Cost-Effectiveness Model for
the Prevention of Early Childhood Caries

Francisco J. Ramos-Gomez, DDS, MSc, MPH, and Donald S. Shepard, Ph.D.

Copyright 1999 Journal of the California Dental Association.

This study presents and illustrates a model that determines the cost-effectiveness of three successively more complete levels of preventive intervention (minimal, intermediate, and comprehensive) in treating dental caries in disadvantaged children up to 6 years of age. Using existing data on the costs of early childhood caries (ECC), the authors estimated the probable cost-effectiveness of each of the three preventive intervention levels by comparing treatment costs to prevention costs as applied to a typical low-income California child for 5 years. They found that, in general, prevention becomes cost-saving if at least 59 percent of carious lesions receive restorative treatment. Assuming an average restoration cost of $112 per surface, the model predicts cost savings of $66 to $73 in preventing a one-surface carious lesion. Thus, all three levels of preventive intervention should be relatively cost-effective. Comprehensive intervention would provide the greatest oral health benefit; however, because more children would receive reparative care, overall program costs would rise even as per-child treatment costs decline.

Most children seeking emergency treatment are affected by early childhood caries (ECC), also known as baby bottle tooth decay or nursing caries. ECC is a complex, multifactorial disease causing severe decay of primary teeth. ECC poses a serious threat to child welfare, particularly among young disadvantaged children. The overall prevalence of ECC varies from 5 percent to 72 percent, depending on diagnostic criteria, age, race, and population. ECC can manifest itself in severe pain, infection, abscesses, or chewing difficulty and can lead to malnutrition, gastrointestinal disorders, and low self-esteem. Decay of primary teeth can affect children’s growth, lead to malocclusion by adversely affecting the correct guidance of the permanent dentition, and cause poor speech articulation. Studies have also shown that ECC may be associated with the future decay of the permanent dentition. ECC patients generally cannot be managed in the dental chair and, therefore, need anesthesia for treatment. All of these factors make this disease very expensive to treat, and many of the parents of these patients cannot afford to follow their dentist’s recommendations. The population most in need of medical and dental care for ECC does not receive it because of the scarcity of funds, lack of insurance to pay for regular preventive dental visits, and difficulty in gaining access to dental providers.

If diagnosed early, ECC is preventable. To stem the incidence of this infectious disease, the American Academy of Pediatric Dentistry and the American Academy of Pediatrics recommend that children have their first dental visit by their first birthday. The academies recommend this proactive, preventive approach to counsel parents about the need for preventive dental care and to explain the expected milestones in dental development, as highlighted in the Anticipatory Care Guidance for Children’s Dental Health.¹ Counseling visits for parents should cover topics such as oral development, fluoride intake, oral health and hygiene, eating habits, and the prevention of injuries. Preventive treatment provided prenatally for mothers is also an important element in inhibiting caries development in children. Early childhood dental visits combined with appropriate prenatal care for mothers may help to prevent or delay the formation of early childhood caries. Effective anticipatory care guidance consists of appropriate risk assessment and monitoring for children combined with parental counseling visits.

ECC is a preventable disease that unnecessarily affects the most vulnerable population. However, general dental practitioners can make a significant contribution to preventing this illness by welcoming young children into their practices. The protocols for preventing this disease are easily understood and implemented, and they can be readily integrated into general practices. Anticipatory care guidance measures provide dentists with an opportunity to help parents enhance the oral health of their children; at the same time, the dentist can reinforce positive oral health behaviors among all family members.

Background

Prevalence

Low estimates of the prevalence of caries among disadvantaged children age 3 to 5 years range up to 15 percent in fluoridated communities and up to 20 percent in nonfluoridated communities.^2,3 A recent California study reported the following prevalence rates among disadvantaged children age 8 months to 7 years when various diagnostic criteria were applied:

* Presence of any labiolingual lesion on the maxillary incisors -- 27 percent;

* Presence of at least 2 carious maxillary incisors -- 32 percent;

* Presence of at least three carious maxillary incisors -- 27 percent

* Five or more decayed, missing and filled teeth -- 36 percent.⁴

Another study on prevalence found that 50.2 percent of Native American Head Start children age 3 to 5 years had ECC.⁵

