Assessing vaccine hesitancy and health literacy using a new Italian vaccine confidence index and a modified Italian medical term recognition test: A cross-sectional survey on Italian parents

Figures & data

Figure 1. Time-flow diagram of the two phases of the study.

Table 1. Study population characteristics.

Factors	N (%)
Gender of the parent
Female	601 (80.89%)
Male	142 (19.11%)
Age
<30	53 (7.13%)
30–34	141 (18.98%)
35–39	175 (23.55%)
40–44	203 (27.32%)
45–49	117 (15.75%)
>49	54 (7.27%)
Education
Elementary school	5 (0.67%)
Middle school	129 (17.36%)
High school	356 (47.92%)
Bachelor/Master degree	223 (30.02%)
Postgraduate education	27 (3.63%)
Unknown	3 (0.40%)
Occupation
Healthcare worker	43 (5.79%)
Non-healthcare worker	697 (93.81%)
Unknown	3 (0.40%)
Number of children
1	326 (43.88%)
2	337 (45.35%)
>2	80 (10.77%)
Vaccine status
All	677 (91.12%)
Partial	56 (7.54%)
No	10 (1.34%)
Vaccine intention
All	664 (89.37%)
Partial	71 (9.55%)
No	8 (1.08%)
Main source of information
Family	142 (19.10%)
Acquaintance and friends	77 (10.36%)
TV network	93 (12.52%)
Internet	180 (24.23%)
Social Networks	43 (5.79%)
Daily newspaper	39 (5.25%)
Magazines	36 (4.85%)
General practitioner	637 (85.73%)
Health institutions	113 (15.21%)
Other	47 (6.33%)

Figure 2. Parallel analysis. The values reported on the x-axis represent the factor number to be included in the analysis while on the y-axis the values of eigenvalue.

Figure 3. Confirmatory analysis with 3-factors solution and item allocation by factor.

Table 2. Confirmatory factor analysis standardized coefficient weights for 9-item scale.

Correlation	Confidence	Hesitancy	Anxiety
	Std Coef. (CI 95%)	Std Coef. (CI 95%)	Std Coef. (CI 95%)
L1. Vaccines expose your children to the risk of serious side effects	–	0.584 (0.527; 0.642)	–
L2. You consider vaccines important for your child	0.781 (0.740; 0.822)	–	–
L3. Vaccines are effective	0.791 (0.751; 0.832)	–	–
L4. Often the serious side effects due to vaccines are kept hidden	–	0.748 (0.702; 0.793)	–
L5. Children are given excessive vaccinations at the same time	–	0.648 (0.596; 0.701)	–
L7. It causes you anxiety to get your child vaccinated	–	–	1.000
L.8 You support the introduction of mandatory vaccination to attend schools	0.598 (0.543; 0.652)	–	–
L9. Achieving full vaccination coverage of the population (over 95%) is necessary to protect younger children and weaker people who cannot be vaccinated	0.589 (0.533; 0.644)	–	–
L10. Childhood vaccines are above all an economic business for pharmaceutical companies	–	0.625 (0.570; 0.679)	–

Table 3. Association between parents features and factors “confidence” and “hesitancy”.

	VCI Factor 1: Confidence				VCI factor 2: Hesitancy
	Simple regression		Multiple regression		Simple regression		Multiple regression
	Est.	p	Est.	p	Est.	p	Est.	p
Gender
Female	–	–	–	–	–	–	–	–
Male	− 0.3352	.0154	− 0.2067	.0949	0.2753	.2400	–	–
Age
<30	–	–	–	–	–	–	–	–
30–34	0.1770	.4590	–	–	0.4047	.3155	–	–
35–39	− 0.1056	.6500	–	–	0.6502	.0974	–	–
40–44	− 0.0531	.8170	–	–	0.5740	.1369	–	–
45–49	0.1821	.4590	–	–	0.3494	.3990	–	–
>49	− 0.1887	.5130	–	–	0.8679	.0741	–	–
Education
Lower school	–	–	–	–	–	–	–	–
Higher school	0.1929	.201	0.1648	.2160	− 0.2552	.3089	− 0.3091	.2045
Bachelor degree or higher	0.2876	.070	0.2316	.1106	− 0.9996	.0002	− 0.8057	.0026
Occupation
Non-Healthcare worker	–	–	–	–	–	–	–	–
Healthcare worker	0.4553	.0513	0.0880	.6899	− 1.1964	.0022	− 0.5970	.1364
Number of children
1	–	–	–	–	–	–	–	–
2	0.2063	.0733	–	–	− 0.2679	.1680	–	–
>2	− 0.1900	.3063	–	–	− 0.1802	.1680	–	–
Previous vaccine status
No	–	–	–	–	–	–	–	–
Partial	− 0.3554	.4350	− 0.2193	.6259	1.3580	.0985	–	–
All	2.0523	<.0001	1.9710	<.0001	− 1.3757	.0713	–	–
Sources
Family	0.2069	.1350	–	–	− 0.2829	.2254	–	–
Acquaintance and friends	− 0.3220	.0732	–	–	0.3418	.2562	–	–
TV network	− 0.0057	.9720	–	–	0.5487	.0485	–	–
Internet	− 0.7242	<.0001	− 0.4038	.0005	1.3250	<.0001	1.1288	<.0001
Social Networks	− 1.1250	<.0001	− 0.5384	.0112	1.6481	<.0001	1.1619	.0028
Daily newspaper	− 0.0230	.9250	–	–	0.1815	0.6593	–	–
Magazines	0.2775	.2740	–	–	0.2621	0.5398	–	–
General practitioner	0.4674	.0027	0.2039	.1440	− 0.4488	0.0880	− 0.3433	0.1781
Health institutions	0.2315	.1270	–	–	− 0.5239	0.0400	− 0.4683	0.0611

