**1. Introduction**

The chronic illness Myalgic Encephalomyelitis or Chronic Fatigue Syndrome (we will use the acronym ME/CFS) is characterized by severe symptoms including profound exhaustion, muscle weakness and fatigability, pain, cognitive dysfunction, sleep disturbance, flu-like symptoms, and orthostatic intolerance [1–3]. The hallmark symptom of the illness is post-exertional malaise (PEM; i.e., the worsening of all symptoms after minimal exertion) [4,5]. To date, the etiology of ME/CFS is unknown, but the illness is associated with physiological abnormalities, e.g., an impaired energy metabolism [6,7], impaired cardiovascular function [8,9], as well as indicators of autoimmunity [10,11].

**Citation:** Froehlich, L.; Hattesohl, D.B.R.; Jason, L.A.; Scheibenbogen, C.; Behrends, U.; Thoma, M. Medical Care Situation of People with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in Germany. *Medicina* **2021**, *57*, 646. https://doi.org/10.3390/ medicina57070646

Academic Editors: Derek FH Pheby, Kenneth J. Friedman, Modra Murovska and PawelZalewski

Received: 5 May 2021 Accepted: 17 June 2021 Published: 23 June 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

In the United States, it is estimated that 1.09 million adults (0.42% of the population) and 0.40 million children (0.75%) are affected by ME/CFS [12], and a meta-analysis of 46 studies conducted in 13 countries showed a pooled prevalence of 0.39% for adults [13]. A base rate of 0.4% would translate to 332,000 individuals affected by ME/CFS (including 54,000 children and adolescents) in Germany. The condition is largely unrecognized by health professionals and the public. In the United States, it is estimated that 84% of adults and 95% of children and adolescents with ME/CFS have not been diagnosed [14,15] and that ME/CFS results in annual costs between USD 35.9 and 50.9 billion in medical bills and lost incomes [12]. In the UK, an average yearly productivity loss due to employment discontinuation was estimated as GBP 22,684 per patient [16]. For the EU, an annual burden of EUROS 40 billion was estimated, although specific estimations of the cost of ME/CFS in Germany and further European countries are lacking [17]. ME/CFS is also an important health issue in children and adolescents [15], and severely affected patients in this age group often have difficulties completing their education due to ME/CFS symptoms [18].

#### *1.1. Medical Care Situation of People with ME/CFS*

Studies conducted in the United States have investigated the medical care situation of people with ME/CFS and showed that they are medically underserved [19,20] in that they lack equal access to healthcare [21]. First, people with ME/CFS report barriers to accessing medical care. These access barriers include geographical factors (e.g., low number of specialists in the area, not being able to travel large distances to see a specialist) as well as financial factors (e.g., cost for appointment not covered by insurance, travel to specialist too expensive) [20,22]. Second, people with ME/CFS report low satisfaction with the medical care they receive. The number of specialists who are knowledgeable about ME/CFS and regularly treat patients with this condition is low [23,24]. For example, Sunnquist, Nicholson, Jason, and Friedman [20] surveyed 898 US American individuals with self-reported ME/CFS; 52% of participants had never seen a specialist and only 11.5% were regularly treated by a specialist. Furthermore, 71% of participants saw four or more physicians in order to receive a diagnosis. Whereas participants who saw a specialist reported being satisfied with medical care, the satisfaction with care from non-specialists (e.g., GPs, staff of emergency departments) was reported to be low [20,24,25]. Timbol and Baraniuk [25] investigated the satisfaction with medical care in the emergency department (ED) in a sample of 282 patients with physician-diagnosed ME/CFS. Fifty-nine percent of patients reported having visited an ED in the past, predominantly due to orthostatic intolerance. Patients were dissatisfied with ED care in that they indicated that the staff were not knowledgeable about ME/CFS and half of the staff attributed patients' complaints to stress, anxiety or psychological issues [25]. Other studies also showed that patients attributed their dissatisfaction with medical care to the inadequate training of physicians in treatment of patients with their illness [20,24].

Data on the access to and satisfaction with medical care of people with ME/CFS in Germany are currently lacking. If patients with ME/CFS in Germany faced similar barriers to medical care than in other countries and reported low satisfaction with medical care, this would indicate that they are also a medically underserved community. Based on research in the United States and the UK [16,20], patients with ME/CFS being medically underserved would be associated with individual and public financial losses also in Germany. Therefore, the first objective of the current research was to assess the medical care situation (i.e., access barriers and satisfaction with medical care) of people with ME/CFS in Germany.

