Validation of a German Version of the Fatigue Impact Scale FIS-D

Abstract

OBJECTIVE: The Fatigue Impact Scale, FIS, is an internationally used instrument for the assessment of the impact of fatigue on Health-Related Quality of Life, HRQOL, also in patients with chronic liver diseases. In the German-speaking countries a validated instrument for measuring the impact of fatigue on patients with chronic liver diseases has not been available so far. METHODS: The German linguistic adaptation of the FIS using a forward-backward procedure was administered to 204 patients (age 52,7 +/- 13,9 years; 47 % female, 53 % male, 45 % no cirrhosis, 22 % Child's A, 15 % Child's B and 17 % Child's C cirrhosis; 53 % with chronic viral hepatitis, 32 % with alcoholic and 15 % with other liver diseases) of a secondary care hospital. The following internationally accepted instruments were used for validation: The Short Form Health Survey, SF 36, the Hospital Anxiety and Depression Scale German Version, HADS-D, and the Giessener Symptom Scale, GBB 24. Fifty patients in clinically stable situation filled out the FIS-D within 3 - 8 days. RESULTS: The acceptance of the FIS-D was high with 98 % answered items. The internal consistency of the three subscales was excellent (0.94 - 0.96), the test-retest reliability of the three subscales was good (0.72 - 0.83). The correlation coefficients with the validation instruments ranged between 0.49 and 0.80 (all p < 0 001). No differences in the FIS-D subscale scores were found in patients with and without cirrhosis and between the different Child-Pugh stages of liver cirrhosis. Patients treated with tranquilizer or antidepressants scored higher in the FIS-D than patients without this treatment (p < 0.05). CONCLUSION: The FIS-D is well accepted by patients in clinical routine care and has been shown to have good acceptance and reliability in the assessment of fatigue in chronic liver patients.