Table 4. Association between VCI and parents’ characteristics.

	VCI Median (IQR)	Test
Gender		p = .006
Female	2.73 (1.50; 7.50)
Male	2.16 (1.28; 4.29)
Age
		p = .275
<30	3.33 (1.65; 9.33)
30–34	2.50 (1.56; 10.00)
35–39	2.50 (1.40; 7.00)
40–44	2.50 (1.43; 6.00)
45–49	2.73 (1.50; 7.00)
>49	2.04 (1.20; 4.29)
Education
		p < .001 * The 3rd category has an higher VCI than others for p < .001
Lower school	2.00 (1.21; 5.00))
Higher school	2.43 (1.36; 6.00)
Bachelor degree or higher	3.88 (1.88; 10.00)
Occupation
		p < .001
Non-Healthcare worker	2.50 (1.43; 7.00)
Healthcare worker	5.80 (2.52; 10.00)
Number of children
		p = .373
1	2.50 (1.50; 7.00)
2	2.73 (1.50; 7.50)
>2	2.24 (1.25; 7.00)
Vaccine status
		p < .001 * No difference between the 1st and 2nd category were reported, while the 3rd category was significantly higher than the others (p < .001)
No	1.88 (0.89; 3.40)
Partial	1.18 (0.79; 2.05)
All	2.73 (1.58; 7.50)
Source
Family		p = .430
No	2.50 (1.43; 7.25)
Yes	2.75 (1.67; 6.88)
Acquaintance and friends		p = .214
No	2.68 (1.50; 7.50)
Yes	2.08 (1.40; 4.29)
TV network		p = .002
No	2.73 (1.50; 7.50)
Yes	1.87 (1.27; 4.29)
Internet		p < .001
No	3.00 (1.58; 9.33)
Yes	1.87 (1.15; 4.29)
Social Networks		p < .001
No	2.73 (1.50; 7.50)
Yes	1.67 (1.04; 3.13)
Daily newspaper		p = .484
No	2.50 (1.47; 7.50)
Yes	2.15 (1.56; 4.29)
Magazines		p = .537
No	2.50 (1.46; 7.50)
Yes	2.15 (1.63; 4.29)
General practitioner		p = .015
No	2.00 (1.20; 5.75)
Yes	2.73 (1.50; 7.25)
Health institutions		p = .043
No	2.50 (1.43; 7.00)
Yes	3.33 (1.76; 7.50)

Table 5. Univariate logistic regression and multivariate logistic regression results between the intention to vaccinate (outcome, 1 = “willing to vaccinate”) and vaccine confidence index (VCI) and social media networks, internet and health institutions as main sources of information.

Variables	Reference	Participants	Univariate Logistic Regression OR (95% CI)	Multivariate Logistic Regression aOR (95% CI)
VCI	–	n = 743	1.81 (1.47–2.34)	1.64 (1.35–2.09)
Social Network	No	No = 700 Yes = 43	0.17 (0.09–0.33)	0.25 (0.12–0.54)
Internet	No	No = 563 Yes = 180	0.28 (0.17–0.45)	0.42 (0.25–0.70)
Heath Institution	No	No = 630 Yes = 113	2.34 (1.07–6.14)	2.84 (1.19–8.07)