OBJECTIVES:

Assess the psychometric properties of the electronic Hidradenitis Suppurativa (HS) Symptom Daily Diary (eHSSDD) and HS Symptom Questionnaire (eHSSQ), developed to capture core participant-perceived HS symptoms.

METHODS:

Pooled, blinded data from participants with moderate-to-severe HS enrolled in the phase 3 BE HEARD I (NCT04242446) and II (NCT04242498) trials were analyzed (eHSSDD: N=934; eHSSQ: N=1,007). Average weekly scores (if ≥4/7 daily scores non-missing) were derived for the 5 eHSSDD items; simulation analyses were conducted to confirm this rule. Test-retest reliability was evaluated using intraclass correlation coefficients (ICCs) between baseline and Week (Wk) 4 (eHSSDD), or Wk32 and Wk36 (eHSSQ). Convergent/divergent validity was assessed between the eHSSDD and eHSSQ compared with relevant patient-reported outcomes (PROs; Dermatology Life Quality Index [DLQI], HS Quality of Life Questionnaire symptom subscale) and clinician-reported outcomes (ClinROs; International HS Severity Score System [IHS4], derived programmatically post-collection) at baseline and Wk16. Known-groups validity was assessed, comparing eHSSDD and eHSSQ scores between participant subgroups pre-defined using PRO/ClinRO measures (Patient Global Impression [PGI] of HS severity, Hurley Stage, IHS4, HS Physician’s Global Assessment [derived programmatically]). Responsiveness was evaluated by correlating changes from baseline to Wk16 in eHSSDD and eHSSQ scores with changes in PGI scales.

RESULTS:

At Wk16, eHSSDD and eHSSQ completion rates were 70.1% and 90.2%, respectively. Simulation analyses confirmed the appropriateness of the eHSSDD weekly scoring rule. Test-retest reliability analyses demonstrated good score reproducibility (ICC: eHSSDD: 0.80–0.86; eHSSQ: 0.73–0.84). Correlations between eHSSDD and eHSSQ scores and other PROs and ClinROs were generally consistent with predefined hypotheses, indicating good convergent/divergent validity. eHSSDD and eHSSQ scores discriminated between pre-defined subgroups at Wk16, confirming known‑groups validity. 16-wk changes from baseline in eHSSDD and eHSSQ scores and anchors were moderately-to-strongly correlated (>0.30), establishing responsiveness.

CONCLUSIONS:

eHSSDD and eHSSQ scores demonstrated good reliability, validity, and responsiveness in participants with moderate-to-severe HS.