Recent Trends in the Utilization of Dental Care in the United States

Recent Trends in the Utilization of Dental Care in the United States Thomas P. Wall, M.A., M.B.A.; Marko Vujicic, Ph.D.; Kamyar Nasseh, Ph.D. Abstract: The authors examined trends in the utilization of oral health services in the United States from 1997 to 2010, including breakdowns by age and poverty level. They examined trends in one major driver of utilization: insurance coverage. The results suggest that the recent economic downturn did not result in an overall decrease in the utilization of dental services. Rather, the findings suggest an earlier decline from 2003 to 2008. In this article, the authors report that the overall trend masked significant variation by age and poverty level. Among children, there was steady growth in utilization from 1997 to 2010. This appears to have coincided with a shift away from private insurance toward public coverage and a significant drop in the percentage of uninsured children. Among non-elderly adults, however, utilization has been falling steadily since 1997 among all but the wealthiest income group. During the great recession from December 2007 to June 2009, the decline in utilization accelerated among those in the lowest income group. The decrease in adult utilization appears related to a decrease in private insurance coverage and an increase in public coverage and noninsured rates. As a consequence of these trends in coverage, the authors predict a continued decline in the utilization of dental services among non-elderly adults. Mr. Wall is Manager, Statistical Research, Health Policy Resources Center, American Dental Association; Dr. Vujicic is Managing Vice President, Health Policy Resources Center, American Dental Association; and Dr. Nasseh is Health Economist, Health Policy Resources Center, American Dental Association. Direct correspondence and requests for reprints to Mr. Thomas P. Wall, American Dental Association, 211 E. Chicago Ave., Chicago, IL 60611; 312-587-4126; [email protected]. Keywords: oral health, oral health services, oral health care access, dental insurance, economics

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lmost everyone experiences oral diseases and conditions over the course of a lifetime, but, unlike the common cold, most oral diseases do not resolve over time. Consequently, a pattern of regular dental visits complements self-care as a critical factor in achieving and maintaining good oral health. The utilization of dental services is also essential to promoting and maintaining overall health and well-being. Patients with regular dental visits are more likely to have oral diseases detected in the earlier stages and obtain restorative care as needed. Nonreceipt of dental services or a delay in receiving such services can result in delayed diagnosis, untreated oral diseases and conditions, compromised health status, and, occasionally, even death.1 The factors influencing dental care utilization have been well documented in previous studies.2-4 They include gender, age, education level, income level, race and ethnicity, geographic location, general health status, and dental insurance status. As many of these factors are closely tied to household economic conditions, it is expected that utilization of dental care would fluctuate, to some degree, with macroeconomic conditions. The United States is slowly emerging from the worst economic downturn since the great depression, and this situation is the starting point for the analysis reported in this article. Specifically, in our study we examined trends in the utilization of oral health services from 1997 to 2010, covering a period

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before, during, and after the recent economic recession. We examine utilization for different age groups and poverty levels where we have found interesting results to report. While our analysis is primarily descriptive, we examine trends in one major driver of utilization—dental insurance coverage—that warrants discussion and motivates further analytic work.

Methodology There are many ways to measure dental care utilization. Estimates are traditionally based on an individual’s reporting “at least one dental visit in the past year,” although there are variations with shorter recall intervals and different forms of the question.5 Other measures include the number of dental visits, total dental expenditure (as a proxy for volume of services), and indirect measures of whether “needed” care was received. We focus in this article on the simplest measure of utilization: a dental visit within the past year. Dental visit estimates for the overall U.S. population have been shown to vary across nationally representative surveys. However, a study documenting differences in overall estimates also reported that differences in oral health care utilization by gender, race/ethnicity, poverty status, and level of education are consistent across surveys.6 To study trends in the utilization of dental care, we used data from the National Health Interview

Journal of Dental Education ■ Volume 76, Number 8

Survey (NHIS). The NHIS is conducted annually and is the principal source of information on the health of the civilian, noninstitutionalized, household population of the United States. We relied on the NHIS because of the timeliness of the data. That is, we were able to include the 2010 NHIS in our analysis. The NHIS also has a larger sample size than other surveys, which results in more reliable estimates for small population groups. The Family Core component of the NHIS collects information on every member of a sample household, including information on demographics and insurance coverage. One adult and one child per household are randomly selected for the Sample Adult Core and Sample Child Core components. In 2010, the final response rate for the Sample Adult component was 60.8 percent, and the final response rate for the Sample Child component was 70.7 percent.7

