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Biomedical subjects

D Grembowski

Publications and source records attributed to D Grembowski.

At least 37 records · Page 2Linked to original sources
PubMed1990

A small area simulation approach to determining excess variation in dental procedure rates.

All small area analyses need to compare the observed variability in rates to that expected by chance alone, but the expected variability is usually not known. This paper uses patient-level data for five dental procedures to simulate the distributions of the summary statistics that are usually generated in such studies. These statistics are found to vary greatly even under the "null hypothesis" that all dentists are using procedures at the same rates. The simulated dentist rates are compared to observed rates obtained in a different study. These findings illustrate problems that can occur in small area analysis studies, and emphasize the importance of using statistical techniques that are appropriate for the data that are to be analyzed. Investigators should make every effort to obtain patient-level data, or at least to understand the underlying distribution of the number of procedures per patient, to avoid mistaking significant deviations from an incorrect model as evidence for significant variation among small areas.

Analysis of Variance↗
PubMed1988

The structure and function of dental-care markets. A review and agenda for research.

The growth of dental health services over the past 15 years has produced several issues in dentistry. Because economic markets are the cornerstone of dental delivery in the US, informed responses to these issues require a thorough understanding of dental-care markets. The empirical literature is reviewed to examine the structure of dental markets, to assess the major determinants of market equilibrium, and to examine the social and health consequences of dental-care markets. Results reveal that while dental markets are imperfectly competitive, it is unclear whether prices exceed competitive levels. Little is known about the effects of dental markets on public oral health and society. Future research is proposed in two broad areas: 1) updating early studies conducted when few Americans had dental insurance benefits; and 2) path-breaking research to advance our knowledge of dental-care markets in particular and medical-care markets in general.

Community Participation↗
PubMed1988

The influence of dentist supply on the relationship between fluoridation and restorative care among children.

Because fluoridation effectively reduces dental caries among children, it may also reduce their demand for dental care. The authors tested this proposition among 985 insureds aged 9 to 14 in Washington State using dental claims from 1982 to 1985. In the sample almost two thirds of the children with continuous fluoridation exposure lived in markets with the smallest number of persons per dentist. Relative to other children, these children received more diagnostic and preventive services and had the highest probability of receiving restorative care. Among children who received restorations, children in this group had the fewest restorations. While the last result reflects expected reductions in caries due to fluoridation, the others may reflect providers' response to less tooth decay and increased competition for patients.

Adolescent↗
PubMed1988

Measuring length of exposure to fluoridated water.

Previous studies have measured subjects' exposure to fluoridated water in two ways: number of years exposed to fluoridation and a dummy variable indicating the fluoridation status of the subjects' present community. The former assumes that fluoride concentrations of water supplies are constant across years, while the latter assumes subjects have never changed residences. Measurement error may occur when either assumption is not satisfied. These two sources of error may be reduced in a newly developed measure of lifetime fluoridation exposure (LFE) containing residence history and fluoride level elements. The aim of this paper is to examine the accuracy of the three measures. Results reveal that the number of years measure and LFE are highly correlated (0.98) and have similar effects in a regression model, indicating both are valid measures of fluoridation exposure. LFE also appears to be fairly insensitive to measurement error due to inaccurate recall of residence histories. Measuring fluoridation exposure with a dummy variable is not recommended.

Adolescent↗
PubMed1988

Factors influencing dental decision making.

In clinical decision making, dentists routinely choose between alternative treatments such as crown vs amalgam/composite buildup, root canal vs extraction, fixed bridge vs removable partial denture, and prophylaxis vs subgingival curettage or periodontal scaling. A number of technical and patient factors can influence dentists' choice of treatment in these situations; however, little is known about their relative importance. To address this issue, a list of technical (e.g., periodontal status and caries rate) and patient (e.g., cost and patient preference) factors possibly influencing choice of treatment was developed for each pair of services. Responding to a mail questionnaire, 156 general dentists in Washington State listed the top three factors influencing their choice of service in each pair. Results revealed that dentists took different factors into account in choosing among alternative treatments. Technical factors dominated over patient concerns; only about 33 percent of the dentists considered patient factors important in choosing alternative therapies. The latter group was less preventively oriented, were solo practitioners, worked longer hours, and had lower prices. Results suggest patients may have little influence on prescriptions of therapy among experienced general dentists.

Attitude of Health Personnel↗
PubMed1987

Dental care demand among children with dental insurance.

As the number of families with dental insurance and expenditures for dental care has increased over the past two decades, so has interest in determining cost-sharing effects on dental demand among insureds. Using a representative sample of Pennsylvania Blue Shield children insureds during 1980, we estimate cost-sharing effects on dental demand for basic (diagnostic, preventive, restorative, endodontic, and extraction services) and orthodontic care. Results indicate that cost-sharing has little influence on the probability of using any dental services and basic expenditures. However, the probability of using orthodontic services decreases 2.1 percent when the proportion of orthodontic expenditures paid by the parent increases 10 percent. By reducing the cost of care, cost-sharing reduces social class differences in dental demand common in unisured populations, likely producing public oral health benefits.

