Table 4.

fMRI data at 3 Months vs cognitive outcomes at 12 months: elastic net regression results

Outcome	Null model prediction error	FMRI prediction error
Trails B	14.7	14.6 (95% CI, 14.4–14.8)
RBANS	15.5	15.5 (95% CI, 15.3–15.6)

Elastic net is a variant of linear regression that allows principled use of many more predictors than observations, as is the case here where we predict outcomes in patients using fMRI signals from approximately 30 000 brain voxels. Functional MRI images acquired at 3-month follow-up did not predict cognitive outcomes on RBANS and Trails B tasks at 12 months. The null model (which assumes all patients had the same outcome) predicted, for example, 12 month Trails B with an error of 14.7 points. Adding fMRI data to the linear model did not significantly improve the prediction of Trails B compared with the null model (error of 14.6 points).

CI indicates confidence interval.