In: Dental treatment18 Jan 2010
The 3 principal types of cost-effectiveness studies include (a) the cost-consequence model, (b) the cost-effectiveness model, and (c) the cost-minimization model. The cost-consequence model analyzes only the outcome of interest, under the assumption that there are no differences in costs. As an example, this model might be applied to a comparison of 2 dental materials where the cost of the materials and their application are relatively the same, but the outcome of interest is the material survival over time. The cost-effectiveness model examines the true cost-to-outcome ratio for the treatment and a comparator. Using a similar material science example, this model would be used in a study in which the restorative materials may differ in cost and survival. The cost-minimization model analyzes the cost differential between 2 treatments. The underlying assumption in this model is that the outcome of either treatment will be equal or similar. Using the material science example, the cost-minimization model would compare the costs of the restorative materials under the assumption that the materials performed the same over time.
This pilot study used a cost-minimization model for outpatient GA versus oral CS. This investigation relied on each individual patient as the unit of analysis and each patient contributed cost data. The analyses used evaluated the societal costs, defined as the sum total of direct, indirect, and opportunity costs. Cost analyses usually use mathematical, estimation, or simulation modeling. In this study, the GA model relied on primary data and the CS model was an estimation model. viagra soft
The sample included 22 children who required pharmacologic management for dental treatment because of short-term situational anxiety in the conventional dental environment. All were scheduled for treatment using GA because their parent or guardian opted for this modality of care. The patients’ ages ranged from 24-60 months at the time of the GA appointment. All were healthy children with no contraindications for routine dental care. All met requirements for American Society of Anesthesiologists class I anesthesia risk.
To maintain consistency and reliability, all patients were treated by the same dental operator in the GA setting. The patient sample served as its own comparison group to an estimation model for CS treatment.
Panel of Experts
Expert judgment and consensus panels involve synthesis approaches used to estimate probabilities, costs, preference weights, and other variables in cost-effectiveness studies. For this study, a panel of 4 experts was used to determine values in the CS estimation model that could not be obtained from actual data. The panel consisted of 2 experts each in the areas of CS and GA. The experts were selected based on their extensive research and clinical experience. All were board-certified pediatric dentists who each have 20-25 years of clinical practice experience in the specialty.
Relative Based Value Units
The treatment rendered was assessed using the dental relative based value units (RBVUs). The RBVUs are based on the time and difficulty of procedures. The RBVU system has been used in medicine for many years as a way to value medical procedures across disciplines and specialties. The dental RBVU system was developed in 1985 to equate dental procedures. Normal distribution and SDs and means were used to develop the scale. The data were analyzed for validity, statistically normalized, and weighted.
The RBVUs (Table 1) are considered to be valid and reliable measures of dental procedures. They are used widely by health insurance organizations such as Aetna, Blue Cross/Blue Shield, Prudential, and Delta Dental, as well as Medicaid agencies in Vermont, Kentucky, and South Dakota, to determine the value of procedures.
Table 1. Examples of RBVUs for Selected Dental Procedures
|Posteroanterior x-ray examination|
|Bitewing x-ray examination|
|1 surface amalgam, primary||2110||1.0|
|1 surface resin, primary||2330||2.0|
|Stainless steel crown||2930||4.0|
To equalize treatment for the GA and CS models, RBVUs were calculated from the treatment rendered for the 22 children during their GA appointment. The same RBVU data for the GA appointment were used in the CS estimation model, so dental procedures were equal in both models. To determine the number of CS appointments to equate the same RBVUs rendered under GA, this study relied on the clinical judgment of the same operator who completed the 22 GA cases. This approach allowed us to control for operator speed and judgment in determining the number of CS appointments that a given child might need. canadian pharmacy cialis
Models used in this study were taken from the societal perspective. This approach relies on the perspective of the decision maker, which in this study was the parent or guardian. The cost models included costs incurred by the family for treatment and opportunity costs. Gus-ten and colleagues define opportunity costs as income forgone for the decision of treatment. The accounting data included both indirect and direct costs.
Data for cost models were collected from hospital and dental school accounting records for the patients. There are many ways to calculate opportunity costs; for the purposes of this study, an aggregate measure was used.
Income data by county were obtained for 1997 fiscal year from the Economic Policy Unit of the North Carolina Department of Commerce. The average wage earnings for each adult’s county of residence were used to calculate lost income. In summary, opportunity costs in the model were calculated by multiplying the aggregate family wage earnings by the total hours lost because of the child’s dental treatment.
Assumptions Underlying Model Development
This study relied on the cost-minimization model for using GA versus CS. In cost analysis studies, many assumptions must be made to develop a model. For the GA model, this investigation relied on the panel of experts to estimate the parental time commitment for a preoperative GA visit (4 hours) and for the GA appointment itself (8 hours). For the number of adults accompanying the child for appointment procedures, the actual numbers were used, either 1 adult or 2 adults, depending on who accompanied the child.
