Improving Access and Quality
Research in Action, Issue 13
Dental care research funded by the Agency for Healthcare Research and Quality (AHRQ) looks at the impact of a wide variety of factors. These include the impact of reimbursement, race, income, and age on access to and use of dental care.
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Background / Access to Adequate Care / Measuring the Quality of Dental Care / Ongoing Research and Programs / Conclusion / AHRQ-Funded Research / References
By Mark W. Stanton, M.A.
Background
The oral health of Americans has improved in recent years,
yet considerable gaps in the provision of dental care
remain, according to a recent report by the Surgeon
General.1
This Research in Action highlights dental care research
sponsored by the Agency for Healthcare Research and
Quality (AHRQ). Studies look at the impact of factors such
as reimbursement, race, income, and age on access to and
use of care.
Research suggests that educating families about
how to enroll in and access the Medicaid system,
streamlining Medicaid administrative procedures, and
adjusting provider reimbursement could facilitate broader
access to dental care. Studies show that specific treatments
such as dental sealants for children may have a positive
impact on both health outcomes and costs. The quality of
dental care can be further improved by developing and
using performance measures for specific treatments.
Finally, the production of evidence reports evaluating
research on various aspects of care helps to advance
evidence-based dental practice and thereby improve the
quality of care.
The Surgeon General's recent report states that oral health
is essential to the general health and well-being of all
Americans.1 Although oral health extends beyond dental
health, the report clearly stresses the importance of the two
leading types of dental disease:
- Tooth decay (dental caries).
- Periodontal disease.
Dental care can be either preventive or restorative.
Preventive care, such as tooth cleaning and dental sealants,
is aimed at avoiding dental problems. Restorative care repairs problems such as those caused by tooth decay and
periodontal disease.
Oral Health Improves Overall but Gaps Exist
Over the past several decades, oral health in the United
States has improved.a Among most age groups, the average
number of teeth per person affected by dental caries has
decreased. Also, the average number of teeth per person
that show no signs of infection, as well as the proportion of
the population that is caries free, has increased. In addition,
a lower proportion of U.S. adults have lost all their natural
teeth (a process associated with both tooth decay and
periodontal disease) now than was the case two decades
ago. This improvement is most pronounced at older ages.
Despite the overall improvement in oral health status, gaps
in the provision of care remain. Over the 20-year period
1977-96, the gap in the use of services between low-income
people (those with incomes under 200 percent of the
Federal poverty level) and higher income people (those
with incomes over 400 percent of the Federal poverty level)
increased.2 The number of preventive visits is below
recommended levels, and access to dental care remains
problematic for minorities, the elderly, children on
Medicaid, and other low-income children. For example:
- More than one third (36.8 percent) of poor children ages
2 to 9 have one or more untreated decayed primary
teeth, compared to 17.3 percent of nonpoor children.
- Uninsured children are half as likely as insured children
to receive dental care.3
- Untreated dental decay afflicts one-fourth of children
entering kindergarten in the United States.
- Low-income and minority children have more dental
cavities than other children.
- Poor Mexican-American children ages 2 to 9 have the
highest proportion of untreated decayed teeth (70.5
percent), followed by poor non-Hispanic black children
(67.4 percent).
- Poor Mexican-American and non-Hispanic black
children see the dentist less often than other children.
- Less than one of every five poor children enrolled in
Medicaid receives preventive dental services in a given
year, even though Medicaid provides dental coverage for
enrolled children.
In addition to the considerable access problems faced by
poor and Medicaid-eligible children, poor elderly people
and minorities have their own problems with access.
- In the 50-69 age group, non-Hispanic blacks (31.2
percent) are more likely than Mexican Americans (28.2
percent) or non-Hispanic whites (16.9 percent) to have
at least one tooth site with periodontal disease.
- In the age category 70 years and over, the percentages
rise to 47.1 percent, 32.0 percent, and 24.1 percent for
the three groups.
