The use of Subject Matter Experts in Validating an Oral Health-Related Quality of Life measure in Korean

OBJECTIVES This paper aimed to employ subject matter experts (SMEs) to assess the extent to which the Korean version of the short-form of the OHIP (OHIP-14 K) is culturally valid and equivalent in Korean. METHODS We approached 17 bilingual Korean SMEs from which 10 independently rated the clarity, relevance, and cultural equivalence of the OHIP-14 K. SME's varied between 10 and 41 years of clinical experience and were mostly males (# 7). We used Item-level Content Validity Index (I-CVI) to gauge the proportion of SMEs who considered the content of OHIP items (e.g., instruction, response format, etc.) to be culturally valid. We also performed additional analysis to determine the level of agreement between the SMEs. RESULTS The experts rated most of the items to be clear (S-CVI = 0.93) while having difficulties in assigning relevance of the questions to the expected domains (S-CVI = 0.42). Moreover, considerable disagreement existed among the experts in regard to the relevance (Kfree = 0.19 to 1.00) and the cultural equivalence indexes (ADM = 0.36 to 0.96). The content of the OHIP-14 K for the most part clearly reproduced the language of the original OHIP-14. However, experts disagreed on the relevance and conceptual equivalence of the OHIP-14 K for a Korean population. CONCLUSIONS Patient-oriented outcome measures such as the OHIP can be used across cultures once there are indeed assessing the same domains and constructs of interest. The CVI technique seems to be an alternative tool for evaluating content validity and equivalency of an OHQoL measure. A more refined, culturally relevant version of OHIP-14 K was proposed although there is no available data yet to support a better score validity, reliability and responsiveness of this proposed version.