Dr. Segelman’s knowledgeable comments underscore the importance and challenges of research using these sorts of data, and offer suggestions for future efforts. This initial report is presented as the foundation on which such investigations can build to increase the knowledge of the practice of dentistry in an insured population.
We have begun a number of additional studies, including differences in patient care on the basis of fluoridated water systems. Preliminary results surprisingly show no differences, indicating the difficulty in isolating sources of fluoride in patients. Simply using the patient’s residential address is insufficient to judge whether he or she regularly receives fluoridated water.
Additionally, the reviewed literature clearly demonstrates that the use of fluoridated dentifrice washes out most of the treatment effect of water fluoridation. We also have investigations under way to look at individual patient and tooth outcomes, as well as oral health assessment, oral quality of life studies and other external factors that could affect practice patterns.
Dr. Segelman points out that providers will not always bill for procedures performed in an office, including implants and porcelain veneers. Though not reported in this article, our validation study found that 95 percent of procedures in the patient’s chart were recorded on the information stored in the data warehouse.
In our experience, most dental offices report all procedures, covered or not, as a way of documenting treatment for further communication with patients regarding their dental benefits and payment issues. In our experience, patients often request that procedures purportedly "not covered" be submitted to ensure an accurate interpretation of their benefits booklets. Thus, the intent of the study to report on procedures performed is fulfilled, irrespective of the influence of the reimbursement.
Dr. Segelman’s comments regarding traumatic injury resulting in restorative care underscore the need for more definitive definitions for service codes. We reported use of other procedure codes for emergency exams, which corresponded to a low proportion of overall treatment. While restorative treatment in young children is more likely a primary result of caries, the category is less clear for adult patients. The literature shows that approximately 60 percent of restorative services in adults younger than 65 years of age are rendered for replacement of existing restorations.
However, the reason most of those restorations were placed originally is probably related to caries. Other investigations of these data have shown that the single largest predictor of restoration replacement is seeing a different dentist, after adjusting for restoration size, material type and patient age.
With respect to Dr. Segelman’s concerns about reimbursement outcomes, we reported both patient copayment and third-party reimbursement as a single summed amount. This addresses differences in coverage for class of benefits as well. In all instances, the dollar figures include both these amounts. We also adjusted these values for inflation to make them comparable.
Additionally, we used the patients actually seeking care versus all eligible patients as the denominator. This helps control for increases in patient sample size from 1993 to 1999.
We agree completely that changes in patient preference, practice parameters and guidelines influence the data reported here.
