Table 3.

Multivariate logistic regression analyses indicating associations between independent variables and the different outcomes.

Variable	OR	SE	95% CI	p value
Model 1. Having heard about HPV infection and having the knowledge that infection can be transmitted through sexual intercourse
Log likelihood =− 534.32, χ2 = 49.95 (7 df), p<0.0001
Aware about the availability of the HPV vaccine in Italy	2.23	0.43	1.52–3.27	<0.001
Physicians as sources of information about the HPV vaccine	2.14	0.44	1.42–3.21	<0.001
Age at first complete sexual intercourse
No complete sexual intercourse	1*
<18 years	1.5	0.26	1.07–2.11	0.019
≥18 years	1.8	0.45	1.09–2.96	0.02
Health checkup in the last year	1.33	0.2	1.01–1.78	0.05
Number of partners in the last year
0	1*
≥2	1.26	0.24	0.86–1.84	0.227
Socio-economic status
Low	1*
High	0.84	0.14	0.61–1.16	0.301
Model 2. Positive attitude toward willingness to receive the HPV vaccine
Log likelihood = −429.47, χ2 = 222.76 (10 df), p<0.0001
Agree that the HPV vaccine is important for the protection against oral, penile, and anal cancers	1.31	0.04	1.22–1.4	<0.001
Agree that males should receive the HPV vaccine	3.28	0.55	2.35–4.58	<0.001
Age	0.9	0.03	0.85–0.96	0.002
Age at first complete sexual intercourse
No complete sexual intercourse	1*
≥18 years	3.89	1.83	1.54–9.8	0.004
<18 years	1.73	0.67	0.8–3.7	0.156
Knowledge that both males and females can acquire the HPV infection	1.49	0.28	1.03–2.15	0.032
Preoccupation to acquire the HPV infection	1.06	0.04	0.99–1.15	0.097
Socio-economic status
Low	1*
High	1.29	0.25	0.88–1.87	0.183
Number of partners in the last year
0	1*
1	0.67	0.25	0.32–1.38	0.282
≥2	0.65	0.25	0.31–1.39	0.273
Model 3. Perceived need of more information about the HPV vaccine
Log likelihood =− 311.26, χ2 = 52.57 (10 df), p<0.0001
Agree that the HPV vaccine is important for the protection against oral, penile, and anal cancers	1.14	0.37	1.05–1.23	0.001
Age at first complete sexual intercourse
No complete sexual intercourse	1*
≥18 years	3.19	1.55	1.23–8.29	0.017
Physicians as sources of information about the HPV vaccine	2.25	0.79	1.13–4.49	0.21
Number of partners in the last year
0	1*
1	1.74	0.44	1.06–2.87	0.028
≥2	1.51	0.4	0.89–2.55	0.125
Agree that males should receive the HPV vaccine	1.49	0.32	0.97–2.28	0.067
Preoccupation to acquire the HPV infection	1.09	0.05	0.99–1.19	0.073
Socio-economic status
Low	1*
Intermediate	0.79	0.16	0.53–1.19	0.265
Aware about the availability of the HPV vaccine in Italy	1.31	0.37	0.75–2.31	0.342

^*Reference category