Reliability and validity of diagnostic nomenclature system of prosthetic dentistry

Purpose: The Japan Prosthodontic Society (a public interest incorporated association) proposed a new diagnostic nomenclature system method that is based on pathogenesis and etiology for providing adequate prosthodontic treatment to patients. This diagnostic nomenclature system is based on “factor” and “disability”, and assumes that a disability is caused by a factor. The aim of this study was to analyze the reliability and validity of several dentists’ diagnoses on mock patient charts. Methods: The Clinical Guideline Committee of the Japan Prosthodontic Society made mock patient charts and decided the disease name with the new diagnosis system. Fifty evaluators (prosthodontic specialists and hospital residents) answered the disease name with the new diagnosis system. The reliability and validity of the diagnoses were analyzed. Results: Krippendorff’s α, which evaluates the reliability, was 0.378 (prosthodontic specialists) and 0.401 (hospital residents). The value was 0.524 with the top 10 evaluators, and 0.628 with the top 2 evaluators. There was no difference between the prosthodontic specialists and hospital residents in the correct answer rate. The correct answer rate for common dental diseases was high and that for uncommon dental diseases was low. Moreover, there was no relation between the correct answer rate and answering time or years of experience. Conclusion: The reliability of the answers among all evaluators was not high, but it was high among the evaluators who showed a high correct answer rate in this study. The correct answer rate for common dental diseases was high and that for uncommon dental diseases was low.