Letter to the Editor on the e-SEM Programme: Methodological Considerations and Critical Perspectives on a Theory-Driven Digital Oral Health Intervention by Acosta and Pisarnturakit

Dear Editor, I read with considerable interest the article by Acosta and Pisarnturakit titled “Empowered Smiles Through Education and Motivation (e-SEM): A Theory-Driven Digital Oral Health Behaviour Intervention,” recently published in the International Dental Journal.¹ The authors describe a methodological 3-phase framework for developing and validating a digital media-based oral health intervention for Filipino schoolchildren, grounded in the information, motivation, and behavioural skills (IMB) model. While the work represents a commendable effort to integrate theory-driven design with cultural adaptation and digital delivery, several methodological, conceptual, and translational issues merit further critical discussion.

Construct validity of the IMB model operationalisation

The IMB model provides a well-established theoretical scaffold; however, the mapping of digital media components to IMB constructs (Table 1 of the original article) raises questions of construct specificity. For instance, the authors classify “animated storytelling videos” as simultaneously serving informational, personal motivational, and social motivational functions. This overlap risks conflating theoretically distinct constructs and undermines the ability to identify which specific IMB component drives behaviour change in subsequent effectiveness trials. A clearer operational definition demarcating the boundaries between each construct alongside component-specific outcome measures aligned to the respective IMB domain would substantially strengthen the theoretical integrity of the intervention. Future iterations of e-SEM would benefit from confirmatory factor analysis or structural equation modelling to empirically verify that each component loads onto its intended IMB construct rather than relying on face-level content mapping alone.²

Content validity methodology: panel size and disciplinary breadth

The content validation relied on a panel of 5 experts, comprising 2 public health professionals and 3 education and research specialists. While this composition aligns with Lawshe’s original framework, the absence of representatives from human–computer interaction, user experience design, developmental psychology, and cultural anthropology is a meaningful limitation, particularly for a digital intervention designed for children aged 9 to 12 years. The usability and engagement dimensions of digital tools for children are governed by principles that extend well beyond oral health content expertise: age-appropriate cognitive load, interface affordances, narrative pacing, and visual literacy are specialised domains.³ The authors acknowledge this limitation briefly but do not discuss its potential impact on the validity ratings obtained. Notably, the animated storytelling component, arguably the most design-intensive element, received the lowest Content Validity Index (CVI) (0.83), which may be partially attributable to insufficient design expertise on the validation panel rather than inherent content shortcomings. This distinction is important for interpreting the findings accurately.

End-user sampling: representativeness and risk of social desirability bias

The acceptability and usability assessment was conducted with convenience samples of 20 parents and 20 children. While the authors frame these as purposive samples representative of the target population, no sociodemographic characterisation of these participants is provided; details such as parental education level, household digital literacy, device access, or children’s prior digital health exposure are absent. This is a notable gap, as these variables are well-established moderators of the acceptability of digital health interventions.⁴ Furthermore, the structured questionnaire format administered immediately following exposure to the materials is susceptible to social desirability bias and novelty effects, particularly among children. A post hoc reevaluation after a brief interval or the use of behavioural engagement metrics (eg, time-on-task, revisit rates, or eye-tracking data in user testing contexts) would provide more ecologically valid evidence of genuine engagement and usability.

The premature conflation of validation with feasibility

The authors conclude that the e-SEM programme demonstrates “feasibility as a theory-driven digital oral health intervention.” Content validity and acceptability ratings, regardless of how high, do not provide evidence of feasibility in the formal implementation science context. Feasibility encompasses implementation fidelity, resource requirements, provider capacity, technological infrastructure, and equity of access, none of which were assessed in the current study.⁵ In the Philippine school context, structural challenges such as inconsistent internet connectivity, variable device availability, and teacher digital competency represent significant potential barriers. The authors’ brief acknowledgement of offline solutions and low-data platforms is insufficient; a dedicated feasibility study with a structured assessment of these implementation determinants is warranted before the programme can be reasonably positioned as “ready for school-based implementation.”

Absence of child-reported outcome measures aligned to behavioural intention

The child questionnaire assesses “behavioural intention” as 1 of 4 domains, rated on a 3-point smile-based scale. While the scale is developmentally adapted, the single-domain measurement of intention conflates the attitudinal and volitional components of behaviour change that the IMB model explicitly separates as motivation and behavioural skills. The measurement instrument, therefore, does not map directly onto the theoretical framework underpinning the intervention, a misalignment that should be addressed in subsequent phases. Validated paediatric oral health literacy and self-efficacy instruments, such as the Child Oral Health Impact Profile or adapted versions of the Oral Health Literacy Assessment for children, could provide more robust and theoretically coherent outcome measures for future effectiveness trials.⁶

Inclusivity and accessibility: an underexplored dimension

The article briefly notes that the e-SEM programme is not suitable for children with hearing or visual impairments and suggests that future versions may incorporate audio narration or sign language support. This acknowledgement, while appropriate, underscores a broader concern: inclusive design principles were not integrated into the development phase of the intervention. Retrofitting accessibility features postdevelopment is less effective than embedding Universal Design for Learning principles from the outset.⁷ Given that the target population, Filipino schoolchildren, includes a meaningful proportion of children with varying abilities in resource-limited settings, the absence of a codesign process involving children with diverse needs represents a missed opportunity to enhance both equity and impact.

Conclusion

Acosta and Pisarnturakit¹ have made a timely contribution by introducing a culturally grounded, IMB-based digital oral health intervention framework for Filipino schoolchildren. The structured developmental methodology, high content validity indices for most components, and strong acceptability ratings are encouraging. Nonetheless, the issues raised above regarding construct operationalisation, panel composition, sampling adequacy, feasibility claims, measurement alignment, and inclusive design reflect substantive methodological considerations that should be addressed in subsequent studies. Refining these dimensions would considerably strengthen the evidence base for e-SEM and meaningfully advance the field of theory-driven paediatric digital oral health interventions.

Conflict of interest

None disclosed.