Validation of the Korean version of the oral health impact profile among the Korean elderly

Objectives: This study aimed to validate a Korean version of the oral health impact profile (OHIP) and to develop a short-form of OHIP for the Korean elderly. Methods: The original English version of OHIP was translated into Korean using a forward-backward method. Internal consistency was measured by Cronbach's alpha among 1098 subjects aged 56 or more. Test-retest reliability was assessed by intraclass correlation coefficients (ICCs) with a 3-month interval among 155 subjects aged 57 or more. The validity of the Korean version of OHIP (OHIP-K) was assessed by comparing OHIP scores with the perceived dental treatment needs and by identifying associations between OHIP scores and the number of natural teeth among 128 subjects aged 54 or more. The short-form of OHIP for the Korean elderly (OHIP-14K) was developed using linear regression models and was also validated and compared with the short-form of OHIP by Slade (OHIP-14S). Results: The Cronbach's alpha value for OHIP-K was 0.97. The ICC for OHIP-K was 0.64. Adults with perceived dental treatment needs had a higher OHIP score than adults without any such needs (P < 0.001). The number of natural teeth was negatively associated with the OHIP score (r = −0.44, P < 0.001). OHIP-14K and OHIP-14S shared seven identical items out of a total of 14 items. OHIP-14K results correlated with OHIP-K almost exactly (r2 = 0.96), as did OHIP-14S (r2 = 0.95). Conclusions: OHIP-K showed excellent reliability and validity. OHIP-14S may be a better choice for the evaluation of oral health-related quality of life among the Korean elderly for an international comparison