Psychometric properties of the Fluoride Hesitancy Identification Tool (FHIT)

by Adam C. Carle, Isabella Pallotto, Todd C. Edwards, Richard Carpiano, Darragh C. Kerr, Donald L. Chi

Introduction

Some caregivers are hesitant about topical fluoride for their children despite evidence that fluoride prevents caries and is safe. Recent work described a five domain model of caregivers’ topical fluoride hesitancy. We developed the Fluoride Hesitancy Identification Tool (FHIT) item pool based on the model. This study sought to evaluate the FHIT’s psychometric properties in an effort to generate a short, simple to score, reliable, and valid tool that measures caregivers’ topical fluoride hesitancy.

Methods

In 2021 and 2022, we conducted an observational, cross-sectional study of caregivers, collecting data from two independent caregiver samples (n₁ = 523; n₂ = 612). The FHIT item pool included 33 items. We used confirmatory factor analyses (CFA) to examine whether the FHIT items measured five separate domains as hypothesized and to reduce the number of items. We then fit item response theory (IRT) models and computed Cronbach’s alpha for each domain. Last, we examined the construct validity of the FHIT and evaluated scoring approaches.

Results

After dropping 8 items, CFA supported a five factor model of topical fluoride hesitancy, with no cross-loadings (RMSEA = 0.079; SRMR = 0.057; CFI = 0.98; TLI = 0.98). We further reduced the items to four per domain (20 items total). Marginal alphas showed that the item sets provided reliability of ≥0.90 at hesitancy levels at and above average. The domains correlated more strongly with each other and topical fluoride refusal than with other questions on the survey.

Discussion

Our results support the FHIT’s ability to reliably and validly measure five domains of topical fluoride hesitancy using the average score of the four items in each domain.