Abstract
Background
Although Medicaid expansion aims to eliminate financial barriers to health care for low-income people in the United States, health care accessibility cannot be guaranteed without clinicians who provide health care to Medicaid recipients. This study examined the characteristics of Indiana dentists that are associated with the likelihood of participating in Medicaid after expansion in 2015.
Methods
This study included Indiana-licensed dentists who renewed their licenses in 2018 and provided supplemental data elements related to demographics, education and training, and professional characteristics. Dentists’ Medicaid engagement behavior was categorized on the basis of when claims were submitted from 2014 through 2017. Statistical analyses included the χ2 test and generalized multinomial logit model.
Results
Overall, 2,037 Indiana-licensed dentists were included in the study. Of these, 802 (39.4%) were continually active in Medicaid during the study period, and 116 (5.7%) became active after expansion. Dentists had a greater likelihood of engaging in Medicaid after expansion if they were female, specialized in oral and maxillofacial surgery, practiced in a group practice, and were located in a rural county.
Conclusions
This study shows that dentists with certain demographic and practice characteristics had a greater likelihood of participation in Indiana Medicaid after expansion in 2015. Several findings from this study are consistent with previous research regarding the emerging trends in workforce diversity and show the impact of expansion policies on the dental safety net.
Practical Implications
This study presents an effective framework for the use of administrative and regulatory data sources for state-level analysis of the Medicaid safety net.
Key Words
Abbreviation Key:
FPT (Federal poverty threshold), HIP (Healthy Indiana Plan)
- Lindner S.
- Levy A.
- Horner-Johnson W.
,
- Tipirneni R.
- Rhodes K.V.
- Hayward R.A.
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Provider capacity has implications for health care accessibility after expansion, especially for the dental safety net in which accessibility is strongly correlated with the number of dentists participating in Medicaid.
- Wehby G.L.
- Lyu W.
- Shane D.M.
,
- Buchmueller T.
- Miller S.
- Vujicic M.
,
- Guth M.
- Garfield R.
- Rudowitz R.
Historically, dentists have had lower rates of participation in state Medicaid programs than physicians, with disparities in service reimbursement being the greatest contributing factor.
Medicaid fee-for-service (FFS) reimbursement and provider participation for dentists and physicians in every state. In: American Dental Association, ed. 2016.
Moreover, while federal rules require state Medicaid programs to cover comprehensive dental services for children, dental benefits provided to adults have varied widely across states.
The Patient Protection and Affordable Care Act (PPACA), Pub L 2010; 111-148, 124 Stat 119.
The most common dental services covered under adult state Medicaid benefits are emergency treatments, whereby less than one-half of states cover extensive dental services.
coverage by state. Center for Health Care Strategies.
However, as a result of the Patient Protection and Affordable Care Act of 2010, many states have expanded Medicaid programs, resulting in coverage for a greater number of low-income adults, including, in some cases, dental service coverage.
- Wehby G.L.
- Lyu W.
- Shane D.M.
,
- Freedman S.
- Richardson L.
- Simon K.I.
,
- Sommers B.D.
- Blendon R.J.
- Orav E.J.
- Epstein A.M.
Given that Medicaid expansion of dental coverage has occurred in numerous states and is being considered in federal discussions regarding Medicare, studies examining the relationship between expansion of public insurance programs and dentist participation are particularly timely.
Medicare Dental Benefit Act of 2021, HR 502-117th Cong (2021-2022). February 2, 2021.
,
Medicare Dental Benefit Act of 2021, S 97-117th Cong (2021-2022). January 28, 2021.
,
Budget of the US Government for Fiscal Year 2022. Office of Management and Budget.
,
,
FY2022 Budget Resolution Agreement Framework.
State health facts: Medicaid benefits—dental services, Indiana 2010.
This loss of Medicaid dental service coverage was consistent with trends in other states and was likely related to the Great Recession.
Then in February 2015, Indiana Medicaid was expanded to accommodate adults whose incomes were from 100% through 138% of the FPT and included more options for dental coverage.
- Freedman S.
- Richardson L.
- Simon K.I.
This expansion initiative, called HIP 2.0, was built on the 2008 HIP program and offered 2 types of state Medicaid plans with varying dental service coverage. The first plan, HIP Basic, is available to adults up to 100% of the FPT and includes dental service coverage for accident or injury only. The second plan, HIP Plus, includes the option for more comprehensive dental coverage for enrollees at or below 138% of the FPT but requires that people make a monthly premium payment based on their income.
