HiSQOL-mini: Development and Validation of a Shortened Version of the Hidradenitis Suppurativa Quality of Life (HiSQOL) Instrument

Background Hidradenitis suppurativa (HS)-specific quality of life (QOL) is one of six core domains for HS studies defined by HIdradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC). The 17-item Hidradenitis Suppurativa Quality of Life (HiSQOL©) questionnaire was developed and validated by HISTORIC to measure this domain. A shortened version would be easier for routine clinical use. Objectives To produce a shortened version of HiSQOL by selecting a subset of the original 17 items. Methods Item selection for HiSQOL-mini was informed by correlation analyses on two datasets from the Treatment of Hidradenitis Suppurativa Evaluation Study (THESEUS) and the BE HEARD I and II Phase 3 trials. Spearman’s rank correlation coefficients were calculated between each item and the HiSQOL total score after omitting that item. Two consensus workshops were then conducted, with patient research partners (PRPs) leading the discussions, to finalise the items for inclusion. Analyses to assess psychometric performance and derive interpretation thresholds for HiSQOL-mini were conducted using the BE HEARD dataset. Results In the symptoms sub-domain, pain exhibited the highest correlation with HiSQOL total score and was unanimously selected at the end of Workshop 1. In the psychosocial sub-domain, the ‘down or depressed’ item performed best from THESEUS data, while the ‘concentration’ and ‘embarrassed’ items performed best from BE HEARD data. Related to content validity, PRPs prioritised ‘down or depressed’ in the discussions. ‘Walking’ performed well in both datasets and PRPs further recommended inclusion of a second activities-adaptations item, ‘getting dressed’. HiSQOL-mini demonstrated good validity, reliability and responsiveness, and has scores ranging from 0–16. Minimal important difference was a 3-point reduction and clinically meaningful change was a 5-point reduction. Severity thresholds for HiSQOL-mini score were 0 for ‘none’, 1–2 for ‘mild’, 3–4 for ‘moderate’, 5–6 for ‘severe’ and 7–16 for ‘very severe’. Conclusions HiSQOL-mini, using the same item format as HiSQOL, contains four items relating to ‘pain’, feeling ‘down or depressed’, ‘walking’ and ‘getting dressed’. HiSQOL-mini is a valid, reliable and responsive questionnaire to measure health-related QOL in patients with HS and should be swift to perform.