FM is the rheumatic disease which most effects the quality of life of patients since they report a significant impact on their physical and intellectual capacity, personal relationships, etc. [22] In the majority of cases patients are unable to work and perceive their health to be poor. A diagnosis may not be made until many years after the initial onset of symptoms FM is a chronic disease which affects the functional capacity of patients to such an extent that they may be unable to carry out some of their usual daily activities [23]. It is a prevalent disease and our work corroborates many of the points that have been shown in other epidemiological studies, such the wider prevalence in women and the growing trend of cases diagnosed at all ages.
Following a literature review, we were unable to find similar studies which have been carried out in Catalonia with the same sample size in order to carry out a comparison. However, in general the results are in consonance with studies conducted in other countries. The EPISER study on rheumatic diseases [24] establishes a prevalence of FM in Spain of 2.4%, with a higher prevalence in females than males and an upward trend over time. These results largely coincide with those in our study: in 2010 the prevalence was 0.75% in women and 0.03% in men, while in 2017 it stood at 2% in women and 0.10% in men. In line with this, in our cohort studied we found that the diagnosis of FM was less common in male than female. In addition, several studies pointed out to a different pain sensibility threshold and associated factors to subjective perception to pain in both sex. Female generally exhibit higher sensitivity to noxious stimuli not only from mechanical pressure, but also from electric, thermal, ischemic, and cold stimuli [25]. It is plausible that complex biological factors from hormonal influences and psychosociocultural factors including sex expectations may influence too. Sociocultural beliefs about femininity and masculinity also appear to be an important determinant of pain responses among sexes as pain expression is generally more socially acceptable among women, an effect which may lead to biased reporting of pain. In a study [26], both men and women believed that men are less willing to report pain than woman. Such gender role expectations may contribute to sex differences when experimenting pain [27]. Therefore, we cannot exclude that the existence of other cultural, socioeconomic factors or differences between both sexes in terms of the perception of the disease, behavior and attitudes towards health services, may explain this lower prevalence of the disease in men [28]. Another study confirms that males with FM tend to endure pain for longer periods of time than females before seeking treatment. Unfortunately, there is still a paucity of evidence on clinical characterization and treatment options when FM occurs in males. With respect to age, the highest prevalence in our study was found in the 55–65 and 55–65 age groups, with the latter having the highest prevalence. These results concur with the EPISER study in which the group with the highest prevalence was aged 40–59 years. In the EPIFFAC study [29] the mean age of its sample of 325 people was 52 and a study carried out in the United States found the highest prevalence in the group aged 50–59 years.
In Catalonia, a study was carried out between 2011–2013 on patients with fibromyalgia in Primary Care Centres which calculated the mean age of the sample to be 55 years. 97.8% of patients treated were women while 2.2% were men [30]. These results coincide with the results obtained in this study, as the most prevalent age is found between 55 and 64 years in both women and men.It is worth highlighting the prevalence of FM in rural areas.
Although the published literature has not indicated whether a rural environment can be beneficial or protective with regard to FM compared to an urban one, in our results there is a slightly higher percentage of FM in rural areas and a slight positive correlation with the deprivation index in urban areas [19]. It is also observed that the prevalence of FM has been slightly higher in individuals in areas with greater deprivation than individuals in areas with less deprivation.
The consumption of substances such as alcohol and tobacco, could be associated with an FM diagnosis, since some studies show an intake of alcohol and tobacco (41.4% and 38.5%, respectively) above the average of the general population (19% and 36%) [31]. However, in our sample only 14.2% of patients diagnosed with FM have low-risk alcohol consumption and 0.49% have a high risk, 49.8% are non-smokers and 24% are smokers.”
FM is not a disease associated with high mortality rates, but it does have significant repercussions on direct and indirect healthcare costs [32]. Over the 7 year study period, 92% of the individuals diagnosed were still alive, 1.63% had died and the remainder had left the Catalan health system (6.39%).
The results of our study may contribute to clinical practice and the review and planning of new protocols in primary care to more effectively address people diagnosed with FM., in addition
4.1. Study limitations
Some of FM’s symptoms can be confused with those of other rheumatic diseases and this, in turn, can lead to incorrect coding of the diagnosis of FM, We propose to increase diagnostic adequacy by referring patients to specialized FM units to confirm the diagnosis. This study cannot be extrapolated to other countries since it has been conducted in a region of Spain.