Development and validation of the Oxford Benchmark Scale for Rating Vaccine Technologies (OBSRVT), a scale for assessing public attitudes to next-generation vaccine delivery technologies.

Abstract

Next-generation vaccine delivery technologies may provide significant gains from both a technical and behavioral standpoint, but no scale has yet been developed to assess public attitudes to novel vaccine delivery technologies. We therefore performed a cross-sectional validation study that included 1,001 demographically representative participants from the UK and US to develop and validate a novel scale, the Oxford Benchmark Scale for Rating Vaccine Technologies (OBSRVT). A sample of 500 UK participants was used to perform exploratory factor analysis with categorical variables (using a polychoric correlation matrix) followed by promax oblique factor rotation to develop the initial model. This yielded a 15-item 4-domain scale with domains including acceptance (6 items), effectiveness (4 items), comfort (3 items), and convenience (2 items). This model was tested for robustness on a 501-participant demographically representative sample from the US. A confirmatory factor analysis with a Satorra-Bentler scaled test statistic was performed, which demonstrated adequate goodness of fit statistics including the root mean squared error of approximation (0.057), standardized root mean squared residual (0.053), and comparative fit index (0.938). Reliability as internal consistency was excellent (alpha = 0.92). Convergent validity with the Oxford Needle Experience Scale was supported by an adequate correlation (r = 0.31, p < .0001), while discriminant validity was supported by a lack of correlation with an unrelated question (r = -0.03, p < .0001). These findings suggest that the OBSRVT scale represents a feasible, valid, and reliable scale that could be used to gauge the acceptability of existing and future vaccine delivery technologies, and further investigation and testing should be considered.