A Multilingual Digital Microlearning Intervention for Oral Health in Refugee Shelters: Randomized Controlled Trial

Refugees frequently face language and access barriers to preventive oral health information. Brief multilingual digital interventions may help reduce such barriers in shelter settings.

This randomized controlled trial evaluated whether a multilingual digital microlearning video improved plaque control and selected self-reported oral health-related behaviors among adults living in refugee shelters.

A 2-arm, parallel-group randomized controlled trial was conducted among 86 adults living in 2 municipal refugee shelters in Germany. Participants were randomized (1:1) to receive either a multilingual 4-minute oral hygiene microlearning video or delayed access (control group). Plaque index and gingival index were assessed clinically at baseline and at 2-month follow-up. Secondary outcomes included questionnaire-based measures of oral health literacy-related cognitions and self-reported oral health behaviors. Between-group differences in change scores were analyzed using 2-sided tests; exploratory multivariable regression analyses were conducted to assess potential effect modifiers.

Follow-up was completed by 83 (97%) of 86 participants. Plaque index decreased more in the intervention group than in the control group (mean change -0.21, SD 0.27 vs mean change -0.04, SD 0.17; P=.002). Gingival index decreased in both groups, but the between-group difference was not significant. Among questionnaire-based outcomes, toothbrushing frequency increased substantially, whereas the remaining oral health literacy-related items showed small numerical changes that did not reach statistical significance or remained stable. Approximately three-quarters of participants in the intervention group (32/42, 76%) reported reviewing the video at least once.

Brief multilingual digital microlearning improved plaque control and self-reported toothbrushing frequency in refugee shelters. Effects on broader oral health literacy-related outcomes were limited and should be interpreted cautiously. Larger, prospectively powered trials with longer follow-up periods and blinded outcome assessment are warranted.