Importance: Treatment satisfaction is important to achieving therapeutic success in patients with inflammatory dermatological diseases, such as acne.
Objective: To evaluate the structural validity, internal consistency, and construct validity of the DermSat-7, a questionnaire-based measure of treatment satisfaction, in patients with acne seen in routine clinical practice.
Design, setting, and participants: This cross-sectional study included adults with acne who were fluent in English and treated at an outpatient clinic at Brigham and Women's Hospital between July 2022 and May 2023. At each visit, patients completed a self-administered, patient-reported outcome questionnaire, including a patient global assessment (PGA) of their acne severity and the DermSat-7. The DermSat-7 consists of 7 items assessing 3 domains of treatment: effectiveness (3 items), convenience (3 items), and overall satisfaction (1 item). At subsequent visits, patients were asked an anchor item related to change in disease severity ("How has your acne changed compared to your last visit?") that was scored on a 7-point scale (-3 = much worse to 3 = much better). Also at each visit, a dermatologist completed the Comprehensive Acne Severity Scale (CASS).
Main outcomes and measures: The main outcomes were structural validity (assessed by factor analysis), internal consistency (assessed by Cronbach α), and construct validity (assessed using linear regression models and Pearson correlation coefficients).
Results: The analysis included 142 patients with acne (mean [SD] age, 25.1 [5.1] years; 96 females [67.6%]) taking acne medication who completed the DermSat-7. Exploratory factor and confirmatory factor analysis supported the unidimensionality of the 3 DermSat-7 domains. Cronbach α values of 0.89 and 0.80 supported good internal consistency in the effectiveness and convenience domains, respectively. Known-groups validity was supported by increasing DermSat-7 effectiveness and overall satisfaction scores with increasing levels of positive change in disease severity (linear regression coefficient, 7.51; 95% CI, 4.94-10.08; P < .001). Construct validity was further supported by moderate correlations with the anchor, PGA, and CASS scores (effectiveness domain: anchor r = 0.567, PGA r = -0.538, and CASS r = -0.485; overall satisfaction domain: anchor r = 0.467, PGA r = -0.486, and CASS r = -0.489).
Conclusion and relevance: This cross-sectional study found that the DermSat-7 may be an effective tool for measuring treatment satisfaction, particularly effectiveness and overall satisfaction domains, among patients with acne. Further research is needed to examine additional measurement properties of the DermSat-7, such as content validity and interpretability, as well as to validate the DermSat-7 in other populations of patients with acne.