RESUMO
BACKGROUND: Patient satisfaction is a central topic in quality management in outpatient dental care. The ZAP questionnaire was validated to explore patient satisfaction in general and specialist outpatient settings. This study aims at assessing the psychometric properties of the ZAP in dental care. METHODS: A minimally modified version of the ZAP consisting of 4 domains (office organisation, cooperation, interaction, information) was administered in personal interviews to a population-based sample. Descriptive, exploratory and confirmatory psychometric analyses were conducted with random subsets of the study sample. RESULTS: The study population comprised 1 773 subjects with at least one dental visit during their lifetime (mean age=50 years, female=51.6%). The exploratory factor analysis identified 3 subscales (office organisation, interaction, information). Based on these results, items of the subscale "cooperation" were excluded from further analyses. The remaining items had a medium difficulty of 0.75, all item-total-correlations were above 0.4. Missing values ranged between 2.3% and 28.7%. Cronbach's alpha ranged between 0.79 and 0.95. After introduction of 3 residual correlations, the confirmatory factor analyses reached a good model fit (TLI: 0.97; CFI: 0.97, RMSEA: 0.06). Partial standardised factor loadings ranged between 0.77 and 0.87. The 3 latent factors were highly correlated. There was a positive correlation between the 3 subscales and global patient satisfaction with the dentist. CONCLUSION: The psychometric assessment can be used in the 3 modified subscales (office organisation, interaction, and information) to assess patient satisfaction with dental care. To assess dentist's competence in relation to dental anxiety and pain as well as shared decision making new scales specific to dental care should be explored.