Costs

The cost of treating one child for ECC has been estimated to range from $700 to $1,000.⁶ Current dental practice recommends that these lesions be treated to help prevent caries in the permanent teeth and to guide the eruption of the permanent dentition. Cook found that the mean total cost of restoring an ECC patient requiring general anesthesia in a Choctaw Indian population was $2,142.⁵

A study of Canadian aboriginal children addressing issues related to the cost of treating ECC found that travel by the child and family to distant centers for treatment under general anesthesia by pediatric dentists was the usual method of treating affected children.⁷ Records of 884 children treated for ECC from 1980 to 1988 in Manitoba and related data on travel, lodging, medical, dental, hospital, and nursing costs indicated that treatment was significantly more expensive for the more remote groups than for those located closer to treatment centers (p < 0.001). This difference was primarily the result of travel and medical costs associated with hospitalization and the administration of general anesthesia. These findings suggest that resources should be allocated on the basis of regional need and that the development of community-based preventive programs and treatment programs could potentially save substantial treatment costs in preschool Canadian aboriginal children.⁷

Ramos-Gomez demonstrated that the cost of treatment for ECC in disadvantaged children in Northern California increased with the number of decayed, missing or filled teeth (dmft), ranging from $408 for dmft two through five to $1,725 for dmft 16-20.⁴ Many patients failed to comply with recommended treatment for reasons of cost. This study showed that:

* The prevalence of ECC varies depending upon the clinical criteria used for diagnosis;

* The cost of rehabilitating primary dentition increases in proportion to the number of teeth involved; and

* Parents of low-income patients avoid treatment of ECC for a variety of reasons related to the cost.

Although the proportion of affected children who receive restorative dental care is unclear, the potential costs associated with ECC are clearly large.

Effectiveness

Approximately 5.9 million U.S. children younger than 6 live in poverty.⁸ If 15 percent of these children each received $408 in restorative dental care (the lowest of the above estimates), the cost of treatment for caries in this population would be $361 million. Despite the large costs associated with ECC, no studies have examined the cost-effectiveness of ECC prevention programs. One impediment to such studies is the paucity of information about the effectiveness of preventive interventions for caries in children younger than 6. However, one recent study found that a fluoride varnish regimen reduced ECC by 40 percent to 51 percent among children age 4 to 5.⁹ Furthermore, fluoride varnish treatments inhibit ECC with reductions of up to 50 percent to 70 percent in pit and fissure surfaces and even higher in approximal surfaces.^10,11

In this paper, the authors have estimated the cost-effectiveness of prevention programs for ECC in a hypothetical cohort of 1-year-old children followed over a five-year period, making assumptions about the costs and impacts of a proposed program based on available evidence and, in some cases, clinical judgment. Although many of the estimates, admittedly, have wide margins of error, the cost-effectiveness analysis reported herein provides useful magnitudes and should serve as a useful conceptual framework for the guidance of policy in this area. Due to the lack of research data on this population of very young children, the estimates were based on information that came from a variety of sources, based on different experiences, and may be subject to limitations to its external validity. Because of these limitations, the estimates presented are not offered as definitive outcome measures, but rather as preliminary figures that may serve to guide policy makers until this model can be enhanced.

Study Methods

Definitions of Preventive Interventions

The authors analyzed three preventive interventions incorporating successive components of the Anticipatory Care Guidance: minimal, intermediate, and comprehensive, which incorporate four treatment components. The proposed minimal preventive program has two components: risk assessment and preventive treatment. The intermediate intervention adds another component, counseling. The comprehensive intervention adds a final component, outreach and incentives.

Treatment Components

* Risk assessment. Risk assessment is based on studies that indicate that the primary predictor of future caries is parental caries, sibling caries, inappropriate feeding practices, and characteristics of the behaviors of the parents or caregivers. Although some costly laboratory techniques can enhance risk assessment, for purposes of this study, the risk assessment would be based on information given at one annual visit to a pediatric dentist, beginning at age 1 year. Assumptions of risk assessment are presented under Incidence Rates.

* Preventive treatment. Preventive treatment is the application of fluoride varnish by a dental hygienist at six-month intervals based on the regimen of Twetman and colleagues.⁹

* Counseling. Based on the same recommendations as those for risk assessment, counseling of parents or caregivers would entail additional visits if the child is at high risk. The desired outcome of the counseling visits, besides delivering good oral health education, would be to achieve behavioral change in specific practices, and they would cover the topics of oral development, fluoride, oral hygiene/health, habits, nutrition and diet, and injury prevention, addressing age-specific issues for each topic according to the Anticipatory Care Guidance.

