Table A1.

Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Checklist.

Section	Item	Prisma-ScR Checklist Item	Page
Title	1	Fibromyalgia Syndrome Pain in Men and Women: A Scoping Review	1
Abstract
Structured summary	2	Fibromyalgia syndrome (FMS) is a chronic musculoskeletal disorder of unknown etiology that affects up to 5.0% of the world population. It has a high female predominance, between 80 and 96%. Due to the low number of diagnosed men, research work has focused mainly on women. The extensive body of literature on sex differences in pain in the general population suggests that men and women differ in their responses to pain, with greater sensitivity to pain and a higher risk of clinical pain commonly observed among women. This review aims to (1) determine how pain is assessed or what types of questionnaires are used, (2) examine whether there are differences in pain characteristics between men and women with FMS and (3) describe how pain is conceptualized or manifested in patients at a qualitative level. In this study, the scoping review method of articles published in the last 5 years (2016–2022) was used. Ten articles were included. The most used questionnaires and scales to assess pain were the PVAS (Pain Visual Analogue Scale) and the FIQ (Fibromyalgia Impact Questionnaire). On the other hand, five categories were obtained: (1) qualities of pain, (2) uncertainty and chaos, (3) pain as an aggravating factor, (4) adaptation to the new reality and (5) communication of pain. It has been observed that both subjective perception and widespread pain are higher in women. Men, on the other hand, have a worse impact of the pathology, more painful experiences and more catastrophic thoughts about pain. In any case, the results have little statistical significance. To obtain higher quality results, it is essential to increase the sample of men with FMS in future studies in order to be able to deepen these differences.	1
INTRODUCTION
Rationale	3	The choice of the scoping review was mainly due to the heterogeneous nature of FMS in existing studies to date. The scoping review allows us to better group the literature according to its characteristics.	2
Objectives	4	The present review has focused the study of pain in men and women in FMS. Our objectives focused on (1) determining how pain is assessed or what types of questionnaires are used, (2) examining whether there are differences in pain characteristics between men and women with FMS and (3) describing how pain is conceptualized or manifested in the participants at a qualitative level.	3
Methods
Protocol and registration	5	Not applicable. The review protocol is in the process of being accepted by PROSPERO: www.crd.york.ac.uk/prospero/, accessed on 10 November 2022
Eligibility criteria	6	The identified studies were subjected to inclusion and exclusion criteria. To be included, studies had to be published from January 2016 to July 2022, available in full text, written in English or Spanish and use both quantitative (observational studies) and qualitative methodology.	3
Information sources	7	The bibliographic search was carried out during the months of February and July 2022. The electronic databases used for the search were PubMed, SCOPUS, CINAHL, Web of Science and Google Scholar. In each of these, an exhaustive search was performed using a combination of Boolean logic and truncations for the following keywords: “pain”, “fibromyalgia”, “men”, “women”, “conceptualization”, “manifestation”, “score” and “assessment”.	3
Search	8	The following search string was used for PubMed database, we used ((((“Fibromyalgia”(Mesh)) AND “Pain”(Mesh)) AND “Men”(Mesh)) OR “Women”(Mesh)) OR (“Pain Measurement/classification”(Mesh) OR “Pain Measurement/instrumentation”(Mesh) OR “Pain Measurement/nursing”(Mesh) OR “Pain Measurement/psychology”(Mesh)) OR (score) OR (concept*) OR (manifestation) OR (assessment).	3
Selection of sources of evidence	9	The electronic databases selected for the search were PubMed, SCOPUS, CINAHL, Web of Science and Google Scholar.	3
Data charting process	10	Data were extracted from full-text articles that met the objectives and inclusion criteria. Definitive data were obtained using a data extraction form with the following information: author(s), year of publication, country, study design, study objective(s), participants (sex and age range). In the case of quantitative studies, the types of questionnaires used were also considered. In the qualitative articles, for the review of the experiences of men and women with FMS, the authors proceeded to analyze the discourses related to the conceptualization or manifestation of pain by means of categories and subcategories.	4
Data items	11	The variables used for the data search were “pain”, “fibromyalgia”, “men”, “women”, “conceptualization”, “manifestation”, “score” and “assessment”.
