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

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.

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

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.

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.

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