Quality-of-life evaluation in hidradenitis suppurativa in Australia: Validation and outcomes of the HiSQOL questionnaire

Background: Hidradenitis suppurativa (HS) is a debilitating chronic inflammatory disease with significant impact upon quality of life. Generic quality-of-life measures suffer from decreased face validity and content validity, leading to the development of disease-specific quality-of-life measures such as the Hidradenitis Suppurativa Quality of Life (HiSQOL) outcome measure. The aim of this study was to validate the use of the HiSQOL in the Australian population and evaluate the quality-of-life impact in HS patients in Australia.

Methods: A total of 301 patients were recruited and consented to be involved in this study. All participants were invited to complete the HiSQOL questionnaire along with basic demographic and disease information, the DLQI and HADS anxiety and depression scale. Participants were then asked to repeat the questionnaires 14 days later to assess test-retest reliability.

Results: The mean HiSQOL score was 46.5 out of a possible total score of 76 (SD = 24.2) indicating a very large impact on quality of life. Based upon the published validity bands this corresponds to a very large impact on quality of life. Validation statistics indicated a high degree of internal consistency (Cronbach's alpha = 0.956) with expected levels of convergent validity and excellent test-retest reliability (p = 0.95). Multiple regression analysis indicated individuals with a younger age of onset and positive family history had significantly greater quality-of-life impact as measured by the HiSQOL.

Conclusions: The HiSQOL is a valid, reliable measure for assessing the quality-of-life impact of HS. Significant factors influencing quality of life include age of onset and family history. Longitudinal measurements will enable evaluation of the impact of therapy upon QOL in the Australian context.