Comparative Analysis of Skincare Regimens on Post-Acne Scars Outcomes

Thesis Abstract

This study investigates the comparative effectiveness of three commonly used skincare regimens on the outcomes of post-acne scarring, addressing the gap in evidence on regimen-specific performance across diverse populations. The problem centers on inconsistent real-world results regarding scar improvement, variability in patient adherence, and limited head-to-head comparisons of regimens combining topical agents, moisturizers, and adjunctive modalities. The aim is to determine which regimen yields superior scar improvement, higher patient satisfaction, and better safety profiles over a 24-week period. Specific objectives include (1) to compare changes in scar severity using the Goodman and Barrow Post-Acne Scar Scale across regimens; (2) to evaluate patient-reported outcomes including satisfaction, perceived texture, and quality of life via the Dermatology Life Quality Index; (3) to assess time-to-improvement and durability of effects through weekly monitoring and a follow-up assessment at 12 weeks post-intervention; (4) to identify adherence patterns and their association with outcomes; and (5) to examine whether baseline scar type (macular, atrophic, or hypertrophic) moderates regimen effectiveness. The study tests the null hypothesis that there are no differences among regimens in scar improvement, with sensitivity analyses to account for confounders such as age, sex, skin phototype, and concomitant therapies; and exploratory analyses guided by the Health Belief Model and Self-Efficacy Theory to interpret adherence-related variation. Methodologically, the research adopts a randomized controlled, multi-arm parallel design with 240 adult participants aged 18–45 presenting stable post-acne scarring recruited from dermatology clinics in three metropolitan centers. Participants are stratified by scar type and phototype and randomly assigned to one of three skincare regimens Regimen A (topical retinoid plus tranexamic acid serum and broad-spectrum sunscreen), Regimen B (cryptic combination of azelaic acid, vitamin C, niacinamide, and moisturizer with a physical sunscreen), and Regimen C (peptide-rich antioxidant serum, glycolic acid 10% weekly, and silicone-based scar gel). Data collection instruments include standardized photographic scar assessments, the Goodman and Barrow scale administered by blinded evaluators, high-resolution skin imaging analyzed with digital scar quantification software, the Dermatology Life Quality Index, and a validated regimen adherence questionnaire. Instrument validity and reliability are established through pilot testing (n=20) and Cronbach’s alpha for multi-item scales (>0.80). Data analysis utilizes mixed-effects repeated-measures ANOVA to compare longitudinal outcomes across groups, with post-hoc pairwise comparisons adjusted by Bonferroni correction. Multivariate regression models assess the influence of baseline scar type and phototype on treatment response, while Kaplan–Meier analysis evaluates time to clinically meaningful improvement. A per-protocol analysis complements the intention-to-treat approach to gauge the impact of adherence. The theoretical framework integrates the Health Belief Model to interpret perceived barriers and benefits influencing regimen adherence and the Self-Determination Theory to explain intrinsic motivation toward sustained skincare routines. The anticipated findings include Regimen B delivering the greatest average reduction in scar severity scores at 24 weeks, Regimen A achieving notable improvements in patient-reported texture and visibility, and Regimen C providing significant gains in antioxidant-related outcomes with acceptable tolerability. It is expected that adherence will be positively correlated with magnitude of improvement across all regimens, with stronger effects in users with lighter skin phototypes due to photoprotection considerations. The study contributes to knowledge by providing rigorous, comparative, real-world evidence on the relative effectiveness and safety of common skincare regimens for post-acne scarring, informing clinical decision-making, patient counseling, and guideline development. Clinically, findings will guide regimen selection based on scar type, patient preferences, and adherence potential, while policy implications address access to comprehensive skincare regimens and standardized outcome measures in dermatology research. The main conclusion anticipates that tailored regimens combining hydration, active agents (retinoids or azelaic acid), and targeted scar-directed formulations yield superior outcomes, with regimen selection optimized by baseline scar characteristics and adherence determinants; recommendations emphasize individualized treatment plans, ongoing adherence support, and the integration of objective scar metrics into routine practice to enhance treatment monitoring and patient satisfaction.