Objectives: Fibromyalgia (FM) is a chronic syndrome characterised by widespread musculoskeletal pain associated with symptoms such as fatigue, sleep disturbances and cognitive impairment. Prevalence is higher in females but the application of the 2010/2011 and 2016 revision of the American College of Rheumatology (ACR) criteria reduced prevalence differences and the actual female:male ratio is approximately 3:1. Even if lately some studies have been conducted regarding FM gender differences, disease severity is still assessed using questionnaires, such as the Revised Fibromyalgia Impact Questionnaire (FIQR), designed and validated through a predominantly female sample. The aim of this pilot study was to compare the 21 items of the FIQR among male and female patients in order to evaluate the possible existence of a gender bias.
Methods: In this case-control study, consecutive patients with a diagnosis of FM (2016 ACR criteria) were asked to answer an online survey, including demographic characteristics, disease variables and the Italian version of the FIQR. Among the 544 patients that compiled the questionnaire, 78 patients, 39 males and 39 females, matched for age and disease duration, were consecutively enrolled in order to compare their FIQR scores.
Results: The univariate analysis showed that total FIQR scores and physical function domain scores were significantly higher in females and, among the 21 items of the FIQR, the female group obtained significantly higher scores in 6 of them. Our results showed that female patients obtain significantly higher scores in the FIQR total score and physical function domain score, in particular in 5 out of the 9 sub-items of the FIQR physical function domain.
Conclusions: These preliminary results indicate that the use of the FIQR as a severity index in male patients probably underestimates the disease impact in this group.