Assessing Community Cancer Care After Insurance ExpanSionS

Cancer morbidity and mortality is greatly reduced through screening and prevention, but uninsured patients are much less likely than insured patients to receive these evidence-based services as recommended. In addition, uninsured cancer survivors receive fewer primary and preventive care services than those with health insurance. Thus, it is hypothesized that Affordable Care Act (ACA) Medicaid expansions could substantially improve access to essential cancer preventive and screening services for previously uninsured patients, and facilitate better care for cancer survivors who gain health insurance. In 2012, the United States (US) Supreme Court ruled that states were not legally required to implement ACA Medicaid expansions, creating a unique natural experiment to test this hypothesis. By April 1, 2015, 30 states and the District of Columbia had implemented expansions, and 20 states had not. This led to increased Medicaid enrollment by 26% in expansion states, compared to 8% in non-expansion states. Previous single-state Medicaid expansions led to increased utilization of healthcare services and improved health outcomes post-expansion. For example, in Oregon, cervical cancer screening rates were 18-19% higher among women who gained Medicaid in 2008, compared to those who remained uninsured. However, no previous assessments of state-specific expansions had concurrent control (non-expansion) states for comparison. Further, little is known about how Medicaid expansion impacts the delivery of recommended primary and preventive care services to cancer survivors, termed 'survivor care.'

The investigators propose to use the ACA Medicaid expansion natural experiment to study the effect of state-level Medicaid expansion on rates of cancer screening and preventive services ('cancer prevention') and survivor care. Many patients likely to gain coverage through ACA Medicaid expansions receive primary care in community health centers (CHCs), our nation's healthcare 'safety net;' thus, the proposed analyses will use electronic health record (EHR) data from the ADVANCE clinical data research network (CDRN) of CHCs (ADVANCE is one of 11 CDRNs in the national PCORnet data network). The ADVANCE CDRN has patient-level data from 476 CHCs in 13 Medicaid expansion states (n=576,711 patients) and 242 CHCs in 8 non-expansion states (n=361,421 patients). This nationally unique data resource will allow us to measure outcomes in expansion versus non-expansion states, illuminating the impact of increased Medicaid opportunities on rates of cancer prevention and survivor care within the safety net. The investigators will also assess whether disparities in delivery of this care are reduced. Our specific aims for this study, titled "Assessing Community Cancer care after insurance ExpanSionS (ACCESS)," are to:

Aim 1. Compare pre-post receipt of cancer prevention and screening among vulnerable CHC patients in Medicaid expansion versus non-expansion states.

Hypothesis 1a: Cancer prevention and screening will significantly increase among CHC patients in expansion states, compared to those in non-expansion states.

Hypothesis 1b: Racial/ethnic disparities in cancer prevention and screening will be significantly reduced in expansion states versus no change in non-expansion states.