Background Fibromyalgia (FM) requires an expert clinical examination that constitutes a potential limitation for the assessment of the diagnostic criteria of the American College Rheumatology (ACR) 1990 in some health settings. Fibromyalgia Rapid Screening Tool (FiRST) is a brief, simple and straightforward self-administered questionnaire with excellent discriminative value, of potential value for the detection of FM in patients with diffuse chronic pain.
Objectives The aim of this study was to investigate the reliability and validity of the Spanish version of the FiRST for detection of FM in primary health care centers
Methods The Spanish translation of the original FiRST French questionnaire was carried out by Rheumatologists and Professors of French and Spanish Language. Translation was performed in second person, to enable self or hetero application. This study was prospective and multicenter, including 404 consecutive patients diagnosed with FM according to the 1990 ACR modified criteria and 2010 ACR criteria. FM was diagnosed by specialists in Rheumatology. We also included a control group of similar age and sex, consisting of 147 Rheumatoid Arthritis (RA) patients and 219 Osteoarthritis (OA) patients. The modified 2010 ACR criteria were applied, the number of tender points was evaluated, and the FiRST questionnaire and Fibromyalgia Impact Questionnaire (FIQ) completed. Sensitivity, specificity and predictive value were analyzed for each of the 6 items of the FiRST questionnaire and for the global score (5 or 6 positive items), as well as the correlation between the global score and other parameters. Results obtained were expressed as median and interquartile (IC) range and analyzed with the Mann –Whitney U test using SPSS 15. P values less than 0.05 were considered significant.
Results The mean age of patients with FM was 51.67 years. The mean FIQ score was 73.29. The median disease duration was 12 years (IC range: 6-21). The median tender points was 16 (range IC: 14-18). 356 of 404 FM patients who met the 1990 ACR criteria and the 2010 modified criteria had a positive FiRST (scores 5 or 6). In the control group (AR + OA), 16 subjects had a positive FiRST and 343 a negative FiRST (scores or 4 or less). The sensitivity value (95% confidence interval) for global score (5-6 positive ítems) was 92 (88.9-95.1), specificity 87.4 (80.8-94), positive predictive value 95.7 (93.3-98.1), and negative predictive value 78.2 (70.6-85.9). There was a significant correlation between total FiRST (scores 5 or 6) and Widespread Pain Index (p<0.0001), Symptom Severity Scale (p<0.0001), time to disease progression (p<0.0001) and FIQ (p<0.0001).
Conclusions In patients with FM who met the 1990 ACR criteria and the 2010 modified ACR criteria, the overall sensitivity of the Spanish translation of the FiRST was slightly higher than in the original study. This questionnaire is easy to use and useful for the detection of FM patients in primary health care centers.
Disclosure of Interest : None declared