With more elderly people having discretionary income and
retaining their natural teeth, demand for dental services
among the elderly has grown. But this demand can be
substantially influenced by financial barriers and other
health concerns. Studies show that the elderly typically
underuse needed dental services.
The underuse of cost-effective preventive services such as
dental sealants, plastic coating applied to protect the
chewing surface of teeth, also illustrates that dental care in
the United States has room for improvement.
a. Unless otherwise referenced, the information in this section comes from
the Surgeon General's report.
Performance Measurement Is in its Early Stages
Beyond the issues of access and underuse, there is the
question of how to measure the quality of care that is
delivered. The ability to measure the quality of dental care
is a key to improving it, but most plans do not collect data
to produce standardized measures. Once the process of
performance measurement is underway, it will be possible
to identify specific treatment areas where improvements
can be made. For example, some research has shown that
the treatment of dental patients with previous restorations
(different repairs to teeth, such as fillings, crowns, and
bridges, that restore original function) has a relatively high
degree of variability, which may or may not be related to
patient-specific factors. Further research may be able to
show which type of restoration is most effective.
Measuring performance becomes more feasible when
evidence reports are available that systematically evaluate
the efficacy of techniques for the diagnosis, prevention, and
treatment of dental caries and other dental diseases.
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Access to Adequate Care
AHRQ-funded studies have identified disparities in the
dental care used by poor children and elderly blacks. These
studies have shown that, despite Federal requirements,
children who are enrolled in the Medicaid program or are
among the near-poor receive less dental care than is
recommended for their age group. For example, they are
less likely to receive regular preventive visits than those in
higher income groups. Also, they are less likely to have
their teeth treated with dental sealants (plastic coating on
the chewing surfaces of teeth), a treatment shown to
improve outcomes and lower overall treatment costs. Poor
elderly minority people also may not receive needed dental
care. The reasons for these disparities are varied, but they
include financial barriers to care, unavailability of dentists
in poor neighborhoods, administrative complexities in
qualifying for Medicaid eligibility and treatment approval,
and insufficient participation by dentists in the Medicaid
program.
Low-Income Children Have Unmet Dental Needs
An AHRQ-supported study analyzing data from the 1996
Medical Expenditure Panel Survey (MEPS)b on use of
preventive dental care by 6,595 children and adolescents
found that poor children have significantly fewer preventive
dental visits than those with higher incomes.4 Poor and
near-poor children age 18 and under were only about half
as likely to have had preventive dental visits as children in
middle or high income brackets across racial/ethnic groups
(Figure 1).c For example, 16 percent of poor black children
and 12 percent of near-poor black children had preventive
visits, compared with 26 percent of those with middle or
high income.
The same study also analyzed Maryland-specific data from
the Centers for Medicare & Medicaid Services and found
that only 31 percent of Medicaid-insured children had
received preventive care during 1996. This proportion was
unexpectedly low, given that States are required by Federal
law to provide dental care to all Medicaid-eligible children
from birth to 21 years of age. The required coverage
includes annual dental exams, prophylaxis and fluoride
treatments, and other emergency, preventive, and restorative
services, such as fillings and oral surgery.4
The situation for Medicaid children in Georgia and
Alabama is comparable to the situation in Maryland,
according to a study by the Children's Health Insurance
Research Initiative (CHIRI™),d funded by AHRQ, The
David and Lucile Packard Foundation, and the Health
Resources and Services Administration.5 Less than a third
of Georgia Medicaid children (30 percent) received dental
care in 1997, and less than a quarter of Alabama Medicaid
children (18 percent) received dental care in 1999. Almost
all of the children who had any dental care received
preventive care, with approximately half receiving acute
dental services such as emergency or restorative care.
