The Reliability and Validity of the Turkish Version of the Fibrofatigue Scale

Objective: To validate translated Turkish version of the Fibrofatigue Scale [FFS]. Methods: The Turkish version of FFS was administered to a consecutive sample of 82 patients with fibromyalgia syndrome [FMS; 78 women]; mean age was 37 years and mean symptom duration was 2.3 years. The Turkish version of the Fibromyalgia Impact Questionnaire, the Beck Depression Inventory [BDI], and the Medical Outcome Survey Short Form-36 [SF-36] were documented. Reliability was tested by the test-to-test reliability [intraclass correlation coefficient] and internal consistency [Cronbach's alpha coefficients]. Construct validity was assessed by association with BDI and SF-36 [Spearman's correlation coefficient]. Paired t-test was used to determine the statistical significance of change score [responsiveness]. Results: The test-retest reliability and internal consistency of the FFS were excellent with intraclass correlation coefficient of 0.98 [0.97-0.99] and Cronbach's alpha of 0.74. The correlations between the FFS and the Fibromyalgia Impact Questionnaire items [rho=0.56], BDI [rho=0.52], and subscales of SF-36 [rho value ranging from -0.333 to -0.553] were adequate. The FFS score improved significantly after a four-week physical therapy program [P < 0.001]. Conclusions: The Turkish FFS is a reliable and valid instrument for detecting and measuring functional disability and symptom severity in Turkish patients with FMS.