The inter‐rater reliability of IHS4 corroborates its aptitude as primary outcome measurement instrument for large clinical studies in hidradenitis suppurativa.

The article discusses the inter-rater reliability of the International Hidradenitis Suppurativa Severity Scoring System (IHS4) as a primary outcome measurement instrument for large clinical studies in hidradenitis suppurativa (HS). The study involved 31 dermatology residents from 16 countries who evaluated 10 HS patients with varying disease severity. The results showed that the IHS4 had excellent inter-rater reliability among the raters, indicating its suitability for use in large clinical studies. However, the evaluation of HS lesions without weighting and the evaluation of inflammatory nodules and abscesses only led to reduced reliability. The article concludes that the IHS4 is a reliable instrument for assessing HS in clinical studies. [Extracted from the article]