Table 4.

Association of knowledge and attitude related factors with initiation of HPV vaccination (N = Total numbers of subjects with valid data under each category of answer)

	Intention/Action stage #	Pre-contemplation/Contemplation stage #	Mean difference [95% CI]	P value
Mean knowledge score (N = 1343)	3.52	3.33	0.18 [0.01-0.37]	P = 0.04*
I think that Cancer is a terrifying disease (N = 1409)	5.11	4.97	0.147 [0.01-0.285]	P = 0.04*
If I know any ways which can prevent cancer, I am willing to change in an attempt to put them into practice (N = 1409)	4.56	4.4	0.17 [0.03-0.3]	P = 0.02*

#No statistical significance in mean knowledge score between the two stratified groups was found for agreement to the following statements: I think schools should provide more information on cancer to enhance the knowledge of students, I think that Hong Kong has provided adequate services in promoting prevention of cancer and I wish to have more information on cancer prevention.

*= P value with statistical significance.