Standardized extracurricular skills labs courses have been developed in recent decades and are important approaches in peer-assisted medical learning (PAL). To provide high quality training and achieve effective learning strategies, continuous evaluations and quality assessments are essential. This research aims to evaluate quality data from medical students participating in extracurricular skills labs courses at Ruhr-University Bochum to prospectively optimize concepts and didactical training and standardize processes. Additionally, we set out to assess and quantify drivers that are influencing factors of the self-reflection of competencies. The analysis was based on a routine assessment of n = 503 attendees of the PAL courses in the skills labs in three consecutive semesters, who voluntarily participated in the evaluation. We analyzed the effects of age, semester and their interaction on the self-reflection of competencies in technical skills courses using moderated regression and simple slope analyses, as previously published. A univariate analysis of variance (ANOVA) with post hoc Tukey HSD testing was used to analyze group means in estimated competencies using IBM SPSS Statistics V.28. An analysis of variance revealed a significant increase in self-assessed competencies when comparing pre- vs. post-course evaluation data in all 35 depicted items (all p < 0.001). A total of 65.5% of the items were adjusted significantly differently, revealing modified self-reflected pre-course levels compared to those stated before. A moderated regression analysis revealed that age (R2 = 0.001, F(1;2347) = 1.88, p < 0.665), semester of study (∆R2 = 0.001, ∆F (1;2346) = 0.012, p < 0.912) and their interaction (∆R2 = 0.001, ∆F (1;2345) = 10.72, p < 0.227) did not explain a significant amount of the variance in self-reflection variance. A simple slope analysis of earlier (b = 0.07, t = 0.29, p < 0.773) and later semesters of study (b = 0.06, t = 0.07, p < 0.941) did not differentiate from zero. The presented evaluation paradigm proved to be a useful tool to encourage students to initiate self-regulatory and self-reflective behavior. The cohesive evaluation of the large cohort of attendees in extracurricular, facultative skills labs courses was helpful in terms of quality assessments and future adaptations. Further evaluation paradigms should be implemented to assess other influencing factors, such as gender, on self-reflection, since age and semester did not explain significant differences in the model.