Validity, reliability and factor structure of Hepatitis B Quality of Life Questionnaire version 1.0: findings in a large sample of 320 patients.

BACKGROUND Quality of life is of significant importance in chronic hepatitis B (CHBV). We aimed to assess the psychometric properties of the Hepatitis B Quality of Life Questionnaire v1.0 (HBQOL) in a large sample of 320 Iranian patients with CHBV. METHODS After adapting the Iranian version through forward-backward translation and expert panel discussion, we administered HBQOL together with Short-Form 36 (SF-36), Medical Outcome Study Social Support Questionnaire (MOS-SS), Hospital Anxiety and Depression Scale (HADS), and the Iowa Fatigue Scale (IFS) to 320 non-cirrhotic Iranian patients. We used principal component analysis with Varimax rotation to determine the factor structure. To evaluate the psychometric properties of HBQOL, test-retest and internal consistency reliabilities, divergent and convergent validity with other instruments, and discriminatory power were calculated. RESULTS Thirty-one questions loaded on to six factors (Anticipation anxiety, Stigma, Psychological well-being, Vitality, Transmissibility and Vulnerability) which explained 63.6% of total variance. Test-retest reliability was 0.66. Cronbach's α was 0.94 for the overall scale and between 0.7 and 0.9 for subscales, with the exception of the Vulnerability subscale. HBQOL and its subscales showed acceptable convergent and divergent validity with other instruments. Furthermore, Vulnerability subscale of HBQOL discriminated between patients with chronic active and chronic inactive hepatitis. CONCLUSION The Iranian version of HBQOL is reliable, valid, and sensitive to the clinical conditions of the patients. This instrument has acceptable factor structure to measure several aspects of quality of life in patients with chronic HBV.