Tooth retention as an indicator of quality dental care: development of a risk adjustment model

Retaining teeth improves oral health and quality of life. Thus, receipt of a root canal (vs. a tooth extraction) is a useful indicator of the quality of dental care. However, use of this quality measure without adjusting for the severity of oral disease could lead to spurious conclusions.

This paper describes the development of a dental severity adjustment methodology.

Retrospective study.

54,423 users of Department of Veterans Affairs (VA) dental care who had either root canal therapy or a tooth extraction at a VA facility in Fiscal year 1998.

International Classification of Disease Clinical Modification codes for dental diagnoses and comorbid medical conditions. We modeled the effects of dental disease severity in logistic regression models of the probability of receiving a root canal, using both conceptual and Modified Delphi-Panel derived models, adjusting for age, and medical comorbidities.

Conceptual and Modified Delphi models performed similarly. The dental disease severity adjustments increased the fit in models of the probability of receiving a root canal (C-statistic = 0.822 for the conceptual model and 0.804 for the Modified Delphi Panel model) compared with the model including comorbid medical conditions alone (C-statistic = 0.561).

Risk adjustment for dental disease severity improves the fit of models of the probability of receiving a root canal. Studies of the quality of dental care should consider employing risk-adjusted models.