Factorial structure and cross-cultural invariance of the Oral Impacts on Daily Performances.

The issue of cross-cultural construct validation and measurement invariance of the Oral Impacts on Daily Performances (OIDP) questionnaire is important. Using confirmatory factor analysis (CFA), this study evaluated a proposed three-factor structure of the OIDP questionnaire in Tanzanian adolescents and adults and assessed whether this model would be replicated in Ugandan adolescents. Between 2004 and 2007, OIDP data were collected from 1,601 Tanzanian adolescents, 1,031 Tanzanian adults, and 1,146 Ugandan adolescents. Model generation analysis was restricted to Tanzanian adolescents, and the model achieved was tested, without modification, in Tanzanian adults and in Ugandan adolescents. A modified three-factor solution with cross-loadings improved the fit of the OIDP model to the data compared with a one-factor model and the original three-factor model within the Tanzanian [comparative fit index (CFI) = 0.99] and Ugandan (CFI = 0.98) samples. Cross-validation in Tanzanian adults provided a reasonable fit (CFI = 0.98). Multiple-group CFA demonstrated acceptable fit [chi(2) = 140.829, degrees of freedom (d.f.) = 24, CFI = 0.98] for the unconstrained model, whereas unconstrained and constrained models were statistically significantly different. Factorial validity was confirmed for the three-factor OIDP model. The results provide evidence for cross-cultural equivalence of the OIDP, suggesting that this measure is comparable, at least to some extent, across Tanzanian and Ugandan adolescents.