Methods: Using a multistage stratified sampling, 597 schoolchildren aged from 13 to 18 years (mean age 14.9) living in the city of Isfahan, were recruited to complete the Persian COHIP questionnaire. They were also examined for dental caries and malocclusion by two trained calibrated examiners.
Results: Overall COHIP scores ranged from 15 to 135 (mean±SD=103.6±18). Sixty-six percent of the students experience at least one frequent oral health-related impact during the past three months. Cronbach’s alpha coefficient was 0.89 for overall score. Discriminate validity was supported by the significant difference between COHIP scores in the caries-free group and the others (p=0.01). Also, it was able to differentiate among the groups by various degrees of need to orthodontic treatment (p<0.01). Convergent validity was confirmed by significant association between the quality of life scores and the self-perceived health and oral health rating and self-perceived treatment need (r=0.36, 0.57, -0.40).
Conclusions: The Persian COHIP demonstrated acceptable psychometric properties for the descriptive purposes. Some discrepancies observed between the clinical data and quality of life status is confirmed by the perceptual identity of such indices which is influenced by several overt and covert variables.