In the United States and other developed nations, primary care providers (PCP) play the leading role in preventing and managing chronic illnesses such as diabetes. In fact, 80–90 % of adults with diabetes receive their care exclusively from their PCP [13, 14]. A hallmark of primary care is the provision of broadly accessible care, which considers multiple determinants of health, and is coordinated among the patient, family, community, and other health-care providers. During visits with their PCPs, many processes of care including ordering proper laboratory tests (i.e., HbA1c, lipid levels, and urine micro-albumin tests), adjustment of medications, and management of complications and behavior changes need to be fulfilled. Each of these should occur while considering individual patient’s co-morbidities, preferences, and social and financial concerns. Many providers report diabetes to be harder to treat than other conditions such as hypertension and angina [12]. Given the complexity of providing such comprehensive diabetes care, it is no wonder that PCPs often struggle to achieve all of these goals in a traditional 15- to 30-min patient encounter. Diabetes specialists face many of the same challenges. In fact, although endocrinologists are more likely to perform evidence-based recommended processes of care for diabetes management, studies have not shown consistent differences in outcomes between primary care physicians and diabetes specialists [15–17]. This suggests that while individual providers can improve their knowledge of evidence-based guidelines and address the unique challenges that may prevent individual patients from achieving optimal diabetes control, both PCPs and specialists are operating in a broader system that makes improving diabetes care challenging.

Historically, health-care systems have centered on individual providers reacting to acute illnesses. As chronic diseases have become the leading causes of morbidity and mortality, the need to shift to a more proactive, multi-disciplinary, coordinated, team-based approach to care has emerged [14, 18]. Unfortunately, many individuals living with diabetes do not experience this model of care. This was demonstrated by the Diabetes Attitudes, Wishes, and Needs (DAWN) Study, an international survey of randomly selected generalist and specialist physicians and nurses, and patients with diabetes. The DAWN study revealed that the majority of patients did not receive diabetes care with a multi-disciplinary team of providers, including a PCP or diabetes specialist, diabetes nurse, dietitian, eye doctor, foot doctor, and behavioral specialist [19].

In addition to the DAWN Study based on patient surveys, additional research published over the last decade and a half has helped to paint a fuller picture of the current status of chronic disease management and diabetes care. This research has revealed that practitioners were not following established clinical guidelines, were not coordinating care with each other, and were not actively following patients to ensure optimal outcomes. At the same time, this research revealed that patients were not adequately trained to manage their own illnesses [20]. To address these deficiencies among practitioners and patients, one of the most prominent models of care has been the Chronic Care Model (CCM), which has been extensively applied to diabetes care. The CCM system shifts care from the traditional model of health-care to one that is proactive in managing chronic diseases. The CCM is built upon the principle that optimal chronic disease management necessitates a health-care system composed of six connected components. It includes leadership that encourages a culture of quality improvement and provides the resources needed to change delivery system design. Delivery systems should be planned to provide coordinated care, structured to prevent rather than react to disease complications. The next component is decision support, which equips providers with evidence-based guidelines that should be considered along with patient preferences to guide care decisions. The CCM also incorporates clinical information systems to organize patient and population data (i.e., registries) and provides reminders to patients and physicians to enable proactive care. The next component empowers patients to play the leading role in the management of their disease by providing education and enabling self-management support. Finally, policies and community resources to improve patient access and care should be in place [20]. Collaboratively, these six components are designed to improve population health in a way that makes it easier and more efficient to address individual patients’ needs. In 2013, a systematic review of 16 studies, in which the CCM was applied in primary care settings providing diabetes care, showed that the CCM was effective in improving diabetes care and clinical outcomes [21]. The authors and others acknowledge that further work is needed to determine how well the CCM is helping patients and providers manage their diabetes and how the CCM can be more easily integrated into smaller or less motivated practices with fewer resources [22]. Nevertheless, in promoting strategies to improve diabetes care, the American Diabetes Association has endorsed the CCM and noted that, “care should be aligned with components of the CCM to ensure productive interactions between a prepared proactive practice team and an informed activated patient” [7].

