Rural-Urban Differences in Continuity of Care among Medicare Beneficiaries
Background
In response to the Affordable Care Act and other reforms in the health care market, new models of care are being tested and implemented across the country. Care and payment models such as patient-centered medical homes, Accountable Care Organizations (ACOs), and bundled payments depend on linkages between different types of health care providers to ensure continuity of care. To address concerns that health care in rural areas may be more fractured and thus a difficult place for these models to succeed, we measured continuity of care using detailed data on a sample of Medicare beneficiaries from 2000-2009. Although continuity of care is a multifaceted concept, here we define it as the degree to which a patient’s care is concentrated among few providers. METHODS We measured continuity of care in the outpatient setting using the Bice-Boxerman Continuity of Care Index (COCI).1 The COCI is a widely used, validated measure of the dispersion and concentration of care across all providers seen by a patient.2 Values range from nearly 0 (where the beneficiary sees multiple physicians once) to 1 (where the beneficiary sees only one provider). Thus, higher values denote higher continuity of care among fewer providers. It is important to note that higher values are not necessarily optimal; for beneficiaries with complex health needs, it may be appropriate to see multiple specialists and thus have lower continuity of care. One drawback of the index is that it has no intuitive interpretation (that is, it is not a percent or proportion); based on one study, a difference of 0.05 is the minimum clinically meaningful difference. Because rurality is a nuanced concept, we defined rurality based on three alternative definitions: 1) the U.S. Office of Management and Budget (OMB) Metropolitan Statistical Areas (metropolitan and nonmetropolitan with nonmetro further divided into micropolitan and noncorebased areas); 2) ZIP Code approximations to Rural-Urban Commuting Area (RUCA) codes classified into four groups: Urban, Large Rural, Small Rural, Isolated;3 and 3) the Office of Rural Health Policy definition [all nonmetropolitan and metropolitan with a (ZIP-approximated) RUCA of 4-10].4