Influence of administration method on oral health-related quality of life assessment using the Oral Health Impact Profile.

The influence of the administration method used to collect oral health-related quality of life (OHRQoL) data is largely unknown. Therefore, the aim of this study was to determine whether OHRQoL information obtained using the Oral Health Impact Profile (OHIP) differed with different methods of collection (personal interview, via telephone or as a self-administered questionnaire). The OHRQoL was measured using the German version of the OHIP. The instrument was administered to each of 42 patients using three different methods, in a randomized order, about 1 wk apart. The test-retest reliability coefficient for the repeated OHIP assessment across the three methods of administration, and the magnitude of the variance component for administration method, were determined, characterizing the degree of OHIP score variation that is caused by this factor. Whereas OHIP mean score differences of 3.9 points were present between administration methods, the reliability coefficient of 0.90 (95% CI, 0.85-0.95) indicated that 90% of the OHIP score variation was caused by differences between subjects (and not by the administration method or measurement error). The variance component for administration method explained 0.5% of the OHIP score variation. In conclusion, the method of administration (personal interview, telephone interview or self-administered questionnaire) did not influence substantially OHIP scores in prosthodontic patients.