Dental Visit During the Past Year The Adult and Child Sample components include a question about the length of time since the last dental visit: “About how long has it been since {sample person} last saw a dentist? Include all type of dentists, such as orthodontists, oral surgeons, and other dental specialists, as well as dental hygienists.” Respondents who indicated “six months or less” or “more than six months, but not more than one year ago” were considered to have had a dental visit during the past year. In recent years of the NHIS, information about a dental visit is collected about children as young as one year of age. However, because the lowest age limit was two years for earlier years of the NHIS, we used two years of age as the lower limit for all years of the NHIS included in the analysis.

Insurance Categories and Poverty Levels Children and non-elderly adult respondents were assigned to one of three insurance coverage categories based on coverage at the time of the interview. Respondents were considered covered by private health insurance if they indicated private health insurance or if they were covered by a singleservice hospital plan, except in 1997 and 1998, when no information on single-service plans was obtained. Persons were considered to be covered by Medicaid if they reported Medicaid or a state-sponsored health

August 2012 ■ Journal of Dental Education

program. Starting in 1998, persons also were considered to be covered by Medicaid if they reported being covered by the Children’s Health Insurance Program (CHIP). Persons without coverage were identified using the variable NOTCOV, which reflects the definition of noncoverage used in Health, United States, 2010 (in which persons with only Indian Health Service coverage are considered uninsured).8 A small percentage of respondents were considered to have unknown coverage. Most years of the NHIS do not include questions regarding dental insurance. However, the 2008 NHIS asked those under sixty-five years of age with private health insurance about coverage for dental services. A National Center for Health Statistics Data Brief based on the 2008 NHIS reported that 73 percent had some type of dental coverage.9 Income is expressed in terms of poverty status, the ratio of the family’s income to the Federal Poverty Level thresholds, which control for the size of the family, and the age of the head of the family. Household poverty level for households in the sample with unknown values for income, household size, or both was calculated using single imputation methods. The poverty level estimates and confidence intervals based on single imputed poverty level may differ slightly from those obtained using multiple imputation methods. All estimates and tests of significance accounted for the complex design of the survey.

Results Note that all differences discussed in this section were found to be statistically significant, except where otherwise noted. Ninety-five percent confidence intervals were constructed for each estimate. When looking at changes over time, differences between estimates were judged to be statistically significant if the confidence intervals did not overlap. Table 1 shows the trend in the percentage of the U.S. population with a dental visit during the past year for the years 1997 to 2010. The changes from year to year appear to be relatively small. However, small percentage point changes in the utilization rate can represent a large number of people who visit a dentist. For example, in 2010, a change of two percentage points corresponds to about 6 million people. Three changes of approximately this magnitude can be seen in Table 1. The first was a decrease from 66.4 percent in 2000 to 64.7 percent in 2002. The second was an increase from 64.7 percent in 2002

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to 66.4 percent in 2003. These changes correspond roughly to the recession in 2001 and subsequent recovery. The third significant change was a decrease from 66.4 percent in 2003 to 63.9 percent in 2008. 2008 was the first full year of the great recession,

Table 1. Percentage of U.S. population with a dental visit during the past year, 1997 to 2010 Year

Percentage with a Dental Visit

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

95% confidence interval

65.1% 64.5–65.7 66.3% 65.7–67.0 65.1% 64.4–65.7 66.4% 65.7–67.0 65.7% 65.0–66.4 64.7% 64.0–65.4 66.4% 65.7–67.0 66.0% 65.4–66.6 65.8% 65.1–66.5 64.9% 64.1–65.7 65.3% 64.5–66.1 63.9% 63.0–64.9 65.4% 64.6–66.1 64.7% 63.9–65.5

Source: National Health Interview Survey.

which began in December 2007 and ended in June 2009. However, the decline in utilization began five years earlier. Figure 1 shows how the trend in utilization from 1997 to 2010 varied by patient age. Three broad age groups are shown: children two to twenty years of age, non-elderly adults twenty-one to sixty-four years of age, and the elderly who are sixty-five years and older. According to the 2010 NHIS, these age groups accounted for 25.8, 58.6, and 12.7 percent of the population, respectively. There were remarkable differences in the utilization patterns for these three groups. The utilization rate for children two to twenty years of age shows a steady increase, from 71.6 percent in 1997 to 77.0 percent in 2010. The utilization rate for non-elderly adults shows a steady decrease from 66.8 percent in 2000 to 61.8 percent in 2010. The utilization rate for the elderly decreased from 73.1 percent in 1997 to 69.6 percent in 2010, but was steady from 2000 to 2007. Figure 2 shows trends in utilization for children ages two to twenty years by poverty level. Relatively large increases between 1997 and 2010 were reported for children in the two lowest income groups. The

