Investigating the Impact of Peer Influence on Academic Performance: A Quantitative Cross-Sectional Study Among Medical Students

Background: A peer group consists of individuals of similar age, socioeconomic status, and ability, significantly influencing behaviors and beliefs, including academic success. Peer influence can be positive, facilitating social learning and class participation, or negative, leading to behavioral disengagement, anxiety, and decreased academic performance. Recent studies indicate that peer relationships account for 28% to 39% of the variance in the academic performance of medical students. Objectives: This study investigates the impact of peer influence on the academic performance of medical students and examines the roles of peer relationships and learning engagement as potential factors in this association. Methods: This cross-sectional study was conducted at a public sector medical university in Lahore, Pakistan, over six months (February 2024 - September 2024) and approved by the institutional review board. A sample size of 176 MBBS students was calculated with a 95% confidence level and 90% test power, with an anticipated effect size of 0.262 based on previous literature. Data were collected using two validated instruments: the Peer Group Influence Achievement Questionnaire (13 items, Cronbach's α = 0.85) and the Peer Relationship and Learning Engagement Scale (9 items, Cronbach's α = 0.79). Academic performance was assessed through professional examination scores categorized as below average (<60%), average (60-75%), and above average (>75%). Data were analyzed using descriptive statistics and Pearson's chi-square test, with p<0.05 considered significant. Results: Among 176 participants (response rate: 85%), the majority were aged 21-23 years (73.9%, n=130) with a female predominance (76.1%, n=134). Chi-square tests revealed significant relationships between peer influence and academic performance (χ²=11.087, df=4, p=0.026, Cramer's V=0.178) and between learning engagement and academic performance (χ²=10.869, df=4, p=0.028, Cramer's V=0.176). Moderate to strong peer influence was reported by 98.3% of participants. However, factorial ANOVA showed a non-significant interaction between peer influence and peer relationships regarding academic performance (F=0.751, p=0.523, η²=0.009). Conclusion: Peer influence significantly impacts the academic performance of medical students, and learning engagement is also significantly related to academic performance. However, the quality of peer relationships does not moderate the relationship between peer influence and academic performance. These findings suggest a need for structured peer-support programs in medical education. Future research should explore the longitudinal effects of peer influence on academic trajectories.