The External Validation Trial on the Diagnostic Accuracy of Self‐Reported Measures of Periodontal Disease

AIM: To externally validate a previously developed time- and cost-effective screening tool for screening subjects with different periodontal conditions by combining various questionnaires, demographic data and lifestyle factors, providing a reliable basis for future efforts to promote public awareness of oral/periodontal health and early periodontal care. METHODS: The study consisted of a self-administered questionnaire and a full-mouth periodontal and radiographic examination. External validation was conducted using a representative cohort systematically and randomly selected from the general population of Hong Kong. A modified questionnaire originally proposed by the Centers for Disease Control and Prevention/American Academy of Periodontology (CDC/AAP) was given to participants, and the results were tested against the periodontal case definition based on the 2017 World Workshop Classification of Periodontal Diseases. Accuracy was analysed by multivariate logistic regression, and the area under the receiver operating characteristic curve (AUROC) was calculated. RESULTS: A total of 384 subjects participated in this validation study, including individuals with periodontal health (6.2%), gingivitis (19.3%), Stage I/II periodontitis (19.3%) and Stage III/IV periodontitis (55.2%). The screening model, which integrated the CDC/AAP questionnaire with demographic and lifestyle factors, showed the best performance in detecting both periodontitis and severe periodontitis. For periodontitis detection, the model achieved an AUROC of 0.888, with a sensitivity of 91.1% and specificity of 90.0%. For Stage III/IV periodontitis, it showed an AUROC of 0.899, with a sensitivity of 88.8% and specificity of 77.2%. CONCLUSION: This externally validated model demonstrates acceptable accuracy in identifying periodontitis patients in independent populations, supporting its potential applicability across diverse community settings.