Another AHRQ-funded study reported that half of 1,297
Medicaid-enrolled schoolchildren in North Carolina never
used dental services. Among children who got care, 45
percent needed restorations in primary teeth and 25 percent
needed restorations in permanent teeth. Among these
children, 29 percent had all their dental needs met, 28
percent had their needs partially met, and 43 percent had no
dental needs met.6
b. MEPS is the third in a series of medical expenditure surveys conducted
by AHRQ. It is a nationally representative survey that collects detailed
information on the health status, access to care, health care use and
expenses, and health insurance coverage of the civilian
noninstitutionalized population of the United States.
c. In 1996, the Federal poverty line was approximately $16,500 for a
family of four. The near-poor are those between 101 and 200 percent of
the Federal poverty line.
d. The CHIRI™ study is based on claims data from Alabama (1999) and
Georgia (1997); therefore, its findings cannot be directly compared to the
earlier study based on 1996-97 survey data from MEPS.
Dental Sealants for Medicaid Children Are Underused
Even when poor and near-poor children have access to a
dentist, they may not receive generally accepted
recommended care such as dental sealants. Dental sealants
prevent tooth decay, save money, and are an important
preventive measure, complementing the use of fluorides.
They work by preventing decay from developing in the pits
and fissures of teeth, channels that are often inaccessible to
brushing and where fluoride may be less effective. All
States now include sealants as a dental benefit for children
enrolled in their Medicaid dental programs; however, dental
sealants are underused.
An AHRQ-funded study that examined the dental
experiences of 15,438 children enrolled in the North
Carolina Medicaid program from 1985 to 1992 found that
sealants were effective in preventing tooth decay in the
chewing (occlusal) surfaces of the bicuspid and molar
teeth.7 This reduced the need for CRSOs (caries-related
services involving the occlusal surfaces of these teeth). The
most effective use of sealants was among children who had
more dental services for cavities before sealant placement.
Furthermore, researchers found that restoration rates (cavity
fillings) for high-risk children peaked at 8 years for
unsealed teeth and at 9 years for sealed teeth (18 vs. 8
percent). The effects of sealants are greatest when the child
is roughly 8 years old; after that age, sealant effectiveness
declines.
The Medicaid program saved money by using sealants for
children prone to cavities. The greatest difference between
expenses for sealed and unsealed teeth ($15.21 per molar)
occurred among the high-risk patients at age 9. These
savings were realized within a 2-year period following
sealant application among children with two or more prior
CRSOs.
However, AHRQ research has documented that, in spite of
the savings realized from their use, these treatments are
underused in the Medicaid program.6 For example, among
219 North Carolina children enrolled in Medicaid who
needed sealants for 615 teeth, only 21 teeth (3 percent)
were sealed, 195 (32 percent) received fillings, 23 (4
percent) were extracted, and 376 (61 percent) received no
treatment within a 2-year followup period.
Poor Elderly African Americans May Lack Access
The Surgeon General's report found that people 55 to 74
years of age have higher rates of periodontal disease and
also have an increasing amount of tooth decay compared to
younger adults. The elderly's use of dental care can be
substantially influenced by financial barriers and other
nondental health concerns.
AHRQ-supported researchers
analyzed dental and medical claims data from 1983 to 1992
for 3,458 individuals age 62 years and over who visited two
urban health care facilities and participated in a special
Medicare-waiver program that reimbursed for dental
services (not usually covered by Medicare).8 They
compared age, race, medical use, and pharmaceutical use
among people who used both medical and dental services
(dental users) and those who used only medical services
(nondental medical users).
Researchers found that among poor, elderly city residents,
blacks were twice as likely as whites to use dental services
that are reimbursed by a Medicare waiver program.
Eliminating financial barriers among less affluent and less
educated minority elderly people has a definite effect on
their use of oral health care services.
In addition, nondental medical users had twice as many
medical visits each month and more than twice the monthly
medical charges in the program as dental users had (.99
visit vs. .56 visit per month and $43 vs. $21 in charges per
month). Dental users were more likely to be younger (born
after 1910) and black (63 percent vs. 36 percent white) than
nondental users, with twice as many blacks as whites
participating in the dental waiver program.
