Validation of a German version of the Fibromyalgia Impact Questionnaire (FIQ-G)

Objective. To translate the Fibromyalgia Impact Questionnaire (FIQ) into Ge rman and to evaluate its reliability and validity for the use of German spe aking patients with fibromyalgia (FM). Methods. We administered the FIQ to 55 patients with FM (15 patients filled out the questionnaire 10 days later) together with German versions of the Stanford Health Assessment Questionnaire (HAQ), the Medical Outcomes Survey Short Form-36 (SF-36). and a tender Feint count (TPC). All patients were a sked about the severity of pain today (10 cm visual analog scale) and the d uration of symptoms, Tenderness thresholds were assessed by dolorimetry at all tender points with a Fisher dolorimeter and laboratory tests were obtai ned. Test-retest reliability was assessed using Spearman correlations. Inte rnal consistency was evaluated with Cronbach's alpha of reliability. Constr uct validity of the FIQ was evaluated by correlating the HAQ and subscales of the SF-36 as well its the TPC and the tenderness thresholds. Results. Mean age of participants was 54.3 years and mean duration of sympt oms 9.5 years. Test-retest reliability was between 0.62 and 1 for the physi cal functioning as well Is fur the total FIQ and other components. Internal consistency was 0.92 for the overall FIQ. Significant correlations were ob tained between the FIQ items, the HAQ, and the SF-36. Conclusion, The German FIQ is a reliable and valid instrument for measuring functional disability and health status in German patients with FM.