Concurrent validity of the COHIP.

OBJECTIVES: This study examined the relationship between children's perception of their OHRQOL and their perceptions of their dentofacial image, social anxiety, and self-concept as an assessment of the concurrent validity for the Child Oral Health Impact Profile (COHIP).
METHODS: A nonrandom, consecutive sample of children, ages nine to 14 years, was recruited for this observational validation study. Participants had been accepted for treatment in the University of North Carolina Graduate Orthodontic clinic. Data were collected after gathering initial orthodontic records and prior to delivery of any fixed or removable orthodontic appliances. Participants completed the COHIP and standardized dimension-specific questionnaires with known psychometric properties designed to assess self-concept, social anxiety, and perception of facial image. Child assent with caregiver consent was obtained prior to data collection. Pearson's correlations between each of the domains of the COHIP and the Dento-facial Image, the Social Anxiety Scale, and the self-concept domains of the Multidimensional Self Concept Scale (MSCS) were calculated. Criteria for support of concurrent validity was established based on directionality of expected relationships and strength of the observed correlation coefficient. Each correlation was assessed as meeting or not meeting the criteria. A one-tailed one sample Z-test was used to test the null hypothesis that 58% of the calculated correlations would meet the criteria (expected a priori) with an alterative that less than 58% would meet the criteria.
RESULTS: The average age of the 52 subjects enrolled was 11.8; 40% were male; and 85% were Caucasian. The hypothesis that 58% of the calculated correlations defined a priori as expected relationships would meet the criteria was supported by the data (P = 0.63). The perception of dentofacial appearance was positively correlated (range = 0.39 to 0.45; with all of the COHIP domains except for the School domain. Overall, the COHIP domains, particularly Self-Image and Social Emotional subscales, were positively correlated (0.32-0.52) with the MSCS self-concept domain scores, except Family Self-Concept. The COHIP domains, particularly Functional Well-being and Social Emotional subscales, were negatively correlated (-0.76 to -0.33) with the three Social Anxiety subscales that include both fear of negative evaluation and social avoidance.
CONCLUSIONS: The findings in this study lend support to the validity of the COHIP since 77% of the expected relationships between the domains of the COHIP and the domains of general, standardized dimension-specific instruments were observed. The decision to use condition-specific, dimension-specific, or general quality of life (QOL) measures is dependent on the purpose of the study. For investigations in children on the effect of dental treatments or in epidemiologic studies of an oral health outcome, the use of condition-specific QOL measures like the COHIP have the advantages of increased patient responsiveness since the assessment is focused on a specific condition, oral health, and increased sensitivity to treatment effects.