Diabetes and Aging: Meeting the Needs of a Burgeoning Epidemic in the United States

Abstract

In the United States, one out of every four adults over the age of 65 has diabetes and one half of all adults in this age group are prediabetic, placing them at high risk for developing the disease. Beyond the United States, many other countries are also facing aging populations and high obesity rates that contribute to a staggering global diabetes epidemic. The care of the older patient with diabetes is frequently challenging, due to the accumulation of diabetic complications, extensive comorbidities, and functional impairments. Compounding this challenge is the lack of directly available evidence to guide management and care in this population. Though the global community shares in the epidemiologic burden of diabetes, there are large disparities across health systems and nations in the allocation of resources to the prevention, diagnosis, and treatment of the disease. Yet there is a consistency across many countries in the sub-optimal glycemic control and health outcomes for a majority of diabetics. This article reviews the context in which health systems provide diabetes care for the elderly and provides a framework for policy makers to support comprehensive diabetes care in the older adult. Nearly half of global diabetes expenditures occur in the United States, where only 6% of the world’s diabetics reside. This article focuses on how to improve diabetes care in the United States, given its disproportionate contribution to global diabetes expenditures. Many of the recommendations presented, however, may be adapted and applied to other health systems.

INTRODUCTION

There are an estimated 29.1 million Americans with diabetes.¹ Type 2 diabetes is a disease of aging, characterized by insulin resistance and diminished pancreatic insulin secretion. As individuals age, other factors such as increased adipose tissue, decreased muscle mass, comorbid medical conditions, decreasing mobility, or requiring medications that raise blood sugars and changes in nutritional intake all contribute to the significant rise in diabetes prevalence associated with aging. In the United States, it is estimated that 25.9% of the population older than 65, or approximately 11.2 million older adults, are affected by the disease and, with the aging of the population, this number is expected to rise rapidly (Fig. 1).¹ The United States is not alone in its struggle with this burgeoning epidemic. The International Diabetes Federation (IDF) anticipates that, over the next 20 years, the global prevalence of diabetes is expected to soar from 382 million to 592 million people, with almost half of these individuals being undiagnosed.² Even without diagnosis, many of these individuals will develop diabetes complications and face an increased mortality risk. Given the high prevalence of diabetes in older adults and the individual health and economic tolls imposed by the disease, policy makers have an imperative to recognize the need for reforming diabetes care and emphasize diabetes prevention for the next generation of older adults. This article reviews the present state of diabetes care in the United States, discusses gaps in current diabetes care delivery systems, and provides a call to action along with a comprehensive framework for diabetes care in older adults. This article focuses on how to improve diabetes care in the United States, because nearly half of global diabetes expenditures occur in this country, where only 6% of the world’s diabetics reside. Many of the recommendations presented, however, may be adapted and applied to other health systems.

FIGURE 1.

Prevalence of Diabetes in Older Adults. More Than Three Out of Four Older Adults Have, or Are at Risk for, Diabetes in the United States. Source: Adapted from Ref. 1

HEALTH BURDEN IMPOSED BY DIABETES

Diabetes is often accompanied by other comorbid conditions, many of which affect quality of life in older adults. Among Medicare beneficiaries with diabetes, more than 95% have at least one other chronic health condition, and approximately one third have five or more additional chronic conditions.³ As individuals with diabetes grow older, they frequently develop diabetes complications such as cardiovascular and kidney disease, neuropathies, peripheral vascular disease, and vision impairment—each of these complications is more likely to occur with increased duration of the disease.⁴ Additionally, older diabetics are more likely to develop comorbid conditions and geriatric syndromes, such as depression and cognitive dysfunction, which can result in or occur in the context of diminished functional status, physical disability, frailty, and reduced health-related quality of life.^5,6 As a result of these factors, the disease becomes an increasingly heterogeneous condition with aging. It has been estimated that, on average, a middle-aged diabetic adult dies six years earlier than a nondiabetic adult and that only 60% of this difference in survival can be explained by death from vascular causes.⁷ Diabetic adults, for example, have also been shown to be at increased risk for death from certain cancers such as liver, pancreas, endometrium, colon, rectum, and breast.⁸