#### *1.2. Assessment of ME/CFS Symptoms*

A second objective of the current research was to provide researchers and medical care personnel in German-speaking countries with a concise and time-efficient Germanlanguage questionnaire to assess and diagnose ME/CFS. Research points to multi-faceted causes of ME/CFS with 72% of patients reporting an infectious illness at the onset of the disease [26]. To date, there is no diagnostic biomarker or curative treatment [27–29]. However,

during the last decades the DePaul Symptom Questionnaire (DSQ) has been developed as a valid and reliable psychometric instrument to assess ME/CFS symptoms [30]. The questionnaire has been translated into multiple languages and is available in several versions, including a time-efficient short form encompassing only 14 items (DePaul Symptom Questionnaire Short Form; DSQ-SF) [30,31]. It was designed to measure the frequency and severity of symptoms from all domains of the ME/CFS Canadian Consensus Criteria: Fatigue, PEM, sleep, pain, neurocognitive, autonomic, neuroendocrine, and immune symptoms [32]. The DSQ-SF has been shown to identify a relatively similar number of patients than the longer, 99-item DSQ-1 version, and reliably distinguishes between patients with ME/CFS, adult controls, and patients with multiple sclerosis [31]. Furthermore, a brief questionnaire to assess PEM, the hallmark symptom of ME/CFS, was recently developed [33]. The DePaul Symptom Questionnaire Post-Exertional Malaise (DSQ-PEM) can be used as an efficient and reliable screening instrument to identify PEM in patients with ME/CFS. The instrument showed high sensitivity and specificity in differentiating between patients with ME/CFS and other fatiguing illnesses, namely multiple sclerosis and post-polio syndrome [33].

Thus, the second aim of the current research was to provide a translation of the DSQ-SF and the DSQ-PEM into German language. In the absence of biomarkers and established diagnostic tests, German versions of the questionnaires would provide a valuable tool for time-constrained research protocols to assess ME/CFS symptoms and for clinical practice to diagnose patients with ME/CFS in Germany and other German-speaking countries. This would be an important step towards improving patients' medical care situation.

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

#### *2.1. Participants and Procedure*

For the current project, we analyzed data collected for a superordinate research project [34], which was pre-registered at https://osf.io/spd9u/?view\_only=bc79e0d225 b9435caf6dd48fb6cd451b (accessed date: 22 June 2021). Participants with a self-reported diagnosis of ME/CFS were recruited via the four largest patient organizations for ME/CFS in Germany, their mailing lists, and social media. Data collection took place between May and June 2020. The online questionnaire took 30–45 min and was completed by 611 participants. We excluded participants who were under the age of 18 (*n* = 7) or did not consent to the inclusion of their data in the analyses (*n* = 3). Furthermore, we excluded participants who did not fulfil the Canadian Consensus Criteria for ME/CFS ([32]; *n* = 30; coded according to their responses to the DSQ-SF) [30]. Finally, as Cotler, Holtzman, Dudun, and Jason [33] showed that a duration of PEM longer than 14 h differentiated ME/CFS from other chronic diseases, we additionally excluded participants whose responses to the item "If you feel worse after activities, how long does this last" (item 9, DSQ-PEM) ranged between "1 h or less" and "11–13 h"; (*n* = 72). The final sample consisted of 499 participants.

After receiving information on data protection and the topic of the study, participants provided written consent in accordance with the EU General Data Protection Law, the research ethics guidelines of the American Psychological Association, as well as the Declaration of Helsinki. Then, they completed the DSQ-SF, DSQ-PEM, and SF-36, and provided information on demographics and illness history from the DSQ-2. Subsequently, they responded to items measuring their perceived barriers to medical care access and their satisfaction with medical care. For the superordinate research project, participants additionally completed measures of perceived causal attributions, perceived stigma, and satisfaction with social roles and activities (see pre-registration report, materials, and Froehlich, Hattesohl, Cotler, Jason, Scheibenbogen and Behrends [34] for a detailed description of these additional measures). Finally, participants were debriefed about the aims of the study and consented to the use of their data for analyses. The study received approval by the first author's institutional ethics commission. Scales for which no official translations were available were translated from English to German by the project team and back-translated by a professional translator. Materials, data, and analysis scripts are

available on the OSF [https://osf.io/5d8vu/ (use: 22 June 2021)]. The German translations of the DSQ-SF and the DSQ-PEM are displayed in Appendix A.
