Fatigue is an important clinical finding in Hepatitis Virus Chronic Infection. However, the absence of scales to measure fatigue, translated and validated for Brazilian Portuguese, prevents access to information essential to clarify specific clinical conditions in this population.

To determine the psychometric properties of the Fatigue Impact Scale for Daily Use (D-FIS), in Brazilian Portuguese, in patients with hepatitis C virus (HCV) and hepatitis B virus (HBV) chronic infection.

In this cross-sectional study, the authors evaluated the D-FIS in 101 outpatients, followed at the reference hospital.

Relevant psychometric D-FIS results were: floor effect proved to be 1%; skewness was 0.46; item homogeneity was 0.59 and SEM (SD = 8.51) was 2.4. The Cronbach's alpha was 0.920 and item-total correlation yielded coefficients ranging from 0.65 (item 1) to 0.85 (item 3). In a linear regression model, fatigue and depression influenced the self-report quality of life.

This study concludes that the Fatigue Scale for Daily use in Brazilian Portuguese can be considered as a useful tool to verify the presence of fatigue in patients with hepatitis viruses B and C.