Dr. Michael del Aguila and colleagues are to be lauded for their insightful utilization of a third-party insurer database for oral health care services research ("Patterns Of Oral Care in a Washington State Dental Service Population," March JADA). The attempts at validation of data also are noteworthy and clearly point out a factor that the authors did not mention in their conclusions. The retrospective review showed a presence of only a 50 percent agreement between patient records and paid claims data for emergency treatment services. This highlights the need for better documentation in record keeping for risk management of practitioners.
It should be pointed out that, while well conceived and executed, the study is limited in several areas by design. First, as the authors did report, this study represents the results of only patients with dental benefits in one state. Therefore, any extrapolation for purposes of generalizability or applicability to other states may not be representative of other populations, especially since there was no stated adjustment for factors of systemic fluoride exposure in the population.
Likewise, the authors acknowledged that "only one-third of the patients described in our study for 1999 were also patients of record in 1993" and "that the substantial number of new patients infused into the benefits system during the last decade was weighted toward those with more extensive restorative needs." To make this conclusion, one would need to have the numbers of credible vs. noncredible accounts added during this interval, information that the authors might have used, but was left out of the article.
The stated intent of the study in the Methods section was "to identify all procedures performed by dental professionals in all patients covered by WDS [Washington Dental Service] in 1993 and 1999." While laudable, the design of the study precluded such an outcome. The authors themselves acknowledge this fact by stating, "Dental benefits policies clearly have a major influence on both oral health and patterns of care."
For some reason, despite non-coverage of implant services in 1993, claims for these services were received and compared with claims for 1999 in which there was a respective increase from 0.03 to 0.08 percent. Contractually noncovered services in dental benefit plans do not require the submission of claims to the third-party administrator, except in some instances of reporting for capitated managed care programs.
It is entirely possible that the same level of implant services was being incurred in 1993 as in 1999, but not reported to the insurer, since they were not a covered benefit. Some practitioners seek to contain their overhead costs by not submitting claims to third-party carriers for contractually excluded services.
Likewise, it is unclear as to whether the levels of cosmetic services (such as porcelain veneers), which are contractually excluded services, have been excluded from the study.
Another factor affecting the reporting is the basic tenet of categorization of all amalgam restorations, resin-based composite restorations, inlays/on-lays, single crowns and endodontic treatment as being "treatment related to caries." This totally misclassifies traumatic injury as etiologic in any percent of these cases and would overstate the significance of carious etiology as a percentage of treatment costs.
While it is not stated in this study, most dental benefit plans are broken down into three types of services: Type I, preventive; Type II, routine services; and Type III, major restorative. The patients typically also incur dental coinsurance payments in the form of deductibles and copayments. The most typical plan has benefit coverage of 100 percent for Type I services, 80 percent for Type II services and 50 percent for Type III services.
Therefore, the 20 percent copayment for Type II services and 50 percent copayment for Type III services, as well as deductibles, would need to be included if this table were to be truly representative of patient expenditures as well as WDS.
In the evaluation of Figure 3, the authors state, "Expenditure patterns for oral surgery ... in 1999 reflect increases from 1993 in the number of impactions (most involving third molars), with a diminution in simple extractions particularly in the 13-to 18-year-old cohort." This analysis is truly reflective of the statistical numerical data. However, when interpreting this information it must be weighted not only by the statistical increase in demographic factors such as increase in total numbers of this age group leading to the bimodal distribution, but also by changing practice parameters and guidelines that affected the age group in question, such as progressive favorability for cosmetic outcomes of nonextraction orthodontic therapy.
While excellent in scope, there remain two large shortcomings of this study.
First, if "tooth loss is a primary measure of treatment outcome," it is a shame that the authors did not perform subclassification on the cohort of the one-third of the patients for whom they had longitudinal six-year data. In this manner, a more meaningful assessment of the value of expenditures for outcomes could be assessed.
Second, information regarding the financial factors of the surrounding economy during the specified intervals also would have provided a basis for rendering a more meaningful judgment as to the choices of treatment alternatives and distribution of services. Was the "observed shift in choice of restorative materials" a response to patient demand for more cosmetic procedures, or a shift in provider practice management to provide services with greater marginal profitability?
It is not only the presence or modification of benefits that affect treatments chosen or rendered, but also a mix of provider economics (such as increasing overhead costs of OSHA compliance for mercury wastes) and consumer availability of disposable income affected by inflation, employment security and general growth or recessionary general economic trends.
Despite these shortcomings, the authors are to be congratulated for highlighting the value of the provision of dental benefits to the population and profession. It only strengthens the relationship that provision of dental benefits increases the demand for oral health services.