- Long S.K.
- Coughlin T.A.
- Ramos C.
- et al.
Dental services offered through HIP Plus are billed under managed care entities as fee-for-service claims. No modifications to reimbursement rates for low-income adult dental services were identified during this expansion period.
- Reynolds J.C.
- McKernan S.C.
- Damiano P.C.
- Kuthy R.A.
The findings of that study shed light on the relationship between Medicaid expansion and dentist participation in the state of Iowa; however, the study relied on data collected from a survey with a response rate of less than 50% among practicing dentists. A national study conducted in 2016 assessed the validity of different approaches to measuring Medicaid participation and found little correlation between the use of unadjusted workforce percentages and population-based per capita calculations to measure state-level Medicaid provider capacity.
Although this research is an important step in identifying the best strategy for measuring workforce capacity, these studies have largely relied on surveys in which participation in Medicaid is self-reported. The use of administrative data, such as Medicaid claims data, would be a more accurate estimation of providers’ Medicaid participation and capacity.
The primary objective of our study was to examine characteristics of Indiana dentists associated with Medicaid participation after expansion by applying an analysis framework that uses administrative Medicaid claims data.
Methods
Data sources and study dataset
Individual-level Medicaid provider data for fiscal years 2014 through 2017 were obtained through a data request submitted to the Indiana’s the Office of Medicaid Policy and Planning. This request was approved through a contract held between an Indiana state educational institution and the Indiana’s Department of Health. Medicaid provider data identified Indiana dentists by their unique license number and National Provider Identifier. These data also included the total number of dental claims rendered by year for each licensed Indiana dentist. No other data elements were included in the Medicaid provider data. A total of 1,847 dentists were included in the Medicaid claims data.
Dentists’ license and supplemental data elements collected during the 2018 license renewal period were obtained from the Indiana Professional Licensing Agency. The agency’s supplemental data elements included dentists’ reported demographics, education and training, and professional characteristics; these data elements were used as the source of covariates for this study. Dentists in the license and supplemental data were included in the study analysis if they held an Indiana state dental license that was consistently renewed from 2014 through 2018 and had complete data for variables that were included in this study. Dentists who reported their practice specialty as pediatric dentistry were excluded from the study analysis because Medicaid expansion under the Patient Protection and Affordable Care Act primarily focused on increasing coverage for low-income adults. Altogether, 144 dentists (around 4.6% of Indiana’s dentist workforce) were excluded from the analysis.
FigureInclusion criteria for study analysis.
Outcome variable
The outcome of interest in this study was dentist Medicaid participation status before and after Medicaid expansion. The outcome was analyzed as a 3-level nominal categorical variable. Dentists with no submitted claims during any year in the study period were classified as never active. Dentists who had no claims in 2014 but had claims each year from 2015 through 2017 were classified as active after expansion. Dentists having claims rendered for all years of the study period were classified as continuously active.
Covariates
Source: Dickinson and colleagues.39
Data management
Age was calculated using dentists’ date of birth and the date of the 2018 license renewal and classified as a 5-level categorical variable. Race was analyzed as a 2-class categorical variable (White and non-White) owing to the small number of dentists in the racial minority groups. Dentists’ specialty was derived from their self-reported practice type and residency status and was analyzed as a 3-class categorical variable owing to the small numbers in certain specialty groups. General dentistry included those who reported their practice type as general practice and those who reported public health in the instance that they did not complete a dental public health residency program. Oral and maxillofacial surgery was not reclassified, while other specialties included all remaining dental specialties.
Finally, this study analysis includes a measure of the potential increase in the population eligible for Medicaid coverage to determine if population characteristics affected dentists’ Medicaid participation. The percentage of the county population with an income level from 100% through 138% of the FPT was calculated using population income data taken from the US Census Bureau. This measure would represent potential increase in demand among Medicaid recipients in a dentist’s respective community.
Statistical analyses
Descriptive statistics were generated for the outcome variable and covariates. Frequency and percentages were calculated for each categorical measure. Means (standard deviations) were calculated for each continuous measure. A χ8 analysis was used to test for differences between categorical covariates and the outcome groups. Analysis of variance was used to test for differences in the mean population percentage newly eligible for Medicaid between the outcome groups.
