Expert Validation of a Risk Calculator for Future Periodontal Disease

Successful application of the medical or wellness model of care to management of periodontal disease is dependent upon accurate and valid assessment of risk. We have developed a computer-based risk assessment tool, the Periodontal Risk Calculator (PRC) and evaluated its accuracy and validity. A group of 107 subjects manifesting a wide range of risk was assembled, and standard periodontal examinations performed. The resulting information was entered into the PRC and a risk score for each subject was calculated on a scale of 1 (lowest) to 5 for years 2 and 4 hence, assuming no intervention occurred. The PRC-assigned risk scores were compared to scores assigned to the same subject records by three groups of expert clinicians including 10 full time practicing periodontists (Group A), 6 periodontists selected from academe, the practice community and the US military (Group B periodontists), and 36 periodontally aware general dentists. The extent of variation among individual evaluators and evaluator groups, and the percent agreement of the calculated PRC scores with expert opinion were determined statistically. The extent of variation among individual periodontists relative to their group consensus was greater than expected, but was not different for periodontist groups A and B. Variation among general dentists was significantly greater than for periodontists. Periodontist Interclass Correlation Coefficients (ICC) for subjects=0.63-0.70 and for evaluators=0.06-0.07, while the general dentist ICC for subjects=0.53-0.55 and for evaluators=0.20-0.21. Percent agreement of PRC scores with expert clinician scores was good but not excellent (Weighted Kappa=0.44-0.49; Spearman Rank Correlation Coefficients=0.61-0.78). Periodontists consistently ranked more subjects in the low risk categories and fewer in the high risk categories than the PRC. Supported by Dental Medicine International, Inc.