Psychometric properties and criterion validity of a Spanish version of the Scale of Oral Health Outcomes for 5-year-old children (SOHO-5) for a public school sample from the Dominican Republic

Objectives: To assess the psychometric properties and criterion validity of a Spanish version of the SOHO-5 quality of life scale for 6 and 7 year old children attending a public school in the Dominican Republic.
Methods: Sixty-nine children aged 6 and 7 years were examined using the International Caries Detection and Assessment System (ICDAS) criteria and were administered an adapted Spanish version of the SOHO-5. A total caries lesion score was computed by selecting the worst ICDAS score for the child. ICDAS codes 0, 1 and 2 were re-codified as sound or initial lesions (code 0), ICDAS codes 3 and 4 moderate lesions (code 1) and ICDAS codes 5 and 6 as extensive lesions (code 2).
Results: The sample was comprised of 35 girls and 34 boys, with 38 aged 6 years and 31 aged 7 years. According to the intraoral examination, 15.9% of the children had sound or initial lesions, 10.1% had moderate lesions, and 73.9% had extensive lesions. A confirmatory factor analysis of the theoretical 1-factor structure of the SOHO-5 using a categorical variable estimator over polychoric correlations achieved an excellent fit to the data (χ = 13.21, df = 14, p = 0.60; CFI = 1.00; TLI = 1.00; RMSEA = 0.00), with all 7 items obtaining high factor loadings (> 0.70). In addition, the scores of the SOHO-5 attained very good reliability according to Cronbach’s alpha (α = 0.85). Finally, a structural equations model revealed that the latent scores of the SOHO-5 were able to explain 36.8% of the variance of caries lesion scores (γ = 0.61, p < 0.001).
Conclusions: The Spanish SOHO-5 scale shows excellent psychometric properties. This instrument is easy and fast to administer and has good criterion validity related to caries lesions.