74.4% 71.8% 66.4%


Figure 1. Percentage of U.S. dentate population with a dental visit during the past year by patient age, 1997, 2000, 2003, 2007, 2010

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increases for children in the two highest income categories were not found to be statistically significant. The gap between the levels of utilization among those in the lowest income group and those in the highest income group fell by about one quarter, from 22.1 percentage points in 1997 to 16.3 percentage points in 2010. Figure 3 shows recent trends in utilization among non-elderly adults. Between 1997 and 2010, the level of utilization fell in all but the highest income category where it remained relatively stable. Further, from 2007 to 2010, there was a five percentage point drop in utilization among non-elderly adults in the lowest income category—a remarkable reduction over a three-year period. We do not attempt here to fully analyze the underlying drivers of the observed trends in utilization. This is left to subsequent work. However, given the importance of insurance coverage as a driver of dental care utilization, we highlight some important findings. As shown in Figure 4, the percentage of children covered by private insurance fell from 66.2 percent in 1997 to 54.2 percent in 2010. During the same period of time, the percentage of children covered by public insurance (Medicaid/CHIP) increased

< 100% FPL

100-199% FPL

from 16.1 to 32.2 percent. The percentage without insurance declined from 14.4 percent in 2000 to 10.2 percent in 2010. The decline in the percentage of children who are uninsured is certainly likely to be one important factor explaining the increase in dental utilization among children since 1997. As shown in Figure 5, the percentage of nonelderly adults covered by private insurance fell from 74.0 percent in 1997 to 65.8 percent in 2010. During the same time period, the percentage covered by public programs (Medicaid) increased from 5.4 to 8.3 percent. However, the percentage without insurance increased from 17.8 percent in 1997 to 21.1 percent in 2010. The increase in the percentage of adults who were uninsured or covered by Medicaid (where dental coverage is very limited) is likely to be one important factor explaining the decrease in dental utilization among non-elderly adults since 1997. Taken together, these results indicate that there have been major gains in the utilization rate of dental care among poor children since 2007, to the point that the utilization gap between poor and non-poor children was reduced considerably. Further, the economic turndown appears to have had little impact on the upward trend in utilization among poor

200-399% FPL

400%+ FPL


Figure 2. Percentage of U.S. children aged two to twenty with a dental visit during the past year by poverty level, 1997, 2000, 2003, 2007, 2010


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< 100% FPL

100-199% FPL

200-399% FPL

400%+ FPL


Figure 3. Percentage of U.S. dentate adults aged twenty-one to sixty-four with a dental visit by poverty level, 1997, 2000, 2003, 2007, 2010

children. For adults, there were considerable declines in the utilization rate among all except the wealthiest income group. Further, among those in the lowest income category, the downward trend in utilization accelerated during the economic downturn. This study had some limitations. First, we based our analysis of the utilization of dental services on the percentage with a dental visit during the past year. Other measures such as dental visit frequency and expenditures may be better measures of intensity of treatment. Second, our measure of the utilization of dental services relied on self-reported data, which can result in measurement error. Third, in our study, private health insurance was considered as a proxy measure of private dental insurance. Fourth, public health insurance (Medicaid/CHIP) is an imperfect proxy measure of public dental insurance for adults because states are not required to cover dental services for Medicaid adults. In 2010, twenty-two states offered no dental benefits for Medicaid adults or limited those benefits to emergency services.10 As our primary interest is analyzing trends over time rather than absolute levels, we feel the analysis provides significant insights despite the limitations.

