Table 3.

Mean of delta (post-test time minus pre-test time, based on Wilcoxon sign rank test for paired data)

Type	Mean	Std. deviation	P
Off time of cases	4.5976	8.9607	<0.0001
On time of cases	−0.9566	10.7589	0.41
Total time of cases	3.6409	17.2987	0.013
Off time of controls	−1.0144	8.7518	0.071
On time of controls	−3.7834	8.2791	0.001
Total time of controls	−4.7979	12.8052	0.006