We evaluated the feasibility and acceptability of a theory-based self-care for oral health e-learning intervention and verified the potential effect in Japanese overseas workers with pre- and post-follow-up studies with comparison with a control group. The study results showed that the theory-based e-learning program was a feasible and acceptable oral health behaviour intervention for expatriates in the target population. They also showed the potential effects of the intervention on oral health behaviours and oral health knowledge.
Feasibility
The high completion rate of the e-learning package and the positive evaluation of the e-learning learning materials suggest that although most research on oral care education has been conducted with children or dental students [21, 22], education for adults is also well tolerated.
One of the challenges we experienced was the small number of expatriates between the ages of 20 and 40 years who went abroad for long-term periods due to the spread of COVID-19. Since our program was focused on dental caries prevention at young and early middle stages, we excluded the middle-aged and older age groups. Therefore, in a full-scale RCT, recruitment during the recruitment period should be considered to increase the number of overseas workers who agree to participate in the study. For those who participated in the intervention, the rate of loss to follow-up was high, although few discontinued the intervention. As the study involved overseas workers, the posttest data collection was very time consuming. A longer posttest collection period from the outset, taking into account the time difference and internet availability when the questions were asked, would have reduced the drop-out rate.
According to the evaluations of the content, the illustrations and cartoons were highly appreciated. In the e-learning program in this study, the participants’ attention may have been attracted by the design and colours that were used to make the elements of the IMB model attractive to learn.
One of the negative comments was that it took too much time to learn the material. It takes approximately 40-45 minutes to watch the material. Considering that most participants spent 10-30 minutes watching the material, the content needs to be reduced slightly.
Clinical efficacy
Although this pilot study had insufficient sample size to detect differences in oral health behaviours due to the intervention, it does suggest the possibility that the intervention may increase oral health knowledge. These results are not surprising, as IMB-based oral health messages promote changes in self-reported knowledge [23]. There were also significant changes in motivation and behavioral skills for e-learning users in the pre- and postintervention comparisons. However, there were no significant changes in these outcomes compared to the leaflet users. This is probably due to the low power of the study, so future research should be conducted with a larger sample size to test the hypothesis.
Four measures of fluoride use behaviour were compared to assess whether oral health behaviours changed with improvement in these three components of the IMB model. The results suggest that the intervention had a potentially positive impact on oral health behaviours, and these behaviours need to continue to be tested with larger samples.
Recent studies have shown that the use of high concentrations of fluoride is highly effective in preventing dental caries and periodontal disease [24]. In 2020, the WHO published a Model List of Essential Medicine describing the most effective, safe and cost-effective medicines for priority conditions. In this list, fluoride is shown as the minimum essential medicine for dental products, and a fluoride concentration of 1000 to 1500 ppm is recommended [25]. In the e-learning program we developed, the use of high-concentration fluoride was explained using the IMB model, and most participants in the intervention group who received e-learning improved their knowledge. However, the effects of intervention materials need to be assessed with a sufficiently large sample size, as the interaction effects are not clear.
Limitations
A potential limitation is that the results were based on self-reported data, and the use of more objective measures of data would help to improve the accuracy with which oral health behaviours are measured. In addition, because of the study setting, leaflets were also distributed to the e-learning group. It is possible that the oral health care effects of the leaflets may have influenced the results, but our difference-in-difference study design was intended to account for the shared effect of these leaflets in both groups, so this is unlikely to be a significant limitation. Another potential limitation is that the sample was recruited only from volunteer organizations in Japan; in addition, the study participants were mostly female, which may have affected the representativeness of the target population.