Testing the iMTA Productivity Costs Questionnaire (iPCQ) for the use with chronic disease patients in Switzerland / Prüfung des iMTA Productivity Costs Questionnaire (iPCQ) für den Einsatz bei Patienten/-innen mit chronischen Krankheiten in der Schweiz

Abstract Background Complex interprofessional programs in health care are dependent on the valid measurement of outcomes. The iMTA Productivity Costs Questionnaire (iPCQ) is one of the few instruments measuring productivity in a comprehensive way which is available in German language. This study explores the validity of the German-language iPCQ with a focus on test content and response processes. The aim of this study is to validate the German version of the iPCQ for the use with people with chronic conditions in Switzerland and to make suggestions for adaptation to the developers. Method This study is a qualitative validation study. We conducted cognitive interviews with people with chronic illnesses and with other experts and analysed them based on the framework method. Results Participants had problems understanding many items and explanations and remembering correct answers. Furthermore, the study revealed construct-related problems in measuring the productivity of people with partial incapacity for work. Conclusions The results show that German version of the questionnaire needs improvement in order to guarantee validity and reliability.