Dissertation Title："Unaffordable Care: Health Care Access and Economic Burden in the Asia Pacific and U.S."

Out-of-pocket payments are an important source of health care financing in many countries. However, when care is unaffordable, patients either pay for services and experience financial burden or forgo care and face potential health consequences. This dissertation explores both aspects of health care affordability—economic burden and access—in the Asia Pacific and U.S. and addresses two questions: First, how best do we measure economic burden arising from health care payments? Second, do health insurance policies with substantial cost sharing reduce access to essential care?

The first paper assesses the utility of five survey measures of economic burden due to health care payments. Using 2002/03 expenditure and coping strategy data from households in China, Malaysia, the Philippines, and Vietnam, we find that measures of impoverishment and indebtedness showed the strongest evidence of construct validity, while other measures such as catastrophic health expenditure did not consistently predict degree of economic burden.

The second and third papers investigate whether a high-deductible health plan (HDHP) in the U.S. diminished access to essential care, using 2001–2008 administrative claims data. In paper two, we used interrupted time-series to examine the effect of an employer-mandated switch from traditional HMOs to HDHPs on the use of chronic medications that were exempted from the deductible. When HDHP members faced modest drug copayments, medication use for chronic illnesses was largely preserved, save for a possible small decline in diabetes drugs. In paper three, we employed a difference-in-differences framework to examine the impact of the plan switch on rates of outpatient visits and diagnostic tests. HDHP enrollment was associated with moderate reductions in visits for chronic higher-priority conditions, which required modest copayments, and general lab tests, which had full cost sharing under the deductible. Fully covered preventive lab tests did not decline. Chronically ill HDHP members who have more contact with the health care system might be more likely to reduce utilization because of increased exposure to cost sharing, even with low out-of-pocket costs for visits. Selectively extending first-dollar coverage to additional high-value outpatient services, such as chronic higher-priority visits, may be necessary to maintain access to essential care.