Comparison of a generic and a specific measure of oral health related quality of life

OBJECTIVES: The aims of the study were to compare the discriminant validity of a generic health state measure, the EuroQol, and a specific oral health measure, the Oral Health Impact Profile. PARTICIPANTS: Patients treated by a random sample of South Australian dentists. BASIC RESEARCH DESIGN: Data were collected in 2001-02 using mailed self-complete questionnaires. Dentists recorded the diagnosis of dental conditions and provided patients with self-complete questionnaires to record the nature, severity and duration of symptoms using the EuroQol (EQ-5D+) and 14-item version of the Oral Health Impact Profile (OHIP-14) instruments. Data were available from 375 patients (response rate = 72%). MAIN OUTCOME MEASURES: Three measures (simple counts, additive scores and scale scores) were used for each instrument and compared by oral health, patient demographic and visit factors, and main presenting dental condition. RESULTS: Across all three measures the OHIP-14 was associated with the oral health factors of dentate status, number of teeth, denture wearing and number of decayed teeth while the EuroQol was associated with decayed teeth. For patient demographics both the EuroQol and OHIP-14 were associated with age of patient. For visit factors both the EuroQol and OHIP-14 were associated with visit type and insurance status, while only the EuroQol was associated with time since last visit. Both the EuroQol and OHIP-14 were associated with main dental condition. CONCLUSIONS: There was little difference in the number of associations of either EuroQol or OHIP-14 scores regardless of whether simple counts, additive scores or scale score measures were used. In bivariate analyses the OHIP-14 was more sensitive to oral health factors, but the EuroQol performed as well or better than the OHIP-14 for patient demographics, visit factors and main dental condition, and was associated with the oral health factor of number of decayed teeth. Both measures performed similarly in multivariate analysis.