Impact of administration mode on Oro-facial Appearance assessment using the Oro-facial Esthetic Scale.

Background: Oro-facial Appearance is increasingly recognised as an important component of patient-reported outcomes in dentistry. While the Oro-facial Esthetic Scale (OES) has sufficient psychometric properties to characterise dental patient's global assessment of Oro-facial Appearance, the equivalence of alternative methods of administration has not been demonstrated so far.

Objective: Aim of this study was to investigate whether and to what extent method of administration affects OES scores.

Methods: Participants were recruited as convenience sample of 42 adult dental patients registered for a regular recall visit and with no actual need of dental interventions. Oro-facial Appearance was assessed using the German version of the OES applying three methods of administration: (a) face-to-face interview, (b) self-administered questionnaire and (c) telephone interview, in a randomised order with a period of about one week between assessments.

Results: Oro-facial Esthetic Scale summary scores did not differ substantially or statistically significantly between the different methods of administration (two-way ANOVA; P = 0.209). Intraclass correlation coefficients (ICC) for pairwise comparisons of administration modes ranged from 0.67 to 0.84 indicating fair to excellent test-retest reliability. Internal consistency was satisfactory with lower limits of the 95% confidence interval (CI) of Cronbach's alpha ranging from 0.82 to 0.88 for the administration modes. Correlations of the OES summary score with a single item assessing global Oro-facial Appearance supported convergent validity with lower limits of the CI of the correlation coefficients ranging between 0.58 and 0.75.

Conclusion: The administration mode has no significant impact on Oro-facial Appearance assessment when using the OES.