Designing and psychometric evaluation of an Instrument to assess patient's satisfaction from communication with dentist and dental care services based on SERVQUAL model.

Background: Good communication between the patient and the dentist is one of the factors affecting patient satisfaction with the dental care received. The aim of this study was to design a Farsi instrument to determine patients' satisfaction with dental services and communication with the dentist based on the SERVQUAL model. The psychometric properties of the instrument were investigated on adult patients referred to the School of Dentistry at Tehran University of Medical Sciences.

Methods: Questionnaires related to the topic were searched in 2021, and the appropriate items based on the domains of the SERVQUAL model were extracted. The items were revised and completed to develop the initial version of the instrument. Face validity and content validity of the instrument were assessed. The content validity index (CVI) and content validity ratio (CVR) were calculated subsequently. Convergent validity was evaluated by calculating the correlation between the instrument's domains and the Dental Satisfaction Questionnaire (DSQ) using the Pearson correlation coefficient (PCC). Construct validity was examined by confirmatory factor analysis (CFA). Cronbach's alpha, intraclass correlation coefficient (ICC), and percentage of agreement were employed to check the tool's reliability in terms of internal consistency and reproducibility.

Results: The questionnaire had good content validity. (CVR ≥ 0.6, CVI ≥ 0.86), convergent validity (PCC of 0.68 between overall satisfaction based on the SERVQUAL instrument and DSQ, and construct validity (Goodness of Fit Index (GFI) = 0.83, Comparative Fit (CFI) = 0.92 and Root Mean Square Error (RMSE) = 0.006). The percentage of agreement of the items was in the range of %50-%76. The ICC for different domains of the instrument was estimated from 81 to 84%. Cronbach's alpha was 0.96.

Conclusion: The psychometric evaluation of the designed instrument showed that it was a valid and reliable tool in Farsi for determining the level of patients' satisfaction with the quality of dental services received and communication with the dentist.