Background

Fibromyalgia is a chronic disease characterized by persistent diffuse pain, fatigue, sleep disorders and, in most cases, other associated functional symptoms [1]. This disease has a common framework, with an estimated global prevalence of between 5 and 15% of the general population [2,3,4]. In recent years, several mechanisms have been studied, but their etiopathogenesis remains unknown [1, 5].

Patients with fibromyalgia often report worsening of quality of life, changes in social life and reduced productivity at work, especially when there are associated depressive symptoms. These facts can generate negative effects on personal and social life, along with significant public health expenditures caused by treatment and work withdrawals [6,7,8,9,10,11].

Although the complaints of productivity reduction in patients with fibromyalgia are frequent, there are few studies in the literature that can measure this probable consequence of the disease.

The objective of this article is to evaluate the number of work withdrawals in patients with fibromyalgia and other soft tissue disorders (ICD M79 and variants) by analyzing the disability benefits granted by Social Security in Brazil over a period of 10 years.

Methods

A retrospective study was conducted in which the disability benefits (DBs) granted by Social Security in Brazil were analyzed as a function of fibromyalgia and other soft tissue disorders classified as ICD M79 and its ICD-10 variants, which are specified in Table 1.

Table 1 List of ICD-10 disease codes from group M79 and its variants
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The assessment consisted of two types of benefits: disease assistance (temporary work withdrawal) and disability retirement (permanent work withdrawal) during the period from 2006 to 2015.

The data for this study were obtained through the E-SIC portal and the official Social Security platform in which spreadsheets and graphs were composed of numerical and descriptive variables [12, 13]. A qualitative and quantitative analysis of the data was performed.

Results

A total of 24,815,916 disability benefits were provided by Brazilian Social Security in the period from 2006 to 2015. Among these benefits (provided for all diseases), 95,882 of the benefits (0.39%) were attributed to ICD M79 and variants.

When the DBs were analyzed according to the ICD M79 group, 69,420 benefits (72.3%) were granted to women and 26,562 (27.7%) to men. The age and salary distributions were also calculated and can be seen in Tables 2 and 3. In relation to the types of benefits, we found 93,556 (97.5%) benefits from temporary work withdrawal (disease benefit) and 2426 (2.5%) permanent retirements (disability retirement).

Table 2 Number of disability benefits granted by ICD M79 (and variants) distributed by age group
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Table 3 Distribution of disability benefits for M79 (and variants) by salary range in minimum wages (MW) from 2006 to 2015
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The distribution of concessions per year was analyzed, and more benefits were found in the years 2006 to 2008. The number of benefits per year and the total benefits in the period from 2006 to 2015 can be seen in Table 4.

Table 4 Disability benefits granted by social security for ICD M 79 and variants in the period from 2006 to 2015
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Discussion

Fibromyalgia has the potential to cause functional impairment in patients when compared with the normal population, especially when there is exacerbation of painful symptoms or associated psychiatric conditions [14,15,16,17]. Limitations in work capacity caused by pain, fatigue, cognitive alterations, reduction of muscular strength and physical resistance have been described in the literature [18,19,20].

The evaluation of the number of work withdrawals for a given disease is important for measuring the disease’s impact. In this article, we evaluated the number of work withdrawals by analyzing benefits granted by Social Security in Brazil between 2006 and 2015. We did not find similar articles in the literature for comparison.

In our study, we noted the granting of 95,982 benefits for this group of diseases (ICD M79 and variants) in the analyzed period. The occurrence of 72.3% of the benefits for the female sex can be easily explained by the very incidence of fibromyalgia and other diseases in this group.

In relation to the age group, the age with the greatest number of benefits was 40 to 49 years (30.3% of the total), with the greatest number of work withdrawals being between 30 and 59 years old: 88,867 (92.6%). It is important to emphasize that these withdrawals are predominant during the time of full professional capacity. Within this context, some authors have warned about the need for early evaluation and diagnosis and better management of fibromyalgia to minimize the personal consequences and expenses of withdrawals. The maintenance of the functional and working capacity of the individual, besides the improvement in the quality of life, has also been advocated [20].

Regarding the annual distribution of benefits, there were greater numbers in the years 2006, 2007 and 2008. The rest of the period remained similar. When comparing the initial and final years of the analyzed period, we observed a significant reduction in the number of concessions: 15,562 in 2006 to 6163 in 2015. It is believed that during the analyzed years, there was progressively greater knowledge on the part of the physician regarding fibromyalgia and the current recommendation that removal from work in general should be avoided [20]. Increased rigor when granting benefits by Social Security may be another explanation for the decrease in the number of benefits granted.

The amount paid for disability benefits was mostly up to two minimum wages (89%), which likely represents the income of most of those insured by the National Institute of Social Security / Social Security. No data were provided on the duration of each benefit.

Although the vast majority of the benefits granted (97.5%) were due to temporary withdrawals from work (disease assistance), the large number of such benefits represents an important measure of the financial impact of the disease. In addition, we observed 2426 cases of disability retirement, a fact that deserves extreme attention due to the great personal and social repercussions resulting from the early and permanent departure from the labor market.

Conclusions

In the present study, we analyzed the group of diseases defined in ICD-10 as M79 and its variants, which encompasses several soft tissue disorders. Future research with specific evaluation for fibromyalgia in patients diagnosed by a rheumatologist should be encouraged.

This paper presents some limitations, such as its retrospective character and the lack of data regarding the occupation of individuals and the duration of benefits. However, it is the first article that analyzes the social security benefits granted by ICD M79 in Brazil through an official and reliable database. The analysis covered an extended period, which provides us with relevant information on departures from the last decade. These data may serve as a basis for further studies and should alert professionals and specialist societies to the need for adequate management of fibromyalgia to reduce work withdrawal and its consequences.