The prevalence of fibromyalgia in Brazil – a population-based study with secondary data of the study on chronic pain prevalence in Brazil

BACKGROUND AND OBJECTIVES: The prevalence of the fibromyalgia syndrome has been estimated in some Brazilian cities and regions, and previous population-based studies investigating this prevalence, as well as the profile of medical consultations are unknown. METHODS: This study used the database constructed by a previous study of authors to identify the prevalence of chronic pain in Brazil. The cases that reported pain for more than 6 months and with a diagnosis of fibromyalgia were selected. The studied descriptive variables were age, intensity and frequency of pain, pain interference in self-care, walking, working, social life, sexual life, sleep quality, if pain causes sadness or depression or influences the emotional aspects. The total sample was evaluated by rheumatologists and pain-expert doctors. RESULTS: Thirteen cases from the initial database were selected since they reported the diagnosis of the prevalence of the fibromyalgia syndrome representing 2% of the initial study population, average age 35.8 years (9.8). The predominance of the fibromyalgia syndrome was in females (n=11). Pain intensity was 7.3 (2.4), the frequency and duration of pain were constant in the majority of the sample (n=9). Most of the cases report a serious pain interference with sleep (n=8), many said that pain interferes with the work (n=5), irritability (5) and finally, some report that pain has a moderate interference in self-care (n=5), walking (n=6), social life (n=6), sexual life (n=5) and causes moderate sadness or depression (n=5). CONCLUSION: The prevalence of the fibromyalgia syndrome was estimated in 2% of the Brazilian population, based on secondary data of a study on chronic pain prevalence in Brazil. The data was collected in 2015-2016. The most reported complaints were intense and daily pain that interferes with sleep.