# Structural Validity and Measurement Invariance of the Scale of Oral Health Outcomes for 5‐Year‐Old Children

## TL;DR

This study evaluates the reliability of a child self-reported oral health quality-of-life scale for 5-year-olds across different cultural and clinical settings.

## Contribution

The study provides empirical validation of the SOHO-5 scale's unidimensionality and partial cross-cultural measurement invariance.

## Key findings

- The SOHO-5 scale is unidimensional across three datasets from Brazil and the UK.
- Partial scalar invariance was found between non-clinical datasets from Brazil and the UK.
- No scalar invariance was observed between clinical and non-clinical datasets.

## Abstract

Important psychometric approaches (structural validity, measurement invariance) remain underdeveloped in measuring oral health‐related quality of life, particularly for preschool children across diverse contexts.

This study aimed to evaluate the structural validity of the child's self‐reported version of the Scale of Oral Health Outcomes for 5‐year‐old children (SOHO‐5) and test the measurement invariance from cultural and clinical/non‐clinical comparison perspectives.

Three datasets were analysed: two from Brazil and one from the United Kingdom (UK). One Brazilian dataset was derived from clinical data collection (n
br‐cl. = 193), while the others were from non‐clinical epidemiological school‐based studies (n
br‐ncl. = 768, n
uk‐ncl. = 296). Dimensionality was tested through parallel analysis and confirmed by unidimensional indexes. Measurement invariance across datasets was tested via multi‐group Confirmatory Factor Analysis (CFA).

Unidimensionality was empirically confirmed for all three datasets. The multi‐group CFA tests reached partial scalar invariance threshold between the Brazilian and UK non‐clinical datasets. However, there was no scalar equivalence when comparing non‐clinical with clinical datasets, neither within Brazil nor between countries.

The child's self‐reported version of the SOHO‐5 is a unidimensional oral health‐related quality‐of‐life measure that is psychometrically comparable across different cultures (partial scalar invariance), but not between clinical and non‐clinical groups.