Anna Rozenshtein MD, Presenter: Nothing to Disclose

Gregory D. N. Pearson MD, PhD, Abstract Co-Author: Nothing to Disclose

Sherry Yan, Abstract Co-Author: Nothing to Disclose

Andrew Zhangyanchu Liu BS, Abstract Co-Author: Nothing to Disclose

Radiology curricula are based on lectures, typically with uninterrupted repetition (massing) of similar cases. Educational research reveals that spacing intellectual activity by mixing (interleaving) items-to-be-learned leads to better recollection of items already seen as well as better induction (pattern recognition). We compare the effectiveness of massed vs. interleaved methods of teaching chest x-ray interpretation.

After IRB approval, we recruited 40 medical students (average age 23, 33% women, 60% in the first and 40% in the second year of training) without formal radiology training, and randomized them into two groups matched in age, gender, and year of training. Each group was shown a recorded presentation with six examples each of normal radiograph, bronchiectasis, miliary disease, pneumothorax, lung mass, emphysema, pleural effusion, pneumonia, atelectasis, congestive heart failure, pulmonary fibrosis, and mediastinal mass, each with an independent voiceover imbedded with the slide. At the start both groups saw six consecutive normal chest radiographs. The “massed” group saw the remaining 66 images in 11 consecutive blocks, each consisting of six images of the same disease entity. The “interleaved” group saw the same images in three blocks of 22 randomized images (two images of each pattern per block) to avoid repeating diseases by chance. After a distracting activity and a snack, a multiple choice test with 24 chest x-rays, two in each pattern, was administered. One of these images was previously shown, testing recollection. The other was new, testing induction. Statistical analysis was performed using Student’s t-test of proportion.

The average test score was 47.4% ± 21.8% for women and 51.4% ± 18.6% for men (p = 0.58), 39.1% ± 14.4% for the first year and 66.7% ± 13.3% for the second year students (p= 0.000000592). The interleaved group scored overall 57.1% ± 17.1%, compared to the massed group 43.1% ± 19.7% (p = 0.03). Comparing the interleaved and the massed groups, average scores on recall were 61±17.5% vs 46.7± 18.8% (p = 0.03) and on induction 53.3±20.8% vs. 40.4±23.4% (p=0.1). 

Interleaving different pathologies in a short medical student traning session led to improved image recognition compared to the massed method  

In a short training session mixing, rather than massing teaching cases led to better learning of radiographic patterns of disease.

Rozenshtein, A, Pearson, G, Yan, S, Liu, A, The Effects of Spacing in Radiology Instruction: Are Orderly Lectures Really Better than Messy Case Conferences?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14002540.html