Table 4.

Differences in the amplitudes of waves I, III, and V between the case group after 1 year and the case group at the start of the experiment and the control group

Amplitude	Post	Pre			P value‡
	Case	Case	P value†	Control
Wave I
Mean±SD	0.19±0.04	0.2±0.08	0.006	0.17±0.11	0.013
Median (range)	0.16 (0.05 to 0.38)	0.2 (0.07 to 0.46)		0.16 (0.02 to 0.9)
Wave III
Mean±SD	0.49±0.13	0.55±0.14	<0.001	0.29±0.1	<0.001
Median (range)	0.47 (0 to 0.83)	0.55 (0 to 0.87)		0.32 (0.1 to 0.45)
Wave V
Mean±SD	0.45±0.12	0.53±0.2	<0.001	0.21±0.14	<0.001
Median (range)	0.45 (0 to 0.89)	0.53 (0 to 0.89)		0.18 (0.08 to 0.9)

^†Based on the paired t test;

^‡Based on the t test