Effects of Health Insurance on Osteoporosis Medication Use among U.S. Women

Background:Osteoporosis is a major public health concern and its prevalence continues to increase in concert with demographic changes in the U.S. In the past decade, treatment and prevention of osteoporosis changed due, in part, to findings from the Women’s Health Initiative (WHI) and pharmaceutical advances. Prescription drugs, often obtained through insurance coverage, are an integral component of osteoporosis treatment and prevention. However, osteoporosis medications are usually expensive and patients without health insurance coverage can face a high financial burden of treatment, which may result in costs-related barriers to appropriate and timely use of medications. Even for patients with health insurance coverage the costs of medications may be prohibitive. To date, a number of studies have examined the effects of health insurance coverage on health resource use overall, in specific populations and in other disease areas. However, the extent to which health insurance coverage enables women to better respond to recent changes in treatment guidelines and advances in osteoporosis pharmacotherapy is poorly documented.

Objective: This study will use nationally representative data on post-menopausal women in the U.S. to examine the prevalence and trends in osteoporosis medications use since the initial publication of the WHI study. This study will also examine the effects of health insurance coverage on osteoporosis medications using regression based methods that account for the potential endogeneity of health insurance coverage.

Data and Methods: The data for this study will be drawn, primarily, from the 2002-2011 Medical Expenditure Panel Survey (MEPS). MEPS Prescribed Medicines files will be used to determine the classes of drugs prescribed for each individual with osteoporosis, classifying medications based on treatment only, prevention only, and treatment and prevention. In addition to the rich array of socio-demographic, economic, health and geographic variables, the MEPS data would be linked to other secondary data sources to exploit state and county-level variables that may affect prescription drug use. The study will describe differences in osteoporosis prevalence and medication use by health insurance coverage as well as trends in osteoporosis medications use overall. Studies of the effects of health insurance coverage on health care use suggest that health insurance is associated with an increased use of health care. However, the direction of causality, and ultimately, the effect on health care use is not unambiguous. Instrumental variables (IV) method is one approach to dealing with potential endogeneity of the health insurance coverage variable. This study will implement an IV estimation of the reduced form relationship between health insurance coverage and osteoporosis medication use – using state and county level variables as instruments for health insurance coverage. The study will also test the sensitivity of regression models to alternative specifications.

Potential Policy Implications: Despite the availability of new and existing osteoporosis medications, the high cost of these prescription drugs remains a concern for individuals, the public and policymakers. This study will provide insights into the role of health insurance coverage in enabling women and their families to respond to recent changes in treatment guidelines and the introduction of new osteoporosis pharmacotherapy.