Diagnosis and treatment of irritable bowel syndrome in primary care – do patient and provider characteristics matter?

• Applicant: Professor Dr. Olaf von dem Knesebeck
• Subject Area: Public Health, Healthcare Research, Social and Occupational Medicine
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 557410757

Background: Irritable bowel syndrome (IBS) is a common health problem in Germany causing a number of (chronic) symptoms that affect the quality of life of afflicted individuals. Primary care physicians (PCPs) are the first point of contact for most people with IBS. International studies suggest differences in the course and care of IBS according to social characteristics like gender, age, and migration history. Variations in medical decision making among PCPs may contribute to such differences but there is a lack of studies that systematically explore the role of patient and provider factors for diagnostic and treatment decisions in case of IBS. Objectives: The aim of this study is to explore the role of patient and provider factors for diagnostic and treatment decisions among PCPs in case of IBS. In this regard, gender, age, and migration history will be considered as patient characteristics, while gender of the PCP and the regional context of the practice (urban vs. rural) will be included as provider characteristics. Accordingly, the following specific research questions will be addressed: 1.) Do patient characteristics influence diagnostic and treatment decisions among PCPs in case of IBS? 2.) Do provider characteristics have an effect on the diagnostic and treatment decisions? 3.) Are there interactions between the patient and the provider characteristics regarding their diagnostic and treatment decisions? 4.) What are the underlying cognitive reasons that result in particular diagnosis and treatment decisions? Work programme: A factorial experimental design with portrayed video vignettes will be used. The vignettes will show medical encounters in which the patient presents with signs and symptoms that are typical for IBS. While the symptoms presented will be identical, patients will differ by gender (male vs. female), age (30 vs. 50 years), and Turkish migration history (yes vs. no). The video will be presented to PCPs in a videoconference. Afterwards, they will be interviewed concerning diagnosis and clinical management related to the patient presented using standardized and open-ended questions. The study population will consist of 128 randomly selected PCPs. As a sampling frame, a comprehensive database provided by the regional Associations of Statutory Health Insurance Physicians in the federal states of Bremen, Hamburg, Mecklenburg-Vorpommern, Niedersachsen and Schleswig-Holstein will be used. Selection will be made within four strata, defined by combinations of the physicians’ gender and region of the practice (urban vs. rural). The interview will include questions concerning possible diagnoses, level of certainty, examinations, test ordering, prescriptions, referrals, lifestyle recommendations, and what other information the physicians might seek. A subsequent qualitative interview segment will be used to explore how and why diagnostic and treatment decisions were made.

• DFG Programme: Research Grants