Vaccine exemption requirements and parental vaccine attitudes: an online experiment.

Increases in vaccine hesitancy and vaccine-preventable disease outbreaks have focused attention on state laws governing school-entry vaccine mandates and the allowable exemptions (medical and nonmedical) from those mandates. There is substantial variation in the type of exemptions available in each state, and states with more rigorous or burdensome exemption requirements generally have lower exemption rates. States have little evidence, however, about how vaccine-hesitant parents respond to different requirements. Despite recent efforts to formulate "model legislation" templates for states to follow, policy evidence about optimal exemption regimes is limited to observational studies in states that have changed exemption laws. We conducted two online experiments to explore how parental attitudes and intentions responded to different school-entry vaccine mandate exemption requirements. We randomly assigned online participants to one of four hypothetical vaccine exemption application scenarios: parental signature only, a checklist of vaccines for which an exemption is requested, a lengthy (10-30+ min) video-based vaccine education module, and a requirement to write a statement justifying the exemption. Among parents with high vaccine hesitancy, a required vaccine education module led to significant decreases in vaccine hesitancy, while checklist and justification requirements increased vaccine hesitancy slightly. Among parents with low vaccine hesitancy, we observed a potential backfire effect when parents were required to write a justification statement. Our findings warrant replication in a larger, fully-powered trial to accelerate knowledge about how parents across the vaccine hesitancy spectrum respond to exemption regimes.

Comparison of Online Survey Recruitment Platforms for Hard-to-Reach Pregnant Smoking Populations: Feasibility Study.

BACKGROUND: Recruiting hard-to-reach populations for health research is challenging. Web-based platforms offer one way to recruit specific samples for research purposes, but little is known about the feasibility of online recruitment and the representativeness and comparability of samples recruited through different Web-based platforms. OBJECTIVE: The objectives of this study were to determine the feasibility of recruiting a hard-to-reach population (pregnant smokers) using 4 different Web-based platforms and to compare participants recruited through each platform. METHODS: A screener and survey were distributed online through Qualtrics Panel, Soapbox Sample, Reddit, and Amazon Mechanical Turk (mTurk). Descriptive statistics were used to summarize results of each recruitment platform, including eligibility yield, quality yield, income, race, age, and gestational age. RESULTS: Of the 3847 participants screened for eligibility across all 4 Web-based platforms, 535 were eligible and 308 completed the survey. Amazon mTurk yielded the fewest completed responses (n=9), 100% (9/9) of which passed several quality metrics verifying pregnancy and smoking status. Qualtrics Panel yielded 14 completed responses, 86% (12/14) of which passed the quality screening. Soapbox Sample produced 107 completed surveys, 67% (72/107) of which were found to be quality responses. Advertising through Reddit produced the highest completion rate (n=178), but only 29.2% (52/178) of those surveys passed the quality metrics. We found significant differences in eligibility yield, quality yield, age, number of previous pregnancies, age of smoking initiation, current smokers, race, education, and income (P<.001). CONCLUSIONS: Although each platform successfully recruited pregnant smokers, results varied in quality, cost, and percentage of complete responses. Moving forward, investigators should pay careful attention to the percentage yield and cost of online recruitment platforms to maximize internal and external validity.