Results
Selection of sources of evidence	12	Figure 1	4
Synthesis of results	13	Of the 10 studies that met the inclusion criteria, 7 were quantitative, 2 qualitative and 1 mixed. Sample sizes ranged from 5 to 4.342 participants. The female sex predominated with 56.7%. In all studies, the age range was 18 years or older; older subjects had a mean age of 56.6 ± 12.6 years. The pain assessment of the selected quantitative studies included a wide variety of questionnaires and scales. The most used were the PVAS (out of 10 or out of 100) and the FIQ. On the other hand, qualitative studies used tools such as focus groups, interviews, narrative and life history to describe how pain manifests itself in men and women with FMS. The PVAS and WPI were higher in female participants. In Wolfe’s study, males were older (64.9 ± 12.0 years) than females (59.7 ± 13.5 years). In contrast, in the Jiao study men were significantly younger p = 0.027 (43.6 years) than women (50.1 years). The FIQ and PCS were somewhat higher in men than in women in the Segura-Jiménez study, but without statistical significance. There were no differences for the rest of the scales. The review of the qualitative literature allowed us to identify the existence of categories related to pain. A total of five categories were obtained: (1) qualities of pain, (2) uncertainty and chaos, (3) pain as an aggravating factor, (4) adaptation to the new reality and (5) communication of pain. In the first category—pain qualities—we integrated the results related to the pain characteristics reported by patients in the chosen studies. The second category—uncertainty and chaos—describes how patients cope with chronic pain. The third category—pain as an aggravating factor—reflects the different causes of chronic pain in patients. In the fourth category—adaptation to the new reality—we show how patients make vital changes to continue living with pain. Finally, in the last category—pain communication—we show the importance of expressing emotions and sharing the experience of pain as a benefit for the person.	4–11
Discussion
Summary of evidence	14	This review provides an updated synthesis of fibromyalgia pain from different approaches to better understand it. The first objective of this review was to determine how pain is assessed, i.e., which questionnaires are commonly used. The results show that the PVAS (which assesses the subjective perception of global pain) and the FIQ (which assesses the impact of illness) were the most used tools. We contrasted whether there were differences in pain characteristics according to sex. We detected that the subjective perception of pain was higher in women, as was the generalized pain index (WPI). In contrast, FMS impact was higher in men as were painful experiences and PCS pain thoughts. Although several examples of epidemiological evidence have shown that chronic pain conditions are more prevalent among women than among men, in our review we only detected this in Jiao’s study, which revealed significant differences in pain according to sex. Women with FMS had worse values in the WPI questionnaire (generalized pain) and men with FMS had worse values in the SSS (severity of symptoms). Finally, through the use of qualitative methodology this review wanted to describe how pain is conceptualized or manifested in affected individuals. Pain, according to male participants in the studies by Sallinen and Mengshoel and Kueny, has qualities of being fluctuating. Also, agonizing and unbearable at the worst times. Unlike other studies, the pain of the men in Kueny et al. is of a localized type, not generalized and has a stabbing characteristic such as an arrow or sword. According to Ruschak’s study, the pain of men with FMS was also described as “like an arrow or heart attack” and of a fluctuating type; i.e., it was present in different parts of the body, not generalized. The chronicity and random nature of fibromyalgia pain causes much uncertainty and chaos in the lives of these patients. Fatigue and insomnia also entail major problems in their lives, which are closely linked to pain, which is their direct aggravating factor, a phenomenon also shared by the study of Ruschak et al. These in turn also limit them at all levels of their social relationships because the invisible nature of pain means that patients have to be their own advocates in front of others, because they do not believe them. These challenging situations full of negative attitudes have been previously described in other studies on FMS. According to Ruschak and colleagues, the lack of empathy shown by some healthcare professionals, as well as their family and friends, have had a very negative impact on patients’ health, especially mental health. Sallinen suggests that there is also a consequence on their identity, especially their masculinity, as it has to be renegotiated and reconstructed. All these changes in their lives are difficult to face, but necessary. Acceptance of the new reality helps people to move on, mainly with the help of others. This help begins with communicating their discomfort and finding a receptive listener so that they can talk about their pain.	12–13
Limitations	15	Some limitations must be mentioned. First, reducing the review to the last 5 years has led us to identify that there are fewer studies than we thought related to the subject. Secondly, in most of the mixed studies, the proportion of men to women is unbalanced; the low male representation is detrimental to them and limits their perspective. Finally, there are biases in some regions; we detected that there are countries in which FMS is not studied as much, for example Asian countries. This is probably due to the type of healthcare access they have or their cultural beliefs. In short, FMS remains an area that needs more awareness and investigation by researchers.	14
Conclusions	16	The results of this review provide updated information on FMS pain in both sexes. To date, we can see that pain remains a very complex, internal and private sensory experience and more so in men because FMS is still mostly conceptualized as a women’s disease. It has been observed in a few studies that both subjective perception and the generalized pain index are higher for women, but a worse impact, more painful and more severe experiences and also more catastrophic thoughts about pain in men should be considered. In any case, the results have little statistical significance and we consider that it is necessary to increase the sample of men in the studies so that these differences can be studied in greater depth. To improve pain care in these patients, we believe that there is a need for multidisciplinary management including educational interventions aimed at health care personnel on the different concepts of pain (subjective perception, impact of pain, widespread pain, localized pain, severity of symptoms, catastrophic thoughts about pain) to thus help to improve the understanding of individual and gender differences in pain. The results of this review have been made possible by the increasing inclusion of men with FMS and the awareness that the male experience and perspective is just as important as the female. Even so, we encourage further expansion of the male sample in future studies, because with the current results the significative differences in male and female pain did not reach statistical significance in all studies, probably due to the small sample of men.	13