To investigate the reliability and validity of the Spanish version of the Fibromyalgia Rapid Screening Tool (FiRST), a brief questionnaire for the detection of fibromyalgia (FM) in patients with diffuse chronic pain seen at primary care health centres.
The original FiRST French questionnaire was adapted to a Spanish version following the guidelines of the Rheumatology Spanish Society Study Group of FM, and the help provided by professors of French and Spanish Language. In a prospective and multicentre study, patients with chronic pain were initially divided into two groups: a group that included patients that had been diagnosed with FM according to the 1990 ACR criteria and the 2010 ACR preliminary criteria (n=404), and a non-FM (control) group composed of rheumatoid arthritis (RA) (n=147) and osteoarthritis (OA) (n=219) patients. Patients from the FM group were evaluated by assessing tender point assessment, Widespread Pain Index (WPI), Symptom Severity Scale (SSS), FiRST questionnaire and Fibromyalgia Impact Questionnaire (FIQ). The non-FM group was evaluated by means of FiRST, WPI and SSS. Sensitivity, specificity and predictive value as well as the correlation between the global score and other parameters were assessed.
356 of 404 FM (88.1%) patients who met the 1990 ACR criteria and the ACR 2010 preliminary criteria had a positive FiRST. In the control group (AR plus OA), only 16 (4.4%) subjects had a positive FiRST. The sensitivity value was 92% (95% confidence interval CI: 88.9-95.1), specificity 87.4% (95% CI: 80.8-94.0), positive predictive value 95.7% (95% CI: 93.3-98.1), and negative predictive value 78.2% (95% CI: 70.6-85.9). A significant correlation between the total FiRST score (patients with score 5 or 6) and WPI (p<0.0001), SSS (p<0.0001), time to disease progression (p<0.0001) and FIQ (p<0.0001) was found.
FiRST questionnaire is a useful tool for the detection of FM in primary care health centres.