Comparison of the COHIP and OHIP-14 as measures of the oral health-related quality of life of adolescents

Aim: To compare the validity and reliability of the Oral Health Impact Profile-14 (OHIP-14) and the Child Oral Health Impact Profile (COHIP) for investigating oral health related quality of life (OHRQoL) of adolescents. Method: We studied 234 adolescents from two publicly funded schools in Hamedan, Iran. Participants completed questionnaires and had a clinical examination. We compared convergent and discriminative validity of the instruments by analyzing their association with self reported health indicators and number of decayed teeth. Results: Both instruments showed good convergence with self-rated health and self-rated oral health. Those who perceived dental treatment needs, who had experienced dental pain in last month, were more dissatisfied with their oral health, or had more decayed teeth scored higher on both OHIP-14 and COHIP. The discriminative validity of the two instruments varied slightly and inconsistently. The convergent and discriminative validity of both instruments were established independent of their scoring methods. Conclusion: Both the OHIP-14 and COHIP were valid and reliable measures for investigating OHRQoL among 15-17 year old adolescents. The COHIP is preferable when the aim is identifying more impacts. Both measures have shown good convergent and discriminative validity, however, for practical reasons; the shorter instrument (OHIP-14) may be more suitable for epidemiological studies.