ECONOMIC BURDEN OF DIABETES

In addition to its health implications, diabetes imposes a significant economic burden at both the individual and health systems levels. For individuals who have been diagnosed with diabetes, medical expenditures are on average 2.3 times higher than for nondiabetics.⁹ Unfortunately, as individuals age, the burden of health care costs often grows. Despite broad coverage with Medicare in the United States, older individuals are still exposed to high out-of-pocket expenses in the form of high deductibles and copayments. In 2007, for example, out-of-pocket expenses for Medicare beneficiaries accounted for an estimated 11.0% of income in individuals ages 65–69, while soaring to 27.8% for adults older than 85 years.¹⁰ In an international survey of over 15,000 adults from 11 industrialized nations, out-of-pocket expenses were found to pose more of a burden on older adults in the United States than in other nations.¹¹ The survey found, for example, that 19% of adults over age 65 surveyed in the United States forgo health care, including visiting a doctor, skipping a recommended medical test or treatment, filling prescriptions, or skipping medications, due to high out-of-pocket costs. This can be contrasted with France, where only 3% reported skipping health care due to costs, and Norway and Sweden, where only 1% of older adults reported trouble with paying medical bills. Diabetes is among the most costly of chronic diseases to manage, with an estimated 1 in 10 US health care dollars being directly attributable to diabetes-related care.⁹ According to an American Diabetes Association Scientific Statement on the costs of diabetes care in the United States, the estimated total economic cost of diagnosed diabetes in 2012 was 245 billion USD, representing a 41% increase from the estimate just five years prior.⁹ This number does not account for additional costs for the 8.1 million individuals with undiagnosed diabetes. In the United States, over the next 20 years, it is estimated that one third of the 44.1 million individuals with diabetes will be older adults and that expenditures for diabetes-related care in this group will quadruple, posing an economic threat to both individual and national economic security.¹²

The global community faces a similar economic burden. In developing countries, increasing population sizes, longer life spans, and diet and lifestyle changes associated with urbanization have all contributed to the rising diabetic population.² More than one tenth of all global health expenditures are spent on diabetes.² Nevertheless, across different regions and countries, there are stark disparities between the burden of disease for diabetes and where health care resources are allocated. Whereas 80% of diabetics are from low- or middle-income countries, only 20% of the 548 billion USD spent on diabetes care in 2013 was from these countries. According to the IDF, though 6.4% of the world’s diabetics are from the United States, US expenditures for diabetes care in 2013 comprised 44% of total global expenditures for the disease. This can be contrasted with India, for example, where more than 17% of the world’s diabetics are from, yet just below 1% of the world’s diabetes expenditures are spent.² It is clear that although the battle against diabetes is shared by the world, available resources and strategies to combat it vary by country and region.

DISPARITIES IN DIABETES CARE

Within both developed and developing nations, there are significant disparities in diabetes care persisting into older age. The IDF notes that for older people from minority groups in Western societies, diabetes care is characterized by poor access to services, lack of educational resources, and poor follow-up practices.¹³ Among Medicare beneficiaries in the United States, data from 1993–2001 showed that the highest prevalence and incidence of diabetes among the elderly were among minority groups, including blacks, Hispanics, and Asians. During this time period, Hispanics and Asians saw the most rapid rise in the prevalence and incidence rate of diabetes.¹⁴ African American and Hispanic patients are more likely to have poor glycemic control and higher rates of complications than white patients.¹⁵ Similarly, elderly low-income diabetic patients have been shown more likely to be of minority race/ethnicity, have comorbid complications, and utilize emergency departments and hospitalizations for diabetes care. At the same time, they are less likely to receive care from an endocrinologist or to receive important processes of care such as hemoglobin A1c (HbA1c) testing, lipid evaluation, and ophthalmologic evaluation.¹⁶

Within the 47 countries comprising the IDF European region, there are also substantial disparities in access to diabetes care, education, medications, and devices.¹⁷ In the United Kingdom, where universal health coverage is available through the National Health Service, there were no significant differences in process measures such as measurement of blood pressure, HbA1c, or screening for kidney or eye disease between ethnic groups. However, blacks and South Asians were significantly less likely to achieve all treatment targets for blood glucose, blood pressure, and lipid control. Similarly, when a pay-for-performance incentive was introduced in the United Kingdom, prospective analyses of care did not show improvements in disparities in management and control of diabetes between ethnic groups.^18,19 These data show that even when there is universal access to health care and providers are incentivized to perform various process measures, delivering comprehensive and equitable diabetes care is a complex and multidimensional process.

