[Design and validation of a questionnaire for assessing Public Health residents' opinions and knowledge regarding the new mandatory vaccination law in Italy (DL 73/2017)]

Vaccines are an important tool to prevent communicable diseases. Despite their importance, vaccines seem to be victims of their own success and declining levels of vaccination uptake have been recorded in Europe and Italy. For this reason, Italy introduced a new mandatory vaccination law on July 31, 2017. We aimed to validate a questionnaire to assess the opinions and knowledge of Public Health residents about this issue.A team of public health residents developed a questionnaire and validated it by administering it to a panel of 10 Public Health residents, members of the Vaccines and Vaccine Hesitancy Working Group of the Public Health residents Assembly of the Italian Society of Hygiene and Preventive Medicine. Cronbach's Alpha and Cohen's Kappa tests were used to analyse results.The final version of the questionnaire consisted in 23 items. The validation process showed a high level of internal consistency (alpha=0,82). The tests showed a relevant level of agreement (k= 0,75 ± 0,07). Finally, the feasibility test pointed out that 80% of respondents declared the questions were clear and easy to understand.The designed questionnaire is a valid and useful tool.