Vaccine hesitancy as indecision: Creation and evaluation of the Unidimensional Vaccine Hesitancy Scale.

Several authors have argued that vaccine hesitancy should be conceptualized as indecision in the vaccination decision-making process, but no established measure with support for its psychometric properties and validity has been created from this operational definition. To resolve this tension, this article undergoes a four-study scale development process to create the 4-item Unidimensional Vaccine Hesitancy Scale (UVHS). We conduct four survey studies utilizing a total sample size of 884. In Studies 1 (n = 297) and 2 (n = 298), we provide psychometric support for the measure via exploratory and confirmatory factor analysis. In Studies 3 (n = 193) and 4 (n = 106), we support the concurrent and discriminant validity of the measure by assessing its relations with relevant constructs, such as vaccination readiness and acceptance, and we also provide initial indicators of the scale's possible predictive qualities by testing its time-separated effects with vaccination willingness, receipt and word-of-mouth. We leverage these results to provide a number of theoretical insights and suggestions for future practice. Of note, we highlight that different conceptualizations and operationalizations for the same construct can produce notably differing empirical findings, and vaccine hesitancy is no different. Our cumulative efforts indicate that the UVHS is an appropriate measure to assess vaccine hesitancy as indecision.

Howard MC 《-》

Vaccine hesitancy relates to vaccine hesitancy? Discovering nonlinear relations between differing operationalizations of vaccine hesitancy.

Vaccine hesitancy is often conceptualized as negative perceptions regarding vaccines, but recent authors have increasingly argued that the construct should instead be conceptualized as indecision in the vaccination decision-making process. This has caused authors to reevaluate the placement of vaccine hesitancy in associated models and frameworks, and it has caused uncertainty regarding how these two conceptualizations relate to each other. In the current article, we argue that the relation between these two conceptualizations of vaccine hesitancy is best understood via nonlinear effects. Specifically, we argue that this relation takes an inverted U-shape. We utilized a cross-sectional survey design. We recruited 273 participants from Prolific who completed two measures of vaccine hesitancy: an eight-dimension measure reflecting negative perceptions of vaccines and a unidimensional measure reflecting indecision in the vaccine decision-making process. We performed eight quadratic regression analyses (one for each dimension) to assess our proposed nonlinear relation. The quadratic term was significant in all eight regression analyses (all p < .01), supporting our proposed inverted U-shape relation. Our results provide reasoning for future authors to test whether vaccine hesitancy as negative perceptions impacts vaccination via vaccine hesitancy as indecision, and researchers must now recognize their nonlinear relation in any developed models and frameworks.

Howard MC 《-》

Oxford Vaccine Hesitancy Scale (OVHS): a UK-based and US-based online mixed-methods psychometric development and validation study of an instrument to assess vaccine hesitancy.

To describe the development, validation and reliability of the Oxford Vaccine Hesitancy Scale (OVHS), a new instrument to assess vaccine hesitancy in the general population. Cross-sectional validation study. Internet-based study with participants in the UK and USA. Demographically representative (stratified by age, sex and race) samples from the UK and USA recruited through the Prolific Academic platform. To demonstrate OVHS development, exploratory factor analysis with categorical variables and a polychoric correlation matrix followed by promax oblique rotation on the UK sample was performed. Confirmatory factor analysis with a Satorra-Bentler scaled test statistic evaluating goodness of fit statistics including the root mean squared error of approximation (RMSEA), standardised root mean squared residual (SRMR) and comparative fit index (CFI) was performed on the US sample. Reliability as internal consistency was assessed using McDonald's omega. Evidence in support of the predictive, convergent and discriminant validity of the scale was assessed using logistic regression ORs of association (OR) or Pearson correlation coefficients. Data for factor analysis were obtained from 1004 respondents, 504 in the UK and 500 in the USA. A scree plot, minimum average partial correlation analysis and parallel analysis suggested a three-factor 13-item scale with domains of vaccine beliefs (seven items), pain (three items) and personal deliberation (three items). Responses were recorded on a Likert scale ranging from disagree completely to agree completely, with higher score reflecting greater hesitancy. Potential total scores ranged from 13 to 65. Goodness of fit was excellent, with RMSEA=0.044, SRMR=0.041 and CFI=0.977. Predictive validity for COVID-19 vaccination status was excellent, with logistic regression ORs of association (95% CI) of 0.07 (0.04, 0.13), p<0.0001 for the UK sample for each SD increase in OVHS score, suggesting a 93% decrease in the odds of being vaccinated against COVID-19 for each SD increase in OVHS score. Convergent validity between the OVHS score and the 5C short version scale demonstrated a correlation coefficient of 0.32 (p<0.0001). Discriminant validity with an unrelated desire to perform outdoor activities demonstrated an OR (95% CI) of 1.06 (0.88, 1.29), p=0.523 for the UK sample for each SD increase in OVHS score. McDonald's omega was 0.86 and 0.87 in the UK and US samples, respectively. The OVHS is a feasible, valid and reliable scale for assessing vaccine hesitancy; further testing is warranted.

