TABLE 2.

Association of Subject Characteristics With the Primary and Restrictive Outcomes Regardless of Intervention Group Adjusted for Clustering by Recruitment Center

	Primary	Restrictive
	Outcomea	Outcome
Age, y, %
<15	44.2	11.1
≥15	29.0	5.4
	P < .001	P < .001
Sex, %
Male	33.2	7.1
Female	39.0	8.8
	P = .01	P = .11
Race and ethnicity, %
Non-Hispanic white	36.3	7.5
Non-Hispanic African American	37.0	8.5
Hispanic	35.2	8.5
Other	35.3	6.8
	P = .80	P = .94
BMI, %
Normal	37.8	7.9
Overweight or obese	34.3	8.2
	P = .14	P = .21
Passed out or nearly passed out from shot or blood draw in  the past 5 y, %
No	35.4	7.5
Yes	47.8	15.1
	P = .009	P = .02
Hunger or thirst at the time of enrollment, %
Not at all or a little bit	35.3	7.2
Very	39.2	10.9
	P = .13	P = .02
Tired at the time of enrollment, %
Not at all or a little bit	35.6	7.8
Very	40.1	13.9
	P = .36	P = .07
Prevaccination anxiety, %
None or slight	33.9	6.3
Mild, moderate, or severe	40.8	11.5
	P = .004	P < .001
No. of injectable vaccines,​b %
1	30.6	5.2
>1	43.7	11.8
	P < .001	P < .001
Receipt of HPV vaccine, %
No	33.8	7.3
Yes	38.3	8.5
	P = .02	P = .11
Pain intensity after vaccination, %
0–1	31.9	5.1
2–5	62.0	26.1
	P < .001	P < .001

^aThe primary outcome is “a little bit” or more in response to any of the 12 items on the presyncope instrument. The restrictive outcome is “somewhat” or more in response to any of the 12 items on the presyncope instrument.

^bIncluding intramuscularly and subcutaneously administered vaccines.