Child↗
PubMed1987

Dental care demand: insurance effects and plan design.

This study concentrates on an important health policy question: the impact of dental insurance on the demand of adults for dental services. Demand equations for individuals are estimated from a systematic random sample of 4,173 families with complete information on their dental claims (insured through Pennsylvania Blue Shield) and survey data. The principal contributions of the research are twofold: (1) to provide rigorous, large-sample estimates of the demand for dental services of insured individuals--providing a complementary set of "natural" experiment results to the randomized experiment results of the RAND Health Insurance Experiment--and (2) to estimate the incremental effects on dental care demand of certain factors related to adverse selection. The study is a companion to a previously published study of children by the same authors. Generally, the analysis shows relatively small money price elasticities of dental care demand among this insured adult population (ranging from -.01 to -.266 across specific types of service). Given a finding that total expenditures for Basic services are 37 percent and 90 percent higher, respectively, for community-rated (versus experience-rated) primary subscribers and insureds, we conclude that differential adverse selection between community- and experience-rated groups accounts for significant differences in dental demand.

Adult↗
PubMed1986

Coinsurance effects on dental prices.

For many Americans the cost of dental services represents a barrier to receiving regular dental care and maintaining proper oral health. The recent growth of the dental insurance industry, however, may partly offset this price barrier among insureds. Our purpose is to examine the relationship between coinsurance and dental prices for 16 dental services among a sample of Pennsylvania Blue Shield (PBS) adult insureds. The dependent price measure is the annual average gross price paid for 16 specific preventive, restorative, periodontic, endodontic, prosthodontic, and surgical dental services. Independent variables in the price model include the insured's age, education, coinsurance rates, time costs, market area, non-wage income, oral health status, area dentist-population ratio and usual source of care. Data sources are 1980 PBS claims and coinsurance rate data and a mail survey of sampled insureds. OLS regression analysis reveals that the model's independent variables explain little dental price variation. No variable is consistently significant across services, but market area, coinsurance rates, and time costs alternately dominate across equations. These results suggest that, among adult insureds, coinsurance and time costs influence dental fees in a minority of dental services. Insurance reduces the patient's sensitivity to money price, and non-price factors correspondingly seem to become more important in patient search.

Adolescent↗
PubMed1985

Utilization of dental services in the United States and an insured population.

Dental service utilization rates among 1.2 million Pennsylvania Blue Shield dental insureds are compared to rates in the US population. Insurance appears to stimulate the utilization of dental services above national norms; children appear to be a major beneficiary of insurance's incentive effect on dental service use. The implications of these findings for health planners and dental insurance providers are discussed.

Adolescent↗
PubMed1984

Insurance effects on employer group dental expenditures.

As the number of dental insureds and the amount of insured expenditures have increased over the past decade, so has interest in determining insurance effects on dental demand among employer groups and their insureds. Using Pennsylvania Blue Shield (PBS) employer group data representing 50-65% of all PBS insureds, the authors estimate the own-effect of basic insurance rates (diagnostic, preventive, restorative, endodontic, extraction services) and the cross-effects of riders A (crowns and oral surgery), B (prosthodontics), C (periodontics), and D (orthodontics) insurance rates on annual basic expenditures for 1975-1979. Results indicate a consistently positive relationship between basic insurance rates and expenditures. Orthodontic insurance rates have positive cross-effects on basic expenditures, suggesting basic-orthodontic complementarities. Although not statistically significant, potential substitution relationships may exist between basic and oral surgery, prosthodontic, and periodontic services. The implications of these findings for plan design and public oral health are discussed.

Blue Cross Blue Shield Insurance Plans↗
PubMedDate not supplied

A community strategy for Medicaid child dental services.

OBJECTIVES: The authors present second-year utilization data and first- and second-year cost data for a community-based program in Spokane County, Washington, designed to increase access to dental care for Medicaid-enrolled children from birth to 60 months of age. METHODS: The authors used Medicaid eligibility and claims data for 18,727 children 5 years of age and younger to determine utilization of dental care from January 15, 1996, through January 15, 1997. They also used accounting records from the agencies involved to calculate the first- and second-year costs of the program. RESULTS: A child in the ABCD program was 7.2 times as likely to have at least one dental visit as a Medicaid-enrolled child not in the program. Estimated costs per child with at least one dental visit (in 1995 dollars) were $54.30 for the first year and $44.38 for the second year, or $20.09 per enrolled child for the first year and $18.77 for the second year. CONCLUSION: Public-private joint efforts are effective in improving access to dental care for Medicaid-enrolled children.

Child↗