Kantor J ，Carlisle RC ，Morrison M ，Pollard AJ ，Vanderslott S ... -  《BMJ Open》

Parental hesitancy toward children vaccination: a multi-country psychometric and predictive study.

Understanding vaccine hesitancy, as a critical concern for public health, cannot occur without the use of validated measures applicable and relevant to the samples they are assessing. The current study aimed to validate the Vaccine Hesitancy Scale (VHS) and to investigate the predictors of children's vaccine hesitancy among parents from Australia, China, Iran, and Turkey. To ensure the high quality of the present observational study the STROBE checklist was utilized. A cross-sectional study. In total, 6,073 parent participants completed the web-based survey between 8 August 2021 and 1 October 2021. The content and construct validity of the Vaccine Hesitancy Scale was assessed. Cronbach's alpha and McDonald's omega were used to assess the scale's internal consistency, composite reliability (C.R.) and maximal reliability (MaxR) were used to assess the construct reliability. Multiple linear regression was used to predict parental vaccine hesitancy from gender, social media activity, and perceived financial well-being. The results found that the VHS had a two-factor structure (i.e., lack of confidence and risk) and a total of 9 items. The measure showed metric invariance across four very different countries/cultures, showed evidence of good reliability, and showed evidence of validity. As expected, analyses indicated that parental vaccine hesitancy was higher in people who identify as female, more affluent, and more active on social media. The present research marks one of the first studies to evaluate vaccine hesitancy in multiple countries that demonstrated VHS validity and reliability. Findings from this study have implications for future research examining vaccine hesitancy and vaccine-preventable diseases and community health nurses.

Sharif-Nia H ，She L ，Allen KA ，Marôco J ，Kaur H ，Arslan G ，Gorgulu O ，Osborne JW ，Rahmatpour P ，Khoshnavay Fomani F ... -  《-》

Development of a vaccine hesitancy scale for childhood immunization in China.

Vaccine hesitancy is a primary factor that influences vaccine uptake; however, no specific measurement tool to accurately assess vaccine hesitancy is available in China. This study aimed to develop a general vaccine hesitancy scale for childhood immunization. We adopted a three-phase process with nine steps to develop and finalize our scale. The scale framework and initial item pool were determined by a literature review. Expert consultation and cognitive interviews with parents were conducted to evaluate content validity. Questionnaire surveys involving parents of children aged <6 years were conducted to select items. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were employed to identify and validate the scale factor structure. The scale's reliability and validity were assessed using multiple indicators. Of the initial 38 items, 21 were retained after expert consultation and cognitive interviews. In survey 1, the number of scale items decreased to 16 following item analysis and EFA. In survey 2, four items were added and EFA identified four factors. In survey 3, CFA confirmed the four-factor structure and the reliability indicators were satisfactory for the total scale. The level of vaccine hesitancy assessed by our scale was positively associated with vaccination refusal behavior and the Vaccine Hesitancy Scale score. The final scale comprised four dimensions (confidence, complacency, convenience, and calculation) with 17 items. We developed a validated and reliable measurement to assess vaccine hesitancy among parents of children, which promises to be suitable for wide use in China.

Yao X ，Peng J ，Ma Y ，Fu M ，Fang Y ，Fang H ，Jiang M ... -  《-》