Development and validation of patient-reported outcome measures for platysma prominence.

Background: Platysma prominence (PP) is characterized by vertical bands along the length of the neck and blunting of the jawline, impacting aesthetic appearance. No validated patient-reported outcome (PRO) measures are available to assess patient experiences specific to PP.

Objective: Develop and validate fit-for-purpose PRO measures that capture patient experiences with PP and treatment outcomes.

Methods: PRO measures were developed and validated in alignment with the FDA's patient-focused drug development guidance. Three interviews (concept elicitation [CE], N = 30; cognitive debriefing [CD] round 1, N = 20; round 2, N = 5) were conducted with treatment-naive and previously treated adults with PP. Instruments were drafted based on concepts emerging from CE interviews. Psychometric testing for reliability and validity was conducted using phase 2 PP treatment study (ClinicalTrials.gov; NCT03915067) data (N = 164). While there were no available gold standard measures, convergent and known-groups validity were assessed using multiple FACE-Q modules, the Participant Global Impression of Severity (PGIS)-Jawline, and the Participant Global Impression of Treatment Satisfaction (PGI-TS). The 2-way random intraclass correlation coefficient ICC(2,1) and R_λ were calculated to evaluate test-retest reliability. Values of ≥0.70 were considered success for both the ICC(2,1) and R_λ. Spearman correlations (ρ) between scores from draft instruments and co-validators were used to assess convergent validity (|ρ|≥0.40). Additionally, internal consistency reliability was examined for multi-item measures where Cronbach's α ≥ 0.70 was considered success.

Results: "Bands" or a variation (e.g., cords, ridges, lines) were the most common terms used to describe PP, reported by 50% of participants. The most frequently reported psychosocial impacts were looking older than desired (n = 28, 93.3%), feeling self-conscious (n = 24, 80.0%), feeling less attractive (n = 20, 66.7%), and looking less attractive and dressing differently (both: n = 19, 63.3%). Reduced platysma band prominence was the most cited change that would increase satisfaction (n = 15, 50.0%). Following CE interviews, 3 PRO measures were drafted: Appearance of Neck and Lower Face Questionnaire (ANLFQ): Impacts, ANLFQ: Satisfaction (Baseline/Follow-up), and the Bother Assessment Scale-Platysma Prominence (BAS-PP). CD interviews indicated that participants found the questionnaires understandable and relevant. In psychometric testing, established criteria for reliability and validity were predominantly met, with some exceptions. Three correlations were under the 0.40 threshold, and while these correlations were all in the expected direction, their smaller magnitudes were not unexpected given the restricted conceptual alignment between the PP PROs and co-validating measures.

Conclusion: These PRO measures demonstrated content and psychometric validity and are ready for use in research and practice to better understand the impact of PP from the patient perspective.