For the CS model, the panel of experts estimated that the preappointment physical examination would require 4 hours and that only 1 parent would accompany the child for this appointment. For the CS new patient examination, they reached a consensus that this appointment would require a 2-hour appointment and that 1 parent would accompany the child. Finally, they estimated that 2 adults would accompany their child for their CS appointment and a 4-hour time commitment would be required for each sedation visit.
Cost of GA
The cost of GA is determined by the following formula:
(Qotal = Q>creen + Cpreop + C^ + CUmhr + CaddV4hr Хг + Qnesth + Crec + Cpt/family). For the GA model, the cost ($22) of screening (C^J was obtained from dental school records. The cost ($88) for the preoperative medical appointment (Cpreop) was obtained from the hospital accounting records for the preoperative GA evaluation. The actual dental fees for the procedures rendered under GA were used for the cost of treatment (CJ. This cost was equalized to the CS model using RBVUs. The hospital cost for the GA appointment (Clst%hr and Cadd%hr) was obtained from the hospital accounting records generated for each patient. Because hospital fees vary from the first half hour ($950) to each additional half hour ($530), 2 separate variables were used. The variable representing the cost of each additional half hour (C^d^h,.) was multiplied by the time beyond the first half hour (Xx). The cost of the anesthesia (Qmesth) was $145 for the first 30 minutes and $73 for each additional 30 minutes. The recovery room (Crec) costs were $110 per hour. The operating room time was obtained from hospital records. Apcalis Oral Jelly
The opportunity cost for each patient was calculated by average income for the county of residence multiplied by the time lost for treatment per adult. Opportunity costs were calculated for both the preoperative and GA appointments. All hospital accounting information was obtained from the Office of Cost Accounting at the University of North Carolina Hospitals.
Cost of CS
The cost of CS is determined by the following formula:
(Qotal = ^screen Qipe Cppe Qx Qjppt ^2 Qappt X3 + Cpt/famiiy)- The cost ($22) of the screening appointment (С^еп) and the cost ($22) of the CS new patient examination (Cnpe) were obtained from dental school fees. The estimated cost ($88) of the physician’s physical evaluation (Cppe) for CS examination was obtained from the University of North Carolina ambulatory care unit.
As noted already, the panel of experts estimated the time it took for a CS new patient examination, the physician’s preoperative physical examination, and the number of adults accompanying a typical child to preoperative appointment and sedation appointments. This information was necessary to quantify the opportunity cost for each family (Cpt/family). To estimate the opportunity cost for each sedation appointment, the average income for the county of residence was multiplied by total time lost due to all phases of treatment for each adult accompanying the child. The CS appointment length was estimated at 60-90 minutes by the consensus panel.
The cost of each sedation appointment (Cappt) was defined as the fee charged by the dentist to perform the CS procedures. This fee ($250) reflects a charge for sedation medications, monitoring equipment, and additional personnel dedicated to monitor and assist in the CS area. The Cappt was multiplied by the number of appointments (X2) estimated for the same treatment to be completed under CS as was completed under GA.
As noted previously, the estimated number of CS appointments needed for each child was made by the same dental operator who completed the actual procedures in the operating room for the GA model. This approach allowed the control for the variable clinic speed. Furthermore, the dental operator who made this judgment had extensive experience in the sedation arena. She made these judgments on estimated CS appointments needed on the basis of the patient’s treatment plan, quadrants of care needed, and the patient’s body weight. Body weight was used because this vari able must be considered for the amount of local anesthetic used in a given visit. generic cialis uk
After the number of CS appointments was determined, the probability that the patient would need to return for another appointment because CS was aborted due to patient behavior was then estimated. This abortion rate (X3) in the Pediatric Sedation Clinic of the Department of Pediatric Dentistry at University of North Carolina at Chapel Hill is 5.6%.n The cost of actual dental treatment (CJ was equalized to GA treatment using RBVUs.
The study’s first aim was to establish costs representative of the societal costs for treatment under GA and CS. This was accomplished using a combination of opportunity cost and accounting data that represent direct and indirect costs.
The study’s second aim was to establish the relationship between dental treatment rendered and total costs. Ordinary least squares regression analyses were used to examine the association between societal costs of treatment and RBVUs. The outcome measure was the societal costs of treatment, and the major explanatory variable was treatment need as measured by RBVUs. Two regression models were used: Cost for GA = p0 + pi (RBVUs) and Cost for CS = a0 4- аг (RBVUs). The first equation illustrates the relationship between total costs and RBVUs for GA, whereas the second illustrates the same association for CS.
The study’s third aim was to determine the relationship between the GA and CS models. The 2 regression equations were plotted against each other, and the relationship of the predicted regression equations illustrates the association between the GA and CS models. STATA Statistical Software was used for all the data analyses.
Blog invites submissions of review articles, reports on clinical techniques, case reports, conference summaries, and articles of opinion pertinent to the control of pain and anxiety in dentistry.