Thai Modified Dental Anxiety Scale (Thai-MDAS): cross-cultural adaptation, psychometric validation, and preliminary diagnostic accuracy.

Authors

Krit Rattanawonsakul, Rawikorn Krongvanitchayakul, Sittichoke Osiri, Sarat Suriyasangpetch, Pinsupa Hannongbua, Panupol Kunasarapun

Published in

BMC oral health. Volume 26. Issue 1. Aug 11, 2026. Epub Aug 11, 2026.

Abstract

Dental anxiety is a prevalent barrier to dental care worldwide. The Modified Dental Anxiety Scale (MDAS) is a widely used, brief self-report measure with established cross-cultural validity in numerous languages, yet no validated Thai-language version currently exists. This study aimed to cross-culturally adapt the MDAS into Thai (Thai-MDAS) and to evaluate the psychometric properties and diagnostic accuracy of the resulting Thai-MDAS.
The MDAS was adapted into Thai following the five-stage cross-cultural adaptation guideline, with permission from the original developer. A cross-sectional validation study was conducted among 233 Thai adults with English proficiency. Participants completed the Thai-MDAS, a Numerical Rating Scale (NRS), and the Index of Dental Anxiety and Fear (IDAF-4 C+) in its original English form. Internal consistency was assessed using Cronbach's alpha. Test-retest reliability was evaluated after four weeks using the intraclass correlation coefficient (ICC). Convergent validity was examined through Spearman's correlations with the NRS and IDAF-4 C+. Known-groups validity was assessed using the Mann-Whitney U and Kruskal-Wallis tests. Receiver operating characteristic (ROC) analysis determined diagnostic accuracy and explored preliminary cut-off thresholds for this population.
The Thai-MDAS demonstrated good internal consistency (α = 0.88; N = 233) and satisfactory test-retest reliability (ICC = 0.79; n = 156). Strong convergent validity was observed with the NRS (r = 0.74) and IDAF-4 C+ core module (r = 0.74). Known-groups analysis confirmed significantly higher scores among symptomatic dental attenders (p = 0.02) and participants with marked dental fear (p < 0.001), with no significant gender difference (p = 0.85). The area under the ROC curve was 0.94. At the original cut-off of ≥ 19, sensitivity was only 42.9%. Candidate thresholds in the range of ≥ 13 to ≥ 15 demonstrated more balanced diagnostic performance.
The Thai-MDAS is the first psychometrically validated Thai-language instrument for dental anxiety screening, demonstrating good reliability, strong validity, and preliminary outstanding diagnostic accuracy. Our findings suggest that the original cut-off of ≥ 19 may lead to the under-detection of anxious individuals in Thai populations, with lower thresholds showing promising diagnostic performance that warrants formal investigation. Validation in the general population, alongside prevalence exploration and cut-off optimisation, is recommended as a priority for future research.

PMID:
42732050
Bibliographic data and abstract were imported from PubMed on 13 Sep 2026.

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