Table 2.

Correlates of Effect Size (Difference in HPV Vaccine Initiation between Minority and White)

HPV VACCINE INITIATION		n	k	Effect Size	I²	Difference	P
All studies		1,751,281	94	0.0% [-1.8%,1.8%]	98	-	-
Correlate
Publication Year	2009–2010	557,222	25	−3.0% [−6.4%,0.3%]	92	ref	-
	2012–2014	248,137	40	−0.3% [−2.9%,2.4%]	97	2.8%	0.20
	2015–2017	945,922	29	2.9% [−0.1%,6.0%]	97	6.0%	0.01
Sampling of Clusters	National	1,430,561	60	−0.2% [−2.5%,2.1%]	98	ref	-
	Regional/Single Site	320,720	34	0.1% [−2.7%,2.9%]	98	0.3%	0.88
Sampling of Individuals	Probability	1,369,523	43	1.0% [−1.8%,3.8%]	98	ref	-
	Convenience	381,758	51	−0.8% [−3.1%, 1.5%]	98	−1.8%	0.34
Sex	Female	922,842	80	−1.6% [−3.5%,0.4%]	97	ref	-
	Male	828,439	26	7.1% [3.9%,10.3%]	99	8.7%	<.001
Age Included (years)	Under 18 only	1,201,965	35	4.3% [1.7%,6.9%]	98	ref	-
	Includes 18+	549,316	65	−2.5% [−4.6%, −0.4%]	97	−6.8%	<.001
Source of Race and Ethnicity Data	Self-Report	448,820	79	−1.3% [−3.2%,0.6%]	97	ref	-
	Administrative	1,302,461	15	5.5% [1.5%,9.5%]	99	6.8%	0.003
Source of Vaccination Data	Self-report	264,260	64	−3.6% [−5.5%, −1.7%]	95	ref	-
	Provider-verified	1,487,021	30	6.0% [3.6%,8.5%]	99	9.6%	<.001
NIS—Teen Data	No	1,604,353	85	−1.1% [−2.9%,0.6%]	98	ref	-
	Yes	146,928	9	7.9% [3.3%, 12.5%]	98	9.0%	<.001

HPV VACCINE FOLLOW-THROUGH
All studies		355,044	41	−9.6% [−12.1%, −7.1%]	96	-	-
Correlate
Publication Year	2009–2010	169,326	12	−15.1% [−18.9%, −11.2%]	92	ref	-
	2012–2014	42,228	12	−6.6% [−10.8%, −2.5%]	90	8.4%	0.004
	2015–2017	143,490	17	−6.5% [−10.0%, −3.0%]	90	8.6%	0.001
Sampling of Clusters	National	294,758	28	−10.5% [−13.6%, −7.5%]	97	ref	-
	Regional/Single Site	60,286	13	−7.7% [−12.1%, −3.3%]	93	2.8%	0.30
Sampling of Individuals	Probability	291,971	26	−9.7% [−13.0%, −6.5%]	97	ref	-
	Convenience	63,073	15	−9.4% [−13.5%, −5.4%]	94	0.3%	0.91
Sex	Female	259,774	39	−9.4% [−11.9%, −6.8%]	96	ref	-
	Male	95,270	10	−5.7% [−10.9%, −0.6%]	87	3.6%	0.22
Age Included (years)	Under 18 only	163,432	16	−8.0% [−11.8%, −4.2%]	95	ref	-
	Includes 18+	191,612	27	−10.9% [−14.0%, −7.7%]	95	−2.9%	0.25
Source of Race and Ethnicity Data	Self-Report	71,130	23	−10.0% [−13.4%, −6.5%]	93	ref	-
	Administrative	283,914	18	−9.2% [−13.0%, −5.5%]	98	0.8%	0.77
Source of Vaccination Data	Self-report	7,817	9	−13.7% [−19.3%, −8.1%]	74	ref	-
	Provider-verified	347,227	32	−8.6% [−11.4%, −5.9%]	97	5.1%	0.11
NIS—Teen Data	No	299,188	33	−10.6% [−13.4%, −7.7%]	96	ref	-
	Yes	55,856	8	−6.3% [−11.5%, −1.2%]	96	4.2%	0.16

Note. Effect size is the difference in HPV vaccine initiation between minority and White. Negative numbers indicate a disparity, minorities had lower HPV vaccination coverage than Whites; positive numbers indicate a reverse disparity. NIS—Teen = National Immunization Survey—Teen.