Lacher, D.A.; Richardson, B.L. Predicting First-Year Medical
School Performance From MCAT Scores and Premedical Grade-Point Average
Using Neural Networks. Paper presented at the Research in Medical
Education Conference; October 1994. Boston, Mass.
PURPOSE: This study was designed to compare neural networks
and multiple linear regression approaches in their ability to predict
medical school performance and the selection of significant predictor
variables.
METHODS: Performance measures consisted of grades and a
cumulative first-year scores for 107 medical students. The independent
variables included in the study were undergraduate GPA and MCAT
scores. Multiple linear regression and back propagation neural network
analyses were performed. The authors developed a back propagation
neural network consisting of 7 input neurons, 5 hidden neurons,
and one output neuron for the first-year medical school grades.
Cross-validation was accomplished by selecting 85 (80%) students
on which to develop the regression equation and neural network and
subsequently predicting the grades of the remainng 22 (20%) students.
RESULTS: When all input variables were used, the neural
network predicted grades (R=0.75) better than multiple linear regression
(R=0.64). Stepwise multiple linear regression selected the science
GPA and MCAT Biological Sciences score as the best predictor variables
while neural network sensitivity analysis revealed that the total
GPA and the Writing Sample scores were the best predictor variables.
Cross-validation analysis revealed that multiple linear regression
gave more consistent predictions of first-year performance (R ranged
from 0.62 to 0.73) than neural networks (R ranged from 0.38 to 0.68).
CONCLUSIONS: The authors concluded that their findings indicated
neural networks better predicted medical school grades than did
multiple linear regression but were less consistent in cross-validation
analysis. Additionally, they determined that each type of analysis
identified different variables as being most valuable in predicting
first year medical school grades.
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