In clinical research, particularly in the study of hidradenitis suppurativa (HS), the evaluation of treatment efficacy is of paramount importance. This article provides a comprehensive overview of the 3 most commonly used clinical outcome assessments (COAs) in HS trials: the HS Clinical Response (HiSCR), the HS Quality of Life (HiSQOL), and the Hurley Stages of HS. These tools offer a robust and quantifiable approach to assessing the severity, extent, and impact of HS on patients’ quality of life. We will explore the specifics of each assessment tool, elucidating their methodologies and significance in the context of HS research.
1. HS Clinical Response (HiSCR)
HiSCR entails a meticulous count of inflammatory nodules and abscesses. It classifies a dichotomous response characterized by a minimum of 50% improvement in the sum of the abscess and inflammatory nodule count (AN Count) relative to baseline, with no increase in the number of abscesses or draining fistulas from baseline.
2. HS Quality of Life (HiSQOL)
The HiSQOL is a patient reported outcome (PRO) employed to evaluate symptoms related to HS and assess the impact and changes of HS effects on the quality of life. The HiSQOL questionnaire is a 17-item questionnaire scored from 0 to 68 with domains for symptoms, activity-adaptation, and psychosocial impact with higher scores representing a more severe disease impact.
3. Hurley Stages of HS
The investigator will ascertain the Hurley Stage for each affected anatomical region. In cases where more than one stage is present in a region, the worst stage in each area must be documented. The participant is allocated the Hurley Stage corresponding to the worst involved anatomical region.
Table 1. Key HS Top 3 COA Characteristics
| Instrument/ Assessment | Global Assessment | ClinRo | PRO | Validated in Adults | Validated in Children/ Adolescent | License Requirement | References |
| HiSCR | ✔ | ✔ | Yes | Kimball 2014 | |||
| HiSQOL | ✔ | ✔ | Yes | Kirby 2020 | |||
| Hurley Stage | ✔ | No | Jemec 2012 |
Conclusion
To conclude, the tools explored in this article are crucial for evaluating treatment and understanding the impact of HS on patients’ quality of life. The HiSCR offers a quantifiable approach to assessing the severity of HS, while the HiSQOL measures the disease’s effects on patient’s daily lives. The Hurley Stages of HS provide a comprehensive view of the disease’s extent in each affected anatomical region. To explore further insights into measuring disease activity and response in trials for HS, refer to the webinar “Spotlight on HS” which was recorded for the occasion of the Innovaderm AAD Breakfast event, where Dr. Garg, Dr. Kimball and Dr. Krueger shared their expertise.
About the author
A seasoned scientist and medical writing expert, Teresa is dedicated to fostering scientific engagement and enhancing the strategic value of medical affairs and innovation in clinical trials. She seamlessly navigates her roles with a decade-long background in preclinical research across various therapeutic areas.