A key component of the CCM is the electronic health (EHR) or medical record, which not only enables providers to efficiently navigate through individual patient records, but also readily allows for population-based management. Use of EHR has been shown, across a broad range of practices, to lead to improved outcomes. In a study of 27,207 diabetic adults seen in 46 practices, EHR practices had a 35.1 % increase in process measures of checking HbA1c, testing for urinary micro-albumin, prescribing angiotensin-converting-enzyme inhibitor or angiotensin-receptor blocker medications, performing screening eye examinations, and providing a pneumococcal vaccination. Albeit slightly lower, improvement in intermediate outcomes—HbA1c, BP, LDL, body-mass index, and nonsmoking status—was also 15.2 % higher in EHR practices [23]. Nevertheless, even with federal incentives and “meaningful use” guidelines to promote implementation of EHR, more research on how to use EHR in an efficient manner is needed [24].

The patient-centered medical home (PCMH) has emerged as another model for chronic disease management and prevention in primary care and been described as “a vehicle to adopt the Chronic Care Model.” [25] The PCMH is built on the principle that management of chronic care should include the following basic elements: (1) coordination and integration of care to guide the patient through the health system; (2) a focus on quality and safety which incorporates up-to-date guidelines, is applied consistently, and is incorporated into patient registries so that performance can be tracked; (3) whole person orientation which focuses on primary, secondary, and tertiary prevention; (4) a personal physician who is a first contact for the patient, is aware of individual psychosocial and cultural components that may influence a patient’s health, and, among members of the health-care team, who serves as the lead coordinator of the patient’s care, (5) enhanced access with flexible scheduling and easy access to members of the team, and (6) a system where quality improvement and care coordination is appropriately reimbursed. Practices that are recognized as a PCMH receive a per member per month fee in addition to regular reimbursement through fee-for-service.

PCMH interventions have been studied a great deal and more pilots are underway. In a recent study, 8 PCMH pilots, from geographically diverse settings, were reviewed and noted to report outcomes data. All have led to variable improvement of intermediate outcomes including improved HbA1c, BP, and LDL control, and several have shown reduced emergency room and inpatient admissions, cost savings, and improved patient satisfaction [25]. Of note, all of these programs included a structured role for care coordination, in most cases, through a case manager. In a meta-analysis of quality improvement strategies and glycemic control, case management and team changes, which add additional health-care providers to the patient’s care team, or expand the role of an existing nurse or pharmacist, were identified as the two most effective strategies in improving patient outcomes [26].

There have been a few large prospective studies designed to evaluate the effectiveness of similar multi-component system change models. The Translating Research Into Action For Diabetes (TRIAD) Study was a multi-center study which gathered a cohort of 180,000 demographically and geographically diverse diabetic individuals from 10 different health plans—including for-profit, not-for-profit, Medicare, and Medicaid plans—and 68 provider groups delivering primary and specialty care. TRIAD investigators found that performance feedback, physician reminders, and structured care management were each strongly associated with better care processes (periodic HbA1c testing, lipid testing, micro-albuminuria testing, retinal examinations, foot examinations, smoking cessation counseling, aspirin prescription). However, process of care rankings were completely unrelated to rankings for actual health outcomes, specifically HbA1c and BP control. The data also showed that patients with co-payments or co-insurance had lower rates of self-monitoring of blood glucose and were less likely to use recommended medications. In fact, those patients who cited that out-of pocket costs were a barrier to self-management had significantly less control of HbA1c, BP, and LDL [8].

The TRANSLATE trial was a randomized clinical trial conducted in 24 primary care practices and included over 8000 patients. The intervention began with identifying high-risk individuals and included an electronic diabetes registry, visit reminders, patient-specific physician alerts, a site coordinator who managed clinic operations and planning, and monthly performance review with a local physician champion. This study was notable in that not only did process measures improve, but so did intermediate clinical outcomes which included significantly decreased HbA1c, BP, and LDL in intervention patients [13].