Table 4.

Likert scales scores for psychometric variables and knowledge stratified for HCWs actively ‘protected’ status against influenza (mean value ± standard deviation and statistical significance of differences at non parametric Wilcoxon' rank-sum test).

	Against influenza
Interval scale from −1 to +1	Actively protected	Not actively protected
Personal responsibility in HCWs' vaccination	0.63 ± 0.37	0.35 ± 0.46	***
Beliefs on preventive usefulness of vaccines	0.67 ± 0.67	0.42 ± 0.42	***
Beliefs on vaccines-related risks	−0.51 ± 0.40	−0.13 ± 0.43	***
Perceived susceptibility to infectious diseases	0.74 ± 0.33	0.67 ± 0.45	n.s.
Knowledge on recommended vaccines for HCWs	0.00 ± 0.30	0.04 ± 0.37	n.s.

Actively protected = HCWs vaccinated against influenza

Not actively protected = HCWs not-vaccinated against influenza

^*= p < 0.05;

^**= p < 0.01;

^***= p < 0.001.