The decrease in oral health care services associated with
increased use of medical services seems to indicate that as
health declines, people are less inclined or able to seek
dental care. This could indicate a decrease in the priority
given to oral health care, decreased ability to access oral
health care services, or both. The researchers suggested that
African Americans in the study were more likely to use
dental services because their access to services improved.
The absence of private-sector dentists in their own
communities was mitigated by the availability of a city-run
facility providing dental services under a special Medicare-waiver
program that reimbursed for dental services.8
Access to Medicaid Dental Care May Be Improved
AHRQ-supported researchers have offered their own
suggestions about how to improve access to Medicaid
dental care. Their suggestions focused on two areas:
- Education.
- Administrative simplification.
For example,
the research team that studied the impact of income on the
use of preventive care suggested that poor and near-poor
families may not know how to use available resources
effectively. They concluded that educating families eligible
for Medicaid and State Children's Health Insurance
Program (SCHIP) programs about how to enroll and access
the system may be essential for the success of these
programs.4
Another group of researchers who studied schoolchildren
and Medicaid suggested that streamlining Medicaid
administrative procedures (e.g., Medicaid eligibility,
treatment approval) could also contribute to better care. For
example, instituting a mechanism for prior approval of care
once a child appears for his or her first dental visit would
help to ensure that all needed care could be completed
quickly and without the need for further approvals.6
One factor contributing to insufficient dental care may be
that dentist participation rates in Medicaid remain low. The
CHIRI™ study5 found that children were more likely to
receive restorative dental care if they lived in counties
where there was a greater than average number of
Medicaid-participating dentists per enrollee.
The dentist participation rates are themselves partly a
function of the reimbursement levels provided under the
Medicaid program. One AHRQ-funded study examined
what happened to participation when reimbursement rates
were increased.9 The study found that increasing provider
reimbursement by 23 percent, even when accompanied by a
doubling of enrollment for individuals under age 21, had
only marginal effects on increasing access to dental
services for the Medicaid population. From 1985 to 1991,
Medicaid enrollment doubled in North Carolina; during the
final 4 years of the study (1988-91) there was a 23-percent
increase in Medicaid reimbursement to dentists. However,
following the implementation of these two measures, the
percentage of dentists seeing 5 or more Medicaid-insured
children per quarter remained fairly constant and the
percentage seeing 10 or more such children per quarter
increased only slightly.
Among providers seeing at least 10 Medicaid children per
quarter, an increase in real Medicaid reimbursement from
$13 to $14 yielded an expected 3 percent (.83 person)
increase in the number of Medicaid children seen per
quarter. Pediatric dentists were significantly more likely to
participate in Medicaid than general dentists (probability of
.58 vs. .20). Pediatric dentists also saw more than 2.5 times
as many Medicaid children per quarter as general dentists
did. Dentists in solo versus group practices were more
likely to participate in Medicaid, and dentists with more
years of experience were less likely to participate.
The researchers who conducted the North Carolina study
did not conclude that increased reimbursement had little or
no effect on dentist participation. Instead, they concluded
that greater participation may require much larger increases
in reimbursement.9
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Measuring the Quality of Dental Care
An important focus of performance measurement to
improve quality of care is the study of variations in the use
of dental procedures. These variations (by geographic area,
practice type, etc.) suggest the possibilities of overuse and
underuse. Similar concerns are found in medical care. For
example, health services research has examined variations
in the provision of medical care for patients with similar
medical conditions living in different geographic areas. It
has also studied patterns of possible overuse and underuse
of medical procedures.10-12 These studies in turn have raised
questions about the extent to which patient-specific factors,
provider preferences, and practice styles influence treatment
decisions.
