Motivational interviewing at home: A community trial to improve oral health literacy and reduce morbidity in disadvantaged Chilean families.

Background: Limited evidence exists regarding the effects of home-based interventions on oral health outcomes in preschool-aged children or caregivers despite the success of such interventions in other child and pregnancy health outcomes. The aim of this community trial was to assess the impact after 12 months of a home-delivered motivational interviewing (MI) intervention on oral health outcomes in disadvantaged Chilean families.

Methods: This trial was conducted with a community single-blinded design, including preschoolers (aged 2-4 years) and their caregivers from 2 disadvantaged communities who received either the MI intervention or standard oral health interventions at kindergartens. The MI intervention comprised from 4 through 6 tailored home visits by MI-trained dental hygienists. Data on socioeconomic-demographic factors, caries (International Caries Detection and Assessment System [ICDAS]), oral hygiene, and caregivers' oral health literacy (OHL) (assessed with Oral Health Literacy Instrument and Rapid Estimate of Adult Literacy in Dentistry, 30 items) were collected at baseline and 12-month follow-up.

Results: Two hundred fifty-two dyads completed baseline measurements, and 212 completed the follow-up (control, n = 104; intervention, n = 108). Weak associations were found between clinical-sociodemographic factors and OHL at baseline (correlations, < 0.3) and follow-up. Analysis of covariance revealed a reduction in caries incidence for lesions with ICDAS scores above 0 (P = .03) but not for ICDAS scores above 2 (P = .47). No reduction in oral hygiene was observed (P = .74). Oral Health Literacy Instrument scores showed no improvement (P = .10), and Rapid Estimate of Adult Literacy in Dentistry, 30 items scores showed a marginal increase (P = .03).

Conclusions: Home-delivered MI intervention had a marginal impact on preschoolers' caries incidence and caregivers' OHL but no effect on preschoolers' oral hygiene, with the primary impact observed at the level of caries ICDAS scores above 0.

Practical implications: Home-delivered MI interventions by dental hygienists marginally reduce caries incidence in preschoolers from disadvantaged populations. This trial was registered at the Australian and New Zealand Clinical Trials Registry. The registration number is ACTRN12615000450516.