Chronic Fatigue in the Internal Medicine Outpatient Clinic: a Mixed-methods Quantitative and Qualitative Study

With this study, the investigators aim to answer the following research questions: 1. In what percentage of cases does the diagnostic process conducted during a fatigue consultation at the internal medicine outpatient clinic contribute to a somatic diagnosis? 2. What are the experiences of patients presenting with fatigue at the internal medicine outpatient clinic when a consultation, including diagnostic testing, does not lead to a diagnosis? To address question (1), the investigators will conduct a retrospective data analysis using information from HiX, an electronic health record (EHR) system. To answer question (2), the investigators will conduct a prospective qualitative study through interviews.