Impact of Energy Drinks and Caffeine on Cognition, Stress, and Sleep During Examination: A Mixed-Methods Cross-Sectional Study From a Medical School in Mauritius

BACKGROUND: The consumption of caffeine-containing products such as coffee and energy drinks is highly prevalent among medical students, particularly during exams, due to their stimulating effects. The primary objective of the study was to assess the effect of energy drinks and caffeine consumption on cognitive performance, perceived stress, and sleep quality among medical students during examination periods in Mauritius. METHODS: An observational, cross-sectional, mixed-methods study was carried out at Sir Seewoosagur Ramgoolam Medical College, Mauritius, from November 12 to November 30, 2025, during the university examination phases. Quantitative data were collected via Google Forms (Google, Mountain View, CA) shared through the class WhatsApp group (Meta, Menlo Park, CA), while qualitative data were obtained through one-on-one interviews that were audio-recorded and manually transcribed. A convenience sampling technique was used to select the participants of the study. The data were entered and analyzed using SPSS version 31 (IBM Corp., Armonk, NY). The qualitative data were collected through one-on-one, face-to-face interviews conducted by the research team and were analyzed using NVivo 15 (Windows) software (QSR International, Melbourne, Australia). Braun and Clarke's six-step thematic analysis method was used for data analysis. The quantitative study design and reporting were done according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. RESULTS: A total of 69 students participated in the study, among whom 44 (63.8%) were females, and 25 (36.2%) were males. The mean age was found to be 21.67 ± 1.86 SD years. Consumption rates are high across all years, ranging from 65.5% to 84.2%. Higher daily intake (≥3 servings) is linked to a greater frequency of reported "caffeine crash" symptoms (55.6%), compared to moderate intake (one to two servings), where only 15.4% report such symptoms (p = 0.031). A higher percentage of caffeine consumers (42.0%) fall into the "High Stress" category compared to non-consumers (21.1%). Consuming caffeine after 6 pm is strongly associated with longer sleep onset latency (>30 minutes), reported by 64.0% of this group, compared to only 28.0% of those who stop consumption before 6 pm (p = 0 .009). A descriptive qualitative study was conducted with eight participants. Phenomenological thematic analysis was performed, which generated five themes as follows: academic influences, cognitive boosting, consumption patterns, sleep disruption, and risk-benefit perception. Each theme had different categories: exam pressure, perceived control, alertness, focus, productivity, and other variables. CONCLUSION: During the examination period, caffeine usage was common among medical students across the years. Consuming caffeine after 6 pm was strongly linked to longer sleep latency, indicating that the timing of consumption influences sleep outcome. Overall, sleep quality is low, emphasizing their susceptibility to low-quality sleep during exams, and higher perceived stress was linked to changes in confidence levels.