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Discussion We found that the recent economic downturn did not result in a statistically significant decline in the utilization rate for dental care among the population as a whole. Rather, we found something more surprising: a fairly steady decline in aggregate utilization from 2003 to 2008. More importantly, however, we found that the aggregate trend masks significant variation by age and poverty level. Among children, there has been a steady increase in utilization from 1997 to 2010. This appears to have coincided with a shift away from private insurance toward public insurance and a significant drop in the percentage of children who are uninsured. The authors of a recent annual report on Medicaid and CHIP point out that, in 2010, in spite of the country’s continuing economic problems, nearly all states “held steady” in terms of playing a central role in providing coverage to millions of people who would otherwise lack affordable coverage options.11 Those authors attribute the stability in public programs to the government’s decision both to provide temporary Medicaid fiscal relief to states through



Figure 4. Percentage of U.S. children under twenty-one years of age covered by various types of health insurance, 1997, 2000, 2003, 2007, 2010


Figure 5. Percentage of non-elderly adults covered by various types of health insurance, 1997, 2000, 2003, 2007, 2010


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June 2011 and to require states to maintain their Medicaid and CHIP eligibility rules and enrollment procedures until broader health reform goes into effect. This explains the substantial increases in Medicaid dental spending in recent years. From 1997 to 2010, Medicaid and CHIP dental expenditures increased from $2.0 billion to $8.5 billion, or 9.3 percent per year in inflation-adjusted dollars.12 This was a much faster growth rate than private dental spending, which increased at 2.9 percent in inflation-adjusted dollars during the same period. The continued growth in utilization during the great recession among the poorest children was notable because the number of children in this income category grew by almost 3 million, from 14.5 million in 2007 to 17.4 million in 2010. Supported by significant increases in funding, the dental safety net for children appears to be holding up. A recent report from the Centers for Medicare & Medicaid Services documents the clear record of improved children’s access to dental care in Medicaid/CHIP, but the authors point out that the national numbers mask considerable variation in performance among states.13 In contrast to the findings for children, we found that the story regarding non-elderly adults was very different. Utilization has been falling steadily since 1997 among not just the poor but among all but the wealthiest income group. Further, during the great recession, the decline in utilization accelerated among those in the lowest income group. Combined with the fact that the number of adults in the lowest income groups grew by 4 million from 2007 to 2010, this clearly indicates that the number of non-elderly adults who have forgone or delayed dental care has increased dramatically. Similar to children, the decrease in adult utilization appears to have corresponded with a decrease in private insurance coverage and a corresponding increase in public insurance coverage. However, unlike among children, the share of non-elderly adults who are uninsured increased. As more adults have fallen into the uninsured and Medicaid-insured categories, it is not surprising that utilization rates have fallen. Historically, the dental safety net has not been as strong for adults as for children. Dental services for adults are not a mandated benefit under Medicaid. In 2010, twentytwo states offered no dental benefits for Medicaid adults or limited those benefits to emergency services.10 Many other states place limits on the type and amount of dental services that are covered. For example, services may be limited to one examination

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and cleaning per year, or a cap may be placed on the dollar amount of services that will be covered in a given year. It is also important to note that most states set income limits for Medicaid eligibility at a much lower level than for children. The dental safety net for adults thus appears to be failing. Our results are consistent with a recent study that found that access to and use of health services, including dental care, among non-elderly adults deteriorated between 2000 and 2010.14 According to that study, the most dramatic declines occurred among the uninsured. Over the decade, this group became more likely to forgo or delay getting needed care and less likely to have a usual source of care and to have had a visit with a doctor or dentist. Although the most dramatic declines occurred among the uninsured, access declined for adults in every insurance coverage category. Again, we emphasize that our analysis is based on a very basic measure of utilization of dental care. We in no way shed light on any potential changes to the type of dental care received, whether “needed” care is being delivered and ultimately whether oral health outcomes are improving. This is left for future study. We also stress that we only reviewed trends in insurance coverage and did not examine the drivers of utilization more broadly. Other factors need to be accounted for including demographic shifts in the population, potential improvements in oral health, shifts in household income, etc. What might happen in the near future? Fiscal, economic, and demographic forces are colliding to produce significant forces that could reshape utilization patterns in years to come. Under the Affordable Care Act (ACA), more children will be covered for dental services under public programs, but the ACA is not expected to expand dental coverage for adults.14,15 At the same time, states are facing continued fiscal pressures and are looking for ways to reduce their spending. In regards to private dental coverage, the percentage of companies offering health insurance that also offer dental insurance has remained stable for several years.16 However, fewer employers are offering health benefits. According to a recent report, the percentage of employers offering health benefits fell from 69.2 percent in 2000 to 58.6 percent in 2010.17 Dental benefits are falling at the same rate. As a consequence of these trends, the coming years could bring a continued decline in the utilization of dental care among non-elderly adults that could have serious effects on the oral health of the public.


REFERENCES

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