External Validation of the IHS4-55 in a European Antibiotic-Treated Hidradenitis Suppurativa Cohort

Abstract

Background: Previously, a new dichotomous outcome was developed, calculated as 55% reduction in the International Hidradenitis Suppurativa 4 score (IHS4-55). It was validated in datasets of adalimumab and placebo treated HS patients. External validation is an important aspect of clinical outcomes. Objectives: We aimed to externally validate the novel dichotomous IHS4-55 in a non-biologic treated dataset of HS patients. Methods: Data from a previously published European-wide prospective clinical study of antibiotic treatment of HS patients was used to assess the association of IHS4-55 achievement with individual reduction in inflammatory nodules, abscesses and draining tunnels. Moreover, the associations between IHS4-55 positivity and achievement of the minimal clinically important differences (MCID) for Dermatology Life Quality Index (DLQI), numerical rating scale (NRS) Pain, and NRS Pruritus were analyzed. Results: Data was obtained from 283 individual patients, of which 36.4% (103/283) were treated with clindamycin and rifampicin and 63.6% (180/283) with tetracyclines for 12 weeks. Achievers of the IHS4-55 demonstrated a significant reduction the counts of inflammatory nodules, abscesses, and draining tunnels (all p<0.001). Additionally, IHS4-55 achievers had an odds ratio (OR) for achieving the minimal clinically important difference (MCID) of DLQI, NRS Pain and NRS Pruritus of 2.16 (95% CI 1.28-3.65, p<0.01), 1.79 (95% CI 1.10-2.91, p<0.05), and 1.95 (95% CI 1.18-3.22, p<0.01), respectively. Conclusions: This study shows the external validity of the novel IHS4-55 by demonstrating a significant association between IHS4-55 achievement and a reduction in inflammatory lesion counts as well as achievement of MCIDs for DLQI, NRS Pain and NRS Pruritus in an antibiotic-treated cohort. These findings support the use of the IHS4-55 as a novel primary outcome measure in clinical trials.

Anti‐IL17 Secukinumab in hidradenitis suppurativa: A long‐term drug survival analysis

“…Thirdly, the newly developed scoring system, IHS4‐55, which was created to overcome the limitation of HiSCR in patients with an abscess‐nodular count (AN) <3 accompanied by numerous draining tunnels, exhibits comparable discriminatory efficacy to HiSCR in capturing the optimal treatment response (Supplementary S2). 17 In our series, this phenomenon was observed 6 months into the therapy, despite displaying a slower rate of change during the initial 3 months of treatment. At last, there was only a modest impact on the improvement of patients' quality of life, with a mild benefit not reaching statistically significance.…”

Impact of Single Nucleotide Polymorphisms of the Promoter of the TNF Gene on Adalimumab Treatment Responses in Hidradenitis Suppurativa

“…All respective comparisons for the relative changes of IHS4 score, AN and dT counts from baseline were done by the Student’s t test. A 55% or more decrease in the baseline IHS4 has recently been suggested as an alternative efficacy endpoint [8, 9]. Comparisons for this endpoint were done by the Fisher’s exact test.…”