Table 1: Mean and Standard deviation scores of saying "no" skill between the intervention and the control group before, immediately and two months after the intervention.

Stage	Group	Number	Mean	Standard deviation	T value	Degree of freedom	p-value
Before intervention	control	73	2.0685	1.05842	1.835	143	0.06
	intervention	72	1.7500	1.03120
Immediately after the intervention	control	73	1.7534	0.98292	-14.996	143	0.000
	intervention	72	3.6944	0.49330
Two months after the intervention	control	73	2.0822	0.95384	-10.776	143	0.000
	intervention	72	3.5139	0.60498