Introduction
Both in primary and in specialist care, caregivers frequently have to deal with or feel even confronted with patients consulting with medically unexplained (physical) symptoms (MUS). In the literature MUS prevalences vary between 30-50% [17, 35, 36]. MUS are categorized into syndromes without robust evidence for these classifications. They can be subdivided on the basis of symptom duration, number of symptoms and their impact on life quality and daytime functioning into mild, moderately-severe and severe.
Although the pathophysiology of MUS remains unclear, theoretical explanatory frameworks combine and integrate biological (physiological), psychological and social factors (e.g. in the biopsychosocial model, the stress-vulnerability model, stress model, the perceptual-cognitive model, the neurobiological model, vicious circles and emotions with references in sequence of the mentioned models [3, 10, 11, 12, 18, 28]. All models are only to a limited extent based on empiric research. Complementary to using an acceptable explanatory model, the quality of communication is crucial in the health care provider-patient relationship. In general and in particular in the setting of MUS, the quality of this relationship and of the mutual communication has a positive impact on health outcomes, patient satisfaction and therapeutic adherence [1, 13]. MUS patients often feel not-understood and many health care providers experience feelings of helplessness, potentially leading to frustrations and irritation on both sides and limiting the required patient-centeredness. This may trigger repeated consultations and increased consumption of resources, and provoke medical shopping.
Increased use of healthcare resources is even more frequent in patients with a different ethnic background [34]. Moreover the healthcare sector is challenged to deal with the current issues of migration and the presence of large groups of refugees in the European Union in a positive way. Not only patients with immigrant backgrounds, but also racial, ethnic, and sexual minorities experience disparities in access to healthcare, quality of care received, and caregiver services [7].
A positive approach often is lacking in the organization of care for MUS patients, of whatever cultural and ethnic background. This systematic review therefore aims at a critical synthesis of the current literature on the predefined domains of, first, syndromal definitions and epidemiology of MUS; second, organization of care for MUS patients, in order to define gaps as well as areas for improvement and derive recommendations.
Methods
A systematic search was carried out on the databases PubMed, Web of Science, Cinahl and The Cochrane Library using the keywords: ‘Medically unexplained (physical) symptoms (MUS)’, ‘Somatoform disorder’, ‘Functional syndrome’, ‘Diversity’, ‘Migrants’, ‘Ethnicity’, ‘Care models’, ‘Medical education’, ‘Communication skills’, ‘Health literacy’. The keywords were internally validated by the co-authors. A framework with two categories was predefined: syndromal definitions and epidemiology of MUS and organization of care. In order to qualify for this review articles needed to be 1) published between January 1, 2002 and September 30, 2019, 2) available as full text in English 3) categorizable as original research, reviews, meta-analyses or letters to the editor. Database screening was closed 2nd of October 2019. Only articles in the English language were included in order to avoid misinterpretations. Titles and abstracts were reviewed to verify inclusion criteria. If all inclusion criteria were present or if this remained unclear, the articles were fully read. All studies were screened for eligibility by two independent reviewers (PV, AM) who reviewed titles, abstracts and full text. Any disagreements were resolved by discussion and, if necessary a third reviewer (DV) was consulted. Additional literature was obtained through searching references in the manuscripts (snowball method).