Because the outcome was a 3-class nominal variable, a generalized multinomial logistic regression model was conducted. This statistical model allows for a calculation of the log odds of each outcome while adjusting for all predictors in the model. The adjusted odds ratios (OR) were calculated with the never active group as the reference. The logistic procedure with the glogit option was used in SAS 9.4 (SAS Institute) with statistical significance at α = 0.05.
Results
Descriptive analysis
Table 2Descriptive statistics for Indiana dentists, based on status of engagement in Medicaid during expansion (n = 2,037).
Multivariate logistics regression results
Table 3Likelihood of dentists becoming active in Medicaid after expansion or always being active in Medicaid [Reference Never Active].
Professionally, dentists who were in a group practice (OR, 2.573; P = .0001) were more likely to become active in Medicaid after expansion than those in a solo practice. The same was also true for dentists who had a practice in oral and maxillofacial surgery (OR, 5.894; P = .0002) compared with those in general dentistry. On the other hand, those dentists in dental practice specialties classified as other had a lower likelihood (OR, 0.166; P = .0001) of becoming active after expansion. Dentists who had a practice in oral and maxillofacial surgery (OR, 6.484; P < .0001), worked full time (OR, 1.259; P = .041), and had a practice located in a rural county (OR, 1.921; P < .0001) were also more likely to be continuously active in Medicaid during the study period. No statistically significant outcomes were found with regard to the percentage of the county population eligible for Medicaid after expansion.
Discussion
FY2022 Budget Resolution Agreement Framework.
, ,
State health facts: Medicaid benefits—dental services, Indiana 2010.
,
,
- Long S.K.
- Coughlin T.A.
- Ramos C.
- et al.
they also provide specific insight into participation after expansion. Moreover, this study used Medicaid claims and supplemental license data to examine dentists’ participation in the dental safety net. The framework used for this study, leveraging administrative and regulatory data sources that are available in many states, is more replicable than previously used methods.
- Guth M.
- Garfield R.
- Rudowitz R.
Previous studies have also found that Medicaid expansion has had a positive impact on oral health care use among Medicaid recipients.
- Wehby G.L.
- Lyu W.
- Shane D.M.
,
- Singhal A.
- Damiano P.
- Sabik L.
However, states with greater provider availability for low-income populations are more likely to see an increase in the number of dental visits during expansion.
- Wehby G.L.
- Lyu W.
- Shane D.M.
,
- Singhal A.
- Damiano P.
- Sabik L.
Thus, examining dentists’ participation in Medicaid is important for informing expansion and ensuring increased accessibility in communities in greatest need.
Additional research exploring dentists’ participation within states that have implemented other models of Medicaid expansion is needed to determine whether the findings of our study are unique to Indiana or generalizable across other types of expansion initiatives. In addition, the finding of increased postexpansion engagement in Medicaid among dentists without accompanying changes in reimbursement for dental services may suggest that reimbursement alone is not the sole incentive for participating in Medicaid. Future research is needed to provide insight into these findings.
Demographic characteristics
,
- Surdu S.
- Mertz E.
- Langelier M.
- Moore J.
,
Women are entering dentistry at an increasing rate and are more diverse than their male colleagues.
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- Mertz E.
- Langelier M.
- Moore J.
,
- McKay J.C.
- Quiñonez C.R.
Although few differences exist between male and female dentists in terms of practice patterns, female dentists are more likely to work part time, be employed instead of owning their practice, and provide more preventive care.
- Surdu S.
- Mertz E.
- Langelier M.
- Moore J.
,
- del Aguila M.A.
- Leggott P.J.
- Robertson P.B.
- Porterfield D.L.
- Felber G.D.
,
- Riley J.L.
- Gordan V.V.
- Rouisse K.M.
- et al.
These differences do not explain the findings of a relationship between Medicaid expansion and participation among female dentists but could have implications for the future of the dental Medicaid safety net. Additional research is needed to understand and contextualize this finding.
- Maxey H.L.
- Norwood C.W.
- Vaughn S.X.
- et al.
Dentists who identify as a racial or ethnic minority have previously been found to have a greater likelihood of accepting new Medicaid patients than their White counterparts.
- Okunseri C.
- Bajorunaite R.
- Abena A.
- Self K
- Iacopino AM
- Flores G
In addition, a study from Florida found that dentists who identified as Black or Hispanic were more likely to participate in Medicaid than any other racial or ethnic group.