For example, a discussion of nutrition and diet for ages 6 to 12 months would focus on the issues of ECC tooth decay pattern and the role of consistency of sugar in caries, with recommendations to encourage weaning at the appropriate time. At 12 to 24 months, the issues would include plaque and the role of frequency of sugar in caries, with discussions of carbohydrates contributing to caries as well. From 2 to 6 years, the focus would shift to snacking and sugar intake at home and at school, the use of food to reinforce behavior, and the relationship of a healthy diet to oral health, with advice to review the child’s diet and to refrain from using food as a behavioral tool. Each topic is similarly outlined with issues and actions according to these age groups.

* Outreach and incentives. Outreach and incentives are intended to reinforce attendance at the annual assessments and to reinforce practice of the habits recommended in the counseling visits. The outreach consists of telephone and personal prompts as well as advocacy by a public health dental hygienist, as practiced in the Spokane Access to Baby and Child Dentistry Program of the Spokane Dental Prevention Project in Spokane, Wash. That program alleviated disruptions arising from broken appointments and bringing siblings to the dental office.¹² The outreach is estimated to cost $4 per patient, based on the labor cost of the public health dental hygienist. Incentives are assumed to consist of a $5 voucher for toys or a prepaid phone card. The incentives are contingent on increases in the assessed knowledge of the caregiver (e.g., not putting a child to sleep with a bottle) and favorable results of risk assessment. One-third of Medicaid recipients are assumed to be eligible for a $3 transportation benefit, which, when spread over all patients, results in an average cost of $1 per visit. The $10-per-child cost of the incentive and outreach intervention is the sum of the $4 outreach cost, the $5 incentives cost, and the $1 transportation benefit cost.

Derivation of Cost Savings

* Prevention costs. The estimated cost of each intervention was based on 1996-97 California Dental Medicaid (Denti-Cal) reimbursement rates¹³ and rates for the Spokane Dental Prevention Project.¹² Table 1 sets forth the recommended frequencies of the interventions and their costs. Although only 16.8 percent of children age 1 through 5 received an initial assessment in 1993 under Medicaid,¹⁴ for this paper, the authors estimate that 75 percent utilization rates would be achieved for all interventions, based on preliminary results from the Spokane Dental Prevention Project.

* Treatment costs. Treatment costs were derived from a group of 115 patients with ECC treated at the pediatric dental clinic at the University of California at San Francisco in 1992. Patients were assigned to the following four categories, according to dmft: 2 to 5, 6 to 10, 11 to 15, and 16 to 20. The average cost of treatment for each category was: $408 (dmft 2 to 5), $950 (dmft 6 to 10), $1,488 (dmft 11 to 15), and $1,725 (dmft 16 to 20).⁴ The overall average treatment cost per surface ($112) was calculated by averaging the average cost per surface in each dmft category based on the midpoint of the category ($117, $119, $115, and $96, respectively).

* Incidence rates. Table 2 sets forth the assumptions used to derive incidence rates for the analysis. Based on conservative preliminary data from an underserved group of young children, it was assumed that the proportion of children at high risk of ECC would increase from 0.20 in year 1 to 0.50 in year 5. Second, it was assumed that in the absence of a preventive intervention in a nonfluoridated area, the incidence of ECC would be 10 new carious lesions per 1,000 surfaces per year in low-risk children and 48 new carious lesions per 1,000 surfaces per year in high risk children. The number of new carious surfaces was derived by multiplying the annual carious lesion incidence rate by five (the number of surfaces per tooth) times the number of teeth present. The authors calculated that in the absence of preventive interventions, the annual incidence would be 2.31 carious surfaces per child in a cohort from a nonfluoridated area. In a cohort from a fluoridated area, the incidence of carious surfaces would be 40 percent lower than in a nonfluoridated area, or 1.38 surfaces per child per year. Approximately 16 percent of children in California live in fluoridated areas.¹⁵ Thus, in the absence of the proposed preventive interventions, children in California age 1 to 5 years would have an annual incidence of 2.16 carious surfaces per child, which is the weighted average of 2.31 in nonfluoridated areas and 1.38 in fluoridated areas.

