Document Type


Date of Degree

Spring 2015

Degree Name

PhD (Doctor of Philosophy)

Degree In

Oral Science

First Advisor

Damiano, Peter C

First Committee Member

Buresh, Christopher T

Second Committee Member

Caplan, Daniel J

Third Committee Member

Jones, Michael P

Fourth Committee Member

Kuthy, Raymond A

Fifth Committee Member

Momany, Elizabeth T


Avoidable use of the Emergency Departments (EDs) constitutes a significant public health problem, which has health, economic and ethical implications. The factors that affect avoidable use of the EDs are complex and poorly understood. The goal of this dissertation was to examine the role of medical home in avoidable pediatric ED visits, assess the impact of Medicaid policy on ED visits for dental problems and assess the factors affecting follow-up dental care after a dental ED visit.

Iowa Household Health Survey data was used for the first study, which included a sample of families with at least one child residing in Iowa. It was found that 68% of parents who took their child to an ED in the previous year thought the ED visit could have been avoided if primary care was available to them. Having a medical home was not found to be associated with pediatric ED visits; however, food insecurity was significantly associated. Parents of children with public insurance, those who were not referred by a healthcare provider and those who reported difficulty in getting routine care appointments were more likely to report an avoidable ED visit by their child.

The second study examined a policy change in California where Medicaid eliminated its comprehensive adult dental coverage on July 1, 2009. State Emergency Department Database were obtained from Agency for Healthcare Research and Quality for California for 2006 through 2011. Interrupted time series, a quasi-experimental approach of was used to examine the impact of the policy change on rate of dental ED visits by Medicaid enrolled adults. Segmented linear regression revealed that policy change led to an immediate significant increase in the rate of dental ED visits. The policy had a differential impact on various subgroups based on age, race-ethnicity and residential location. The annual costs associated with dental ED visits made by Medicaid adults also increase 68%.

Survival analytic approach was used in the final study to examine the patterns of dental care following a dental ED visit by Medicaid enrolled adults in Iowa. Medicaid claims and enrollment data were used to identify adults with an index dental ED visit in 2011, and then each subject was followed for up to 6 months. About 52% of all adults who satisfied the study inclusion criteria, had a follow up dental visit within 6 months of the index dental ED visit. Cox regression model revealed that adults who had visited a dentist in the year prior to the ED visit had greater hazards of having an early dental follow up after the ED visit. Having repeated dental ED visits was found to have a dose-response relationship to follow-up time to dentist visit, with those having 1 repeat ED visit having 53% hazards and those with 2 or more repeat ED visits having 34% hazards of having a follow-up dentist visit, compared to those with no repeat ED visits.

Collectively, the results from this dissertation provide important insights in understanding the complex problem of avoidable ED visits. Factors such as food insecurity and medical home need to be further investigated in their association with avoidable ED visits. State Medicaid policy plays an important role and limiting Medicaid adult dental coverage may lead to an increased reliance of the affected population on EDs for dental care. However, EDs do not provide any definitive dental care, and our results indicate that almost half of the adults with dental ED visit do not have a follow-up dentist visit in the next 6 months.

Public Abstract

Avoidable use of Emergency Departments (EDs) is a complex problem, which has significant health, economic and ethical implications. It has been attributed as a major cause of increasing healthcare expenditures in the US. However, the reasons behind such avoidable use of the EDs are poorly understood. This dissertation comprised of three studies. The first study examined factors associated with avoidable ED use by children in Iowa, and found that a majority of parents think that their child’s ED visit could have been avoided if primary care alternatives were available to them. The second study examined the impact of elimination of comprehensive dental coverage for Medicaid-enrolled adults in California on July 2009, which left more than 3 million low-income adults without dental coverage. We found that this policy change led to an increased use of EDs for dental problems by Medicaid adults. EDs do not provide any definitive dental care, so these patients still need to see a dentist to resolve the underlying dental problem. The final study examined time to follow-up visit to a dentist after Medicaid-enrolled adults visit an ED for dental problems. We found that almost half of those who go to the ED do not have a follow-up dentist visit within 6 months. These results highlight the poor state of access to dental care for low-income adults, and support Medicaid coverage of adult dental services. The current health policy environment offers a unique opportunity to improve the access to dental care for low income adults.


publicabstract, access to dental care, dental emergency, emergency department, follow-up, medicaid, medical home


xvi, 288 pages


Includes bibliographical references (pages 273-288).


Copyright 2015 Astha Singhal