The federal Patient Protection and Affordable Care Act (ACA), signed into law on March 23, 2010, changes the landscape of U.S. health care through expanded insurance access, enhanced consumer protections, emphasis on wellness and disease prevention, and cost control. This dissertation is composed of three papers that investigate aspects of preventive services. The studies use nationally representative data from the National Survey of Family Growth and the Medical Expenditure Panel Survey and employs Andersen's Behavioral Model of Health Services Use as a theoretical model.

The first study explores the relationships between use of various preventive services and being uninsured. The study employs multivariate logistic regression analyses to estimate variation in receipt of eight preventive services by race/ethnicity among adults aged 18 years and older uninsured in the previous year. The second article focuses on expanded access to health insurance in young adults and how this relates to the use of contraception and unintended pregnancy. This study used a difference-in-differences approach in order to identify a causal relationship between the policy and outcome. The third article examines colorectal cancer screening practices in the Medicare population before and after Medicare rules changes stemming from the ACA regarding reimbursement of screening procedures. Multivariate and single difference multivariate logistic regression models were estimated to examine trends and racial/ethnic differences in colorectal cancer screening over the 2007 to 2012 period.

The results show how important it is to understand the determinants of preventive service access among a variety of population subgroups. With the introduction of the Affordable Care Act, health systems require strategies to determine what policy, system, and administrative methods are most effective in improving the uptake of preventive services and reducing disparities. This dissertation addressed policy influences on screenings and provided information on the impact of policies on use of preventive services as well as on reducing the disparities among subpopulations. Improved access to health insurance and better coverage of preventive services are necessary mechanisms to increase service utilization in the United States, but these may not be sufficient to actually realize improved utilization.