- Logan H.L.
- Guo Y.
- Dodd V.J.
- Seleski CE
- Catalanotto F
The findings from this and another study support initiatives aimed at increasing diversity in the dentist workforce, especially when considering the significant contributions minority dentists make to the Medicaid dental safety net.
Professional characteristics
- Okunseri C.
- Bajorunaite R.
- Abena A.
- Self K
- Iacopino AM
- Flores G
,
In addition, the likelihood of accepting new Medicaid patients has historically been greater among dentists from larger practices than among those from smaller practices.
- Okunseri C.
- Bajorunaite R.
- Abena A.
- Self K
- Iacopino AM
- Flores G
Moreover, an increasing number of dentists are choosing to practice in group practice settings nationally and in Indiana.
,
,
- Vaughn S.
- Floyd T.
- Maxey H.L.
,
- Dickinson A.
- Vaughn S.
- Maxey H.L.
,
- Sheff Z.T.
- Nowak C.L.
- Maxey H.L.
,
- Vaughn S.
- Gano L.
- Maxey H.L.
If these trends continue, the growth of large group practices may enhance the availability and accessibility of dental services for Medicaid recipients.
- Maxey H.L.
- Norwood C.W.
- Vaughn S.X.
- et al.
This trend likely reflects the prevalence of dental diseases among low-income and Medicaid-insured populations that require access to more specialized oral health services, as well as dental services reimbursed under Medicaid.
,
Oral Health in America: A report of the Surgeon General.
,
- Eke P.I.
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,
- Edelstein B.L.
- Chinn C.H.
- Soni A.
- Hendryx M.
- Simon K.
Therefore, the finding of increased participation among dentists with practices in rural communities was not unexpected.
This study has notable limitations. First, this study includes dentists who may have only submitted 1 claim in a fiscal year, so the analysis is limited to absolute participation and provides no insight on level of participation. Second, data regarding dentists’ demographic and professional characteristics were derived from a voluntary self-reported survey administered as part of the biennial license renewal, introducing the potential of reporting bias. Also, because this study included only dentists actively practicing in Indiana, the generalizability of the results is limited. Finally, using the estimated percentage of the population potentially eligible for Medicaid also may have led to an overestimation of population demand.
Conclusions
Medicaid expansion has provided insurance coverage for more low-income people in the United States, thereby increasing the demand for health services. Our study has shown that certain characteristics of dentists are associated with participation in Medicaid after expansion and may affect dental care accessibility. As states consider expansion initiatives to cover additional populations or offer more comprehensive dental services, it is important to consider workforce characteristics associated with Medicaid participation to support and sustain the dental safety net.
Medicare Dental Benefit Act of 2021, HR 502-117th Cong (2021-2022). February 2, 2021.
,
Medicare Dental Benefit Act of 2021, S 97-117th Cong (2021-2022). January 28, 2021.
,
Budget of the US Government for Fiscal Year 2022. Office of Management and Budget.
,
,
FY2022 Budget Resolution Agreement Framework.
Dentist participation will be critical for the implementation of any reform initiatives. Dentists should seek opportunities to collaborate with policy makers at the state and federal levels on the creation or modification of policies related to dental services to ensure the voice of dentistry is heard and to identify barriers and develop collaborative strategies to increase dentist enrollment and engagement, which will ultimately enhance accessibility of dental services.
Strategies to Enhance Dentists’ Participation in Medicaid: A Review of Current Practices.
,
Nonfinancial Strategies to Increase Dentist Participation in Medicaid.
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Biography
Dr. Maxey is the director, Bowen Center for Health Workforce Research and Policy, Indiana University, Indianapolis, IN.
Dr. Vaughn is a health services research analyst, Bowen Center for Health Workforce Research and Policy, Indiana University, Indianapolis, IN.
Dr. Medlock is a health policy analyst, Bowen Center for Health Workforce Research and Policy, Indiana University, Indianapolis, IN.
Dr. Dickinson is a research coordinator, Bowen Center for Health Workforce Research and Policy, Indiana University, Indianapolis, IN.
Dr. Wang is a biostatistician, Department of Biostatistics and Health Data Science, Indiana University, Indianapolis, IN.
Article Info
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Published online: March 11, 2022
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DOI: https://doi.org/10.1016/j.adaj.2022.01.005
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