Learning Objectives for this Presentation:
By the end of the presentation participants will be able to understand the relation between vaccine hesitancy and school exemptions using a five item attitudinal measure developed by the Oregon Immunization Program.

Background:
General population surveys can be problematic for measuring uncommon items. For measuring vaccine hesitancy, a survey is likely to hit few of a rarer anti-vaccine or high-hesitancy population, yet is likely to contain many with lower levels of concern or awareness of anti-vaccine claims. This lower concern population is more likely to be amenable to traditional education or provider advice. Distinguishing a more easily reachable population of vaccine hesitant parents from those with a more firm anti-vaccine attitude is one need for designing effective interventions.

Objectives:
To present an attitudinal-based measure of vaccine hesitancy for use in population surveys that was derived from a population with known exemption statuses and vaccination attitudes.

Methods:
The Oregon Parental Exemption Survey was a multi-stage cluster survey of Oregon households with elementary students, with selection based on known exemption status. A battery of five attitudinal items were considered in different weightings and systems for producing a dichotomous vaccine hesitancy variable and a continuous scale. All results were examined for sensitivity and specificity against outcome measures including school exemptions.

Results:
The presented measure of vaccine hesitancy possesses a high degree of association against school exemptions in an Oregon population, (OR=57.4). The design of this measure allows for the segmentation of a survey population by levels of vaccine resistance. In addition adequate levels of specificity and sensitivity were obtained by this measure for use beyond exploratory analysis.

Conclusions:
The Oregon vaccine hesitancy scale was shown in this study to have strong predictive value, and to have utility in detecting vaccine-hesitancy levels among different survey groups.