Table 2.

Summary of the generalized linear mixed-effects model of risk for a voxel to convert into white matter hyperintensities at follow-up with baseline nFA (M1) strata or baseline nFA and nFL (M2) strata as main factorsa

OR (95% CI)POR (95% CI)P
    0.9∼11.25 (1.05–1.49)0.00151.13 (1.01–1.28).0075
    0.7∼10.91.39 (1.17–1.67)<.0011.31 (1.16–1.47)<.001
    <.71.51 (1.26–1.81)<.0011.45 (1.28–1.64)<.001
    0∼13.06 (2.59–3.61)<.001
    1∼225.51 (21.66–30.05)<.001
    2∼3223.28 (189.39–263.25)<.001
    3∼4680.54 (574.31–806.41)<.001
    4∼5954.33 (778.96–1169.19)<.001
  • Note:—CI indicates confidence interval; N/A, not applicable.

  • a Entries show the OR with the reference (Ref) groups being, respectively, the lower and the higher stratum for nFA (>1) and nFL (−1∼0), followed by the associated 95% CI and P value of the t test, adjusted for multiple comparisons. Normalized FA measures were obtained by creating FA maps of each subject by dividing each voxel by the mean FA map of the young sample at that voxel location. Normalized FLAIR measures were obtained for each individual by z scoring original FLAIR signal intensities in the normal WM mask.

  • b Quartiles of normalized FA.

  • c SD units.