Questionnaires for the subjective evaluation of patients with fibromyalgia: a systematic review

The objective of this study was to identify and review the subjective assessment tools validated in patients with fibromyalgia, identifying their most significant structural characteristics, as well as the psychometric characteristics analyzed in each of the identified instruments.

This systematic review was registered in PROSPERO with the following reference: CRD42022306878. It analyzed documents published until June 30, 2022, through the Medline, Pedro and Scopus, Dialnet, Cinahl and Latin Index databases. The keywords used were: 1) fibromyalgia; 2) assessment; 3) questionnaire; 4) reliability; 5) validity; 6) scale; and 7) validation study. Combined using the Boolean operators "AND" and "OR." The included articles were analyzed to extract: data on the structural characteristics of the questionnaires (including acronym, year of publication, number of items, sub-categories, time to complete the questionnaire, measurement range, cutoff score and cost) and psychometric characteristics of the selected questionnaires, including data on reliability (Cronbach's alpha and test-retest) and data on the validity of the questionnaires (content, construct and criterion validity).

Twenty-two studies containing 16 questionnaires were analyzed. The quality and risk of bias assessment was performed following the COSMIN checklist. In general, the quality of the subjective assessment studies validated in the population with fibromyalgia was good, with the exception of 5 studies, which did not exceed 5 points out of 10. The first questionnaire analyzed was published in 1991, and the last in 2020; the number of items ranged from 3 to 60. The most measured subcategories are function, overall impact and symptoms; other studies also include sleep and cognition disturbances. Only 6 studies described the time to complete them. The most analyzed psychometric characteristics were reliability (analyzed by 13 questionnaires), validity (analyzed by 7) and error measures (provided by only 3 of them).

There is a wide range of questionnaires specifically designed for patients with fibromyalgia that present good and/or excellent basic psychometric characteristics. The structural characteristics of the identified instruments were very heterogeneous, which makes it possible to select those that best adapt to the clinical/investigator scenario where the tool will be used.