**1. Introduction**

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a poorly understood, serious, complex, multi-system disorder, characterized by symptoms lasting at least six months, with severe incapacitating fatigue not alleviated by rest, and other symptoms, many autonomic or cognitive in nature, including cognitive dysfunction, sleep disturbances, muscle pain, and post-exertional malaise, which lead to marked reductions in functional activity and quality of life [1–3]. Symptomatology, severity and disease progression are all very variable. ME/CFS is most common between the ages of 20 to 50 years, but it can affect all age groups. Around three quarters of patients are female [4–6]. There are no Europe-wide prevalence data, but there is a commonly held belief that there are some 250,000 sufferers in the U.K. [7]. If this is correct, there may be some two million patients in Europe as a whole.

The European ME/CFS Research Network (EUROMENE) was established to promote collaborative research on the condition across Europe. It is currently in receipt of EU funding from the Collaboration on Science and Technology Association (COST, https://www.cost.eu) to support network activities. It seeks to review the current state of the art and to identify gaps in knowledge of ME/CFS. EUROMENE also aims to shed light on the overall burden of disease, and also to investigate possible biomarkers, diagnosis and treatment [8].

Previous work by the socioeconomic working group of EUROMENE identified widespread failure by GPs to diagnose ME/CFS as an important factor contributing to underestimation of the incidence and prevalence of the illness, and hence of its economic impact [9]. The group conducted a pilot survey among EUROMENE participants to assess the position regarding GP diagnoses of ME/CFS [10]. The survey findings suggested that under-diagnosis in primary care was a Europe-wide problem, and that estimates of the public health burden of the illness, even where these exist, are therefore likely to underestimate substantially its true prevalence.

A systematic review of qualitative studies published in 2013 and concerned with barriers to the diagnosis and managemen<sup>t</sup> of CFS/ME in primary care identified 21 studies. This review demonstrated a limited understanding of ME/CFS by GPs [11]. We conducted a comprehensive literature review with the aim of assessing whether primary care doctors' awareness, understanding and acceptance of ME/CFS as a disease has changed in the intervening years.

#### **2. Materials and Methods**

A MEDLINE search was carried out, covering the period from 1946 until 20 August 2020. The inclusion criteria were focuses on general practice, family practice, primary care or primary health care, and myalgic encephalomyelitis or chronic fatigue syndrome (including ME/CFS, CFS/ME, and post-viral fatigue syndrome). Exclusions were papers not addressing GP attitudes, knowledge or understanding of ME/CFS or any of its synonyms.

The papers were sorted into categories following the synthesis without meta-analysis (SWiM) methodology. Categories were defined on the basis of the focus of the enquiry (patients, GPs, database and medical record studies, evaluation of a training programme, and overview papers), and whether the studies were quantitative or qualitative in nature. These are summarised in Table 1 below. One of the papers was the review referred to above [11].


