A comparison of the validity of generic- and disease-specific measures in the assessment of oral health-related quality of life

In recent years, a number of instruments have been developed to measure the outcomes of oral disease. The Oral Health Impact Profile (OHIP) is the most sophisticated and comprehensive measure developed to date. At present, reports of the use of this measure are confined to descriptive population studies. Objectives: The aim of this study was to compare the validity of the OHIP with a generic health-related quality of life measure, the SF36. Methods: Study subjects were in three groups, namely, edentulous patients seeking dental implants ("implant subjects", n=32), edentulous patients seeking conventional dentures ("edentulous control", n=35) and dentate patients ("dentate control", n=21). All subjects completed an OHIP and SF36 prior to receiving any treatment. The edentulous subjects also completed a subjective assessment of satisfaction with their existing conventional dentures. OHIP data were computed using the simple count and weighted scores methods. Results: The median number of negative impacts reported for each group was: 17 (implant subjects), six (conventional control) and one (dentate control). OHIP sub-scale scores were significantly higher (P<0.001) for implant subjects than control subjects. There were no significant differences between the SF36 sub-scale scores. There was a significant correlation (P less than or equal to 0.01) between aspects of satisfaction with conventional dentures worn by the edentulous subjects and OHIP sub-scale scores. Correlations between denture satisfaction variables and SF36 scores were not significant. Conclusions: It was concluded that the OHIP shows good discriminant and construct validity properties. As it is oral specific, it will be of greater use in measuring outcomes of oral disorders than generic measures such as SF36. This finding will be relevant when considering the use of health-related quality of Life measures to target resources and measure the outcome of clinical intervention.