Development of a shortened Japanese version of the Oral Health Impact Profile (OHIP) for young and middle-aged adults

The aim of this paper is to develop a short version of the Japanese OHIP (OHIP-J) appropriate for use in young and middle-aged adults, and to evaluate its properties using cross-sectional data.

A study population of 8,658 workers aged 20-59 years rated their oral health by means of a self-administered questionnaire. Using a factor analysis approach, a shortened version of OHIP-J was derived. Internal consistency, floor effect, and construct validity were determined.

We derived a subset of 18 items from OHIP-J (OHIP-JA18), grouped into four subscales: "functional limitation", "physical pain", "psychological discomfort", and "disability & handicap". All four subscales had acceptable internal consistency (Cronbach alpha > 0.79). OHIP-JA18 demonstrated an acceptable floor effect, which was determined by the proportion of subjects who obtained a 0 score (< 30%); however, the floor effect of the ordinary shortened version based on OHIP-14 (OHIP-J14) was not acceptable. We confirmed the conceptual framework of OHIP-JA18 that "disability & handicap" is affected by "functional limitation", "physical pain" and "psychological discomfort", because the model fitted the data moderately well by structural equation modeling (SEM) analysis (GFI = 0.90, RMSEA = 0.08).

OHIP-JA18 demonstrated acceptable measurement parameters to justify its use in outcome assessment for oral health related quality of life (OHQOL) in young and middle-aged adults in Japanese workers. Further studies will be needed to evaluate an intervention such as worksite health promotion.