Unexplained Variations in Clinical Decisions Are
Widespread
Are documented variations in the provision of dental
treatments simply reflections of the art of dentistry or are
they caused by uncertainty or disagreement about which
treatment is the most effective? Because quality-of-care
measures for evaluating the performance of oral health
insurance plans have not been available, these questions
have not yet been answered and the quality of care
furnished cannot be systematically evaluated.
In a comprehensive review of the literature regarding
variation in dentists' clinical treatment decisions, AHRQ-funded
researchers found substantial variation in areas such
as the rate of provision of specific procedures, the cost and
number of procedures recommended for specific patients,
diagnoses, intervention decisions, and treatment selection
for individual teeth.13
For example, in one study that
compared six capitated practices with five fee-for-service
practices, average rates of restorative services were higher
in the fee-for-service practices: three times as high for
adults and four times as high for children. In another study,
the proposed treatment costs for two patients examined by
15 North Carolina dentists ranged from $180 to $1,340 for
one patient and $420 to $2,400 for the other.13
From their review of the literature, the researchers
concluded that even when differences in patients are
accounted for, variations in dentists' clinical decisions are
widespread. Such variations, which raise questions about
possible overuse and underuse of care, definitely need to be
better understood.13 The studies discussed below have
begun to lay the foundations of evidence-based
performance measurement for dental care.
Cost-Effectiveness of Different Restorative Treatments
Is Unknown
Further studies examine restorative treatment recommendations and the effects
of the choice of treatment on the cost of care. One study examined the extent
to which dentists agreed about the treatment of 1,187 teeth in 43 patients.14
Each patient was examined by an average of 6.6 dentists, with a total of 51
participating dentists. Overall, agreement among the participating dentists
in recommending individual teeth for treatment was 62 percent. Among all teeth
receiving at least one recommendation for treatment, only 22 percent received
a unanimous recommendation. However, over half of all instances of lack of agreement
occurred when one dentist's recommendation differed from those of all the other
dentists examining the tooth. The results suggested that much of the variation
stemmed from basic differences in recommended treatment for individual teeth
with specific conditions. In cases where a tooth had been previously restored,
differences in treatment recommendations tended to be greater. The researchers
conclude that their study shows the need to develop objective criteria for treatment
of teeth with previous restorations.14
Another study by the same researchers explored the effects
of variation in both dentists' decisions to treat and choices
of restorative treatment on the cost of care.15 The patients
selected for the study needed decisions about a variety of
single-tooth restorations and had no substantial periodontal
complications. Three types of restorations—amalgam
fillings, composite fillings, and crowns—varying widely in
cost were considered.e Thirty-seven patients were
examined individually by several practicing dentists. For
each dentist's recommended treatment for each patient, the
total cost of restorative treatment was calculated first by
using the least expensive treatment possible for each tooth
designated as needing treatment and second by using the
treatment selected by the dentist. The average cost per
patient of the treatment selected ($893) was three times
larger than the cost per patient of basic treatment ($269).
Most dentists did not consistently recommend either higher
or lower cost treatment plans.
The findings suggest that inconsistencies in both dentists'
decisions to perform restorations and their selection of
treatment have a profound effect on costs. However, the
researchers caution that since there is a relative lack of
information about the cost-effectiveness of low- and high-cost
treatment alternatives, appropriate treatment planning
and rational cost containment are very difficult. The
researchers suggest that comprehensive efforts to improve
consistency across the profession would be more productive
than focusing on "outlier" dentists who choose more high-cost
treatments.15
e. Amalgam fillings are made from a silver/mercury mixture. Composite
fillings contain a mixture of filler particles such as silica, aluminum,
zinc, tin, copper, and iron in a liquid resin. A crown is full coverage for a
tooth (used when the tooth cannot be restored by a filling). Crowns are
much more expensive than either the amalgam or composite fillings.
Most dental schools teach that a crown is the preferred treatment for
substantially compromised posterior teeth with extensive caries,
fractures, or large defective restorations (fillings), as opposed to a direct
metal alloy (amalgam) or composite resin filling.
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