Factor analyses of the Oral Health Impact Profile - overview and studied population.

Purpose: A desideratum of oral health-related quality of life (OHRQoL) instruments - such as the Oral Health Impact Profile (OHIP) - is that they accurately reflect the structure of the measured construct(s). With this goal in mind, the Dimensions of Oral Health-Related Quality of Life (DOQ) Project was proposed to investigate the number and nature of OHRQoL dimensions measured by OHIP. In this report, we describe our aggregate data set for the factor analyses in the project, which consists of responses to the 49-item OHIP from general population subjects and prosthodontics patients from 6 countries, including a large age range of adult subjects and both genders.
Materials and Methods: The DOQ Project's aggregate data set combines data from 35 individual studies conducted in Croatia, Germany, Hungary, Japan, Slovenia, and Sweden.
Results: The combined data set includes 10778 OHIPs from 9348 individuals (N=6349 general population subjects, N=2999 prosthodontic patients). To elucidate the OHIP latent structure, the aggregated data were split into a Learning Sample (N=5173) for exploratory analyses and a Validation Sample (N=5022) for confirmatory analyses. Additional data (N=583) were assigned to a third data set.
Conclusion: The Dimensions of Oral Health-Related Quality of Life Project contains a large amount of international data and is representative of populations where OHIP is intended to be used. It is well-suited to assess the dimensionality of the questionnaire.
(Copyright © 2013 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.)