized controlled trial with elderly persons living in two nursing homes before and after evaluation and correction of their therapeutic drugs. Results. PHASE-20 was found to possess an acceptable consistency, test-retest reliability, and internal validity. Construct validity was not supported in this study, as there were no significant differences between groups after the intervention. Therapeutic drug-related symptoms among elderly might be too heterogeneous to be captured into a screening instrument. However, PHASE-20 was welcomed by both patients and staff as a well structured, easily understandable, and useful assessment instrument. Conclusion. PHASE-20 can be used for identifying possible drug-related symptoms among elderly who are able to cooperate at least partly.