In this study, we analyzed the relationship between TBL and final examination performance in a first- (ID) and second- (WH) year course to see how prior experience with TBL influenced later TBL performance. We found that final examination and iRAT scores were significantly higher in the second-year WH course as compared to the first-year ID course (Table 1). Average ID iRAT scores were highly correlated with ID and WH final examination scores, but more importantly, WH iRAT scores correlated with ID average iRAT scores, demonstrating consistent TBL performance between the two courses (Table 2). Because the WH TBL exercises only reviewed STI-related material, which was also covered by the third ID TBL exercise, we examined the relationship between iRAT scores in these two TBL exercises and found a statistically significant positive correlation (Table 3). When examining differences between stronger and more poorly performing students in the WH course, we found that average ID iRAT and final examination scores were statistically correlated in students performing in both the upper and lower 25th percentiles on the WH course final examination. However, no significant correlation between WH iRAT and final examination scores was seen in these same students. Importantly, ID iRAT and WH iRAT scores were highly correlated only in students that performed in the upper 25th percentile in the WH course (Table 5), demonstrating more consistent TBL performance in more strongly performing students.
We found that prior experience with TBL may improve TBL iRAT scores as evidenced by significantly (p<0.01) higher iRAT scores in the second year WH course as compared to the first year ID course, suggesting that these students may have benefitted from prior TBL experience (Table 1). Interestingly, in contrast to another one of our studies where TBL disproportinatley helped students struggling with course content [9], both struggling and highly performing students saw improvement in their iRAT scores in the WH course (Table 4). For students performing in the upper 25th percentile in the WH course, WH final examination scores were also significantly higher than ID final examination scores, suggesting that these students generally perform better in the second year WH as compared to the ID course, potentially negating the effect of prior TBL experience (Table 4). However, students performing in the lower 25th percentile on the WH final examination did not have significantly higher WH final examination scores than ID final examination scores, and therefore, their higher WH iRAT scores could reflect the effect of prior experience with TBL (Table 4).
Not surprisingly, we found that more strongly performing students have more consistent TBL scores as seen by the high correlation between ID and WH iRAT scores (r=0.48, p<0.01; Table 5). The positive correlation between the iRATs in these two different courses are consistent with recent publications from our group that report a positive correlation between iRAT scores and overall course performance [9, 14]. In this study, it is likely that improved performance in the second year course is due to overall improvement in study habits and better student management of self-directed learning time [15].
We also found that iRAT scores were correlated with, and were therefore predictive of, final examination scores in more poorly performing students in the ID course but not the WH course (Table 5). This was likely due to the paucity of material covered by the WH TBL exercise as compared to the ID course where students participated in weekly TBL exercises each Monday of this four-week course. As we have found in previous studies, consistent weekly TBL exercises have the ability to identify struggling students early in the course to allow for early intervention to ameliorate performance [10]. Although we have reported a highly significant correlation between final examination and iRAT scores for all students in the first year ID course, this correlation was stronger in struggling students as compared to strong performers, highlighting the predictive value of this learning strategy for this population of students [10]. When less TBL exercises are used, such as in the WH course, this benefit is unfortunately lost. On the other hand, some may argue that extensive use of graded TBL exercises, with their associated assessments, may increase student anxiety unnecessarily [15]. Therefore, further investigation is needed to determine the optimal usage of TBL in pre-clinical medical school curricula.
Because this is a single institution study, there are some limitations in generalizability to other institutions. However, because our TBL format is very similar to that described by Michaelsen et al. [16] we feel that for those instiutions that follow this structure, these results could help to guide TBL implementation and use in pre-clinical curricula. Additionally, because of the nature of medical education research and the inability to alter curricula to create informative control groups, we were unable to have the ideal control group which would have consisted of students whose initial participation in TBL exercises occurred in the WH course. The lack of this control group also limits our ability to fully interpret the data generated.