* Cost-effectiveness. The term "cost-effective" can have varying meanings.¹⁶ The most common meaning is that a proposed intervention produces a superior outcome at a reasonable cost in relation to the improvement achieved.¹⁷ In that case, cost-effectiveness is expressed as the cost per unit improvement in outcome. It is calculated as the net cost of the proposed intervention divided by the improvement in outcome. The most stringent meaning of cost-effectiveness, more precisely termed "cost saving," is that a proposed intervention is "less costly and at least as effective" as the status quo.¹⁸

Results

Table 3 sets forth the five-year costs associated with the interventions, the effectiveness estimates, the effect estimates, and the costs required to achieve the effects. The cost per carious surface averted was derived by dividing the five-year cost by the five-year effectiveness in carious surfaces averted.¹⁸ The authors assumed that the minimal intervention (exam and varnish) would be 40 percent effective, that the intermediate intervention (exam, varnish, and counseling) would be 70 percent effective, and that the comprehensive intervention (exam, varnish, counseling, and outreach) would reach the goal of 80 percent effectiveness. The 40 percent effectiveness assumption for the exam and varnish intervention was based on the lower bound of effectiveness reported by Twetman and colleagues.⁹ The 70 percent and 80 percent effectiveness assumptions are based on clinical observations at the UCSF Pediatric Dental Clinic. Given these assumptions, the number of carious surfaces averted in each child in the California cohort would range from 4.32 to 8.60 over five years. The intermediate intervention is the most cost-effective, as its cost per carious surface averted is the lowest ($65.74). Dividing the cost per carious surface averted ($65.74) by the cost of treatment per surface ($112) yields a cost saving threshold of 59 percent. Thus, the authors' proposed interventions would be cost saving if at least 59 percent of the carious surfaces would have been treated. While current treatment rates are probably lower in disadvantaged children, these treatment rates are already reached in less deprived populations and will be met in the future in poorer populations.

Discussion

This study was limited by the shortage of data that address the cost of treatment, the cost of prevention, or the effectiveness of preventive interventions for carious lesions in children younger than 6. Although the authors have used the best available data, the margin of error for the estimates is admittedly large. Future studies should test the accuracy of the assumptions with respect to the cost of treatment and prevention and the effectiveness of preventive interventions. Among the factors that should be addressed by future research are lack of compliance with the recommended regimen, loss to follow-up, in-migration and out-migration, the time out of work for the parents, and the psychological trauma for a child to undergo emergency dental treatment at such an early age.

Conclusions

Policy makers should consider subsidizing and promoting preventive interventions for ECC for two reasons: First, the interventions will have a substantial impact on the oral health of a particularly vulnerable population of children, reducing ECC by 40 percent to 80 percent as assumed in the study results. Second, when the cost of the interventions is compared to the cost of treatment, part of the costs will be offset by savings in treatment costs. Furthermore, the interventions are likely to save costs as dental treatment becomes more widespread. Moreover, the increased benefits would include ensuring that the first dental visit for a very young child is free of pain and trauma, increasing acceptability of dental procedures, and, most important, improving access to oral health for children from underserved communities at risk. Federal, state, and local agencies would experience considerable savings in treatment costs, which could then be used for more vast and effective preventative and innovative programs for the enhancement of oral health and oral disease prevention targeted for pregnant women, babies, and preschool children.

Acknowledgments

The authors are grateful to Mr. John Hollinsworth, Dr. Peter Milgrom, the Spokane Partnership Program, Dr. Jane Weintraub, Dr. Scott Tomar, Dr. Stuart Gansky, Dr. Robert Isman, and the Hispanic Dental Association/Early Childhood Caries Panel members for their support and guidance for the development of the proposed model.

Authors/

Francisco J. Ramos-Gomez, DDS, MSc, MPH, is an assistant professor in the Department of Pediatric Dentistry at the University of California at San Francisco and the director of Pediatric Services at San Francisco General Hospital.

Donald S. Shepard, PhD, is a research professor at the Institute for Health Policy, Heller School, Brandeis University.

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To request a printed copy of this article, please contact/Francisco Ramos-Gomez, DDS, MPH, MSc, UC San Francisco, 707 Parnassus Avenue, Box 0438, San Francisco, CA 94143.