Background: Poor oral health is negatively associated with absenteeism, being attributed to millions of lost school days per year. The role of school-based dental programs that address oral health inequities on student attendance has not yet been explored. Methods: CariedAway was a longitudinal, cluster-randomized, non-inferiority trial of preventive medicines for dental caries used in a school-based program. To explore the potential impact of caries prevention on attendance, we extracted data on average school absenteeism and the proportion of chronically absent students from publicly-available datasets maintained by the New York City Department of Education for years before, during, and after program onset. Data were obtained for all CariedAway schools as well as a group of untreated comparator schools. Total absences and the proportion of chronically absent students were modeled using multilevel mixed effects linear and two-limit tobit regression, respectively. Multiple model specifications were considered, including exposures to time-varying treatments across multiple years. Models also included a group of untreated comparator schools. Results: In years in which treatment was provided through a school-based comprehensive caries prevention program, schools recorded approximately 944 fewer absences than in non- treatment years (95% CI = -1739, -149). Averaged across all study years, schools receiving either treatment had 1500 fewer absences than comparator schools, but this was not statistically significant. In contrast, chronic absenteeism was found to significantly decrease in later years of the program (B = -.037, 95% CI = -.062, -.011). Removing data for years affected by COVID-19 eliminated the significant reduction in total absences during treatment years, yet still showed a marginally significant interaction for chronic absenteeism. Discussion: Though originally designed to mitigate access barriers to critical oral healthcare, early integration of school-based dental programs may positively impact school attendance. However, concerns over the reliability of attendance records due to the closing of school facilities resulting from COVID-19 may mask the true effect.

The authors have declared no competing interest.

NCT03442309

Research reported in this publication was funded through a Patient-Centered Outcomes Research Institute (PCORI) Award (PCS-1609-36824). The content is solely the responsibility of the authors and does not necessarily reflect the official views of the funding organization, New York University, or the NYU College of Dentistry.

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The study received ethical approval from the New York University School of Medicine Institutional Review Board (#i7- 00578) and is registered at www.clinicaltrials.gov (#NCT03442309, 22/09/2018)

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