Economic Evaluations of School Sealant Programs and the Consent Conundrum.

Past and current economic evaluations of school-based sealant programs (SSPs) have leveraged the existing clinical trial data on sealant effectiveness to support SSP implementation (Gooch et al. 2009; Griffin et al. 2016; Griffin et al. 2017). These economic evaluations have been important to demonstrate the potential value of SSPs and to attract scarce funding dollars for implementation (Griffin et al. 2014; Griffin et al. 2018). However, given the broad recommendations to implement SSPs (Gooch et al. 2009; Griffin et al. 2016; Griffin et al. 2017), there is now a need to evaluate how variation in SSP design and implementation affects oral health outcomes and costs. Such an analysis may help address the stall in SSP implementation efforts as of 2015 (Pew Charitable Trusts 2015). This requires direct data on SSP effectiveness rather than sealant efficacy. The consent process in SSPs may be a major component of SSP effectiveness that has yet to be examined. Passive and active consent notifies children’s parents or guardians of an ongoing study and requires a parent’s or guardian’s signature to decline (passive consent) or accept (active consent) program participation. Active consent is typically needed for any program providing care; hence, SSPs typically require active consent procedures. Students with active consent to participate in research may systematically differ from those without consent. Additionally, active consent procedures for research may exclude individuals who would otherwise participate in clinical care. The study sample then is not representative of the entire school population or even all those who would participate in clinical care within the school population. The resulting bias in the study sample is called self-selection bias, and it threatens internal and external validity. Assessing the impact of SSPs on school populations when the school population is not well represented in the sample is difficult. An additional complication is the variation across institutional review boards (IRBs) in consent requirements. A recent study examined variation in consent strategies required by 24 local IRBs (Higgerson et al. 2014). Although submitted IRB applications were the same across the 24 IRBs, researchers found IRBs inconsistent in interpreting federal regulations regarding passive consent and parental acceptance of passive consent strategies. Additionally, standards for active consent procedures may vary across IRBs, which may depend on the local setting (Silverman et al. 2001). However, the resulting variation in consent procedures may lead to differences in the magnitude of self-selection bias across SSPs collecting data for research. Hence, it becomes important that economic evaluations report clearly on potential self-selection bias in the underlying data and provide information about the consent procedures used to procure the data. Otherwise, decision making could be ill-informed. At best, economic evaluations with unreported sources of bias are uninformative and not useful for decision making. At worst, biased economic evaluations may lead to suboptimal allocation of scarce resources. In the following discussion, we highlight challenges associated with informed consent in economic evaluations of SSPs and whether they have been addressed in recent economic evaluations, and we provide recommendations for future work. Assess Program Impact Based on All Students, Not Just Those with Informed Consent A key tenet of economic evaluations is to conduct intention-to-treat analysis. Because schools typically do not allow for differential targeting of students within their student populations, school-based programs are necessarily conducted schoolwide, and treatment is offered to every student. Hence, the unit for treatment assignment is the school. As a result, based on the intention-to-treat approach for economic evaluations suggested by International Society for Pharmacoeconomics and Outcome Research (ISPOR) (Husereau et al. 2013), the incremental impact on cost and health outcomes for all students within schools implementing school-based programs should be considered. Not using intention-to-treat analysis can significantly bias estimates of the program impact. Suppose that only 20% of children participate in any SSP. Although children participating in the program may experience an 80% reduction in caries relative to what would have occurred without an SSP, the overall reduction in caries within the school is far below 80%. Furthermore, the 80% reduction in caries due to the SSP may not be generalizable to nonparticipants or to the overall school population. Economic evaluations not accounting for nonparticipation or assuming full participation may therefore be significantly biased in their assessment of SSPs.