A Systematic Review of Measures of Healthcare Workers' Vaccine Confidence

"...emphasizes the critical need for more culturally adapted and standardized tools for assessing vaccine hesitancy among HCWs."

Healthcare workers (HCWs)' perceptions toward vaccines influence patient and community vaccine decision making. Their vaccine confidence influences their likelihood to recommend vaccines, which can impact vaccine uptake among patients. Researchers have argued that, in an era of rising vaccine hesitancy, understanding HCW vaccine confidence is critical. This systematic review examines instruments that have been validated to measure HCW vaccine confidence. Its goal is to inform more targeted interventions and policies aimed at enhancing vaccine confidence among HCWs.

The researchers conducted a search in 5 databases in June 2023 and descriptively synthesised the data. Twelve articles describing 10 different tools were included. Table 1 in the paper summarises the aims, tools assessed, vaccines, dimensions of confidence measured by the tools, and results of the included articles. The majority of the articles (10/12) were published since 2013, and all expect one study were conducted in high-income countries.

Nine of the studies developed and validated novel tools. One study was based on the Vaccine Attitudes Examination (VAX) tool, which has been previously used for patient vaccine hesitancy, and 2 studies validated variations of the Health Professionals Vaccine Confidence and Behavior (Pro-VC-Be) tool. The tools examined different dimensions but covered many related topics. Nine of the 12 included studies assessed self-assessment of knowledge/skills of vaccination. Eight feature items relating to recommendation behaviour, safety of vaccines, and usefulness of vaccines. Seven tools gathered HCW perceptions on risk of vaccines, 6 assessed self-vaccination practices, 5 included influence of peer behaviour, and 4 gathered information on HCWs' sense of moral responsibility.

As reported here, the results from the studies mostly presented valid and reliable tools, but not all of the results focused on the validation process. There was also variability in the type of validations conducted. The Pro-VC-Be tool was the most well-validated one identified; it was validated 3 times in its long form and short-form, and international adaption tested it in 7 countries and 4 languages. The researchers indicate that the Pro-VC-Be tool is the most useful for future research and can be used as a standard for criterion validation because it underwent such a robust validation process.

Thus, results of the review show that, while there have been efforts to develop and validate tools, there were some key gaps in the literature and limitations with the existing studies. This, despite the fact that HCWs were identified as a core vaccine-hesitant group during the COVID-19 pandemic. The researchers recommend refocusing research efforts to place a stronger emphasis on how validation informs tool development and application to other studies. Furthermore, the review highlighted the limited geographical and income-level scope of existing research. Researchers have explained that the validation of a tool in one region does not mean that it is reliable and valid in another time, culture, and context. Thus, validation efforts should extend to other geographic regions in order to account for the unique challenges and dynamics of vaccine confidence in low- and middle-income settings.

In conclusion: "Addressing discrepancies in the existing research settings can significantly contribute to the understanding of HCWs vaccine hesitancy and inform targeted interventions and policies in a variety of settings."