MISMATCH BETWEEN EXPENDITURES AND DIABETES OUTCOMES

In addition to variation in expenditures across nations, there are differences in diabetes-related outcomes. These differences, however, are more modest, and across the majority of national health systems, despite considerable expenditures, there is a clear and common picture of sub-optimal diabetes-related outcomes. Using data from national health examination surveys in seven countries with mixed income status, the World Health Organization found that more than 70% of individuals with diabetes were not meeting the glycemic targets recommended by the IDF.²⁰ Recent economic instabilities may further complicate the status of diabetes and chronic disease care and achievement of these targets. In Europe, for example, 17 of the 28 European Union countries have recently decreased health care spending as part of austerity measures intended to stabilize local and regional economies.¹⁷ In Brazil, China, and India, three of the five countries with the highest number of diabetics, HbA1c goals are met less than half of the time.^20,21 Achievement of target glycemic, lipid, and blood pressure control in less than half of all diabetics has also been described for the countries of the Middle East and North Africa region. In this region, where diabetes prevalence rates are higher than in any other region of the world, more than 10% of all adults in the region die from diabetes.²² In Africa, where the prevalence of diabetes is expected to double over the next 20 years, when diabetes is diagnosed, patients experience sub-optimal care and outcomes due to: inadequately trained health care personnel; lack of diabetes drugs; poor access to health care facilities and services; distrust or lack of faith in the health care infrastructure when it does exist; limited or no assistance for the cost of drugs and glucose monitoring supplies; and poor or nonexistent diabetes education.^21,23

Over the last 20 years, evidence of declining rates of diabetes complications—including acute myocardial infarction, stroke, amputation, end-stage renal disease, and death from hyperglycemic crises—has emerged. Nevertheless, during this same time period, almost half of US adults with diabetes did not meet recommended goals for diabetes care and, among older adults, certain complications such as end-stage renal disease actually increased.^24,25 The discrepancy between costs and outcomes suggests that there is room for improvement in the way health systems are structured to provide diabetes care. In order to improve diabetes-related outcomes in older adults and to further prevent and reduce diabetes complications, several deficiencies in the health system need to be addressed and corrected.

Among these deficiencies are: inadequate diabetes prevention programs; a limited understanding of how to promote healthy aging; an insufficient evidence base to guide management of complex, heterogeneous comorbidities and complications in older adults; an incomplete understanding of how to engage older adults and caregivers in shared decision-making processes for treatment and care; a shortage in the geriatric and diabetes workforce needed to meet the needs of this large population; and disparities in care for individuals in different ethnic and social groups. We next review the current state of care in these areas, propose a conceptual model of comprehensive diabetes care in older adults (Fig. 2), and discuss existing and recommended policy initiatives for achieving this model of care.

FIGURE 2.

Conceptual Model of Comprehensive Diabetes Care in Older Adults

DIABETES PREVENTION

It is estimated that one out of every two older adults in the United States has prediabetes, placing them at high risk for developing the disease.⁵ In the Cardiovascular Health Study, a large prospective study assessing the association of lifestyle factors with incident diabetes in adults older than 65, 90% of new cases of diabetes appeared to be attributable to lifestyle factors, including physical activity, diet, body mass index, alcohol use, and tobacco intake.²⁶ Given these data, primary prevention seems to be among the most enticing and potentially beneficial places to intervene to curb the growing prevalence of the disease. Despite the aging and increasingly overweight and obese population, over the last two decades, strong evidence has emerged that for individuals at high risk for developing diabetes, such as those with prediabetes, impaired fasting glucose, or impaired glucose tolerance, intensive lifestyle interventions can prevent or delay progression to diabetes.⁵ Not only are older adults subject to developing diabetes from the various lifestyle risk factors, but they have also been shown to benefit from the targeted lifestyle intervention programs that have been studied. Indeed, sub-group analysis of the Diabetes Prevention Program (DPP) group by age showed that lifestyle modifications were most effective in preventing diabetes in older individuals.²⁷ Of note, sub-group analysis also showed no significant difference in response rates to intensive lifestyle and pharmacologic interventions among members of different ethnic groups including white, African American, Hispanic, American Indian, and Asian.²⁸

These interventions, which include weight loss of at least 5%–7% of starting body weight, reduced calorie diets high in fruit, vegetables, and fiber, and moderate physical activity, have been shown to be more effective than any other type of preventive intervention such as pharmacotherapy, which does not seem to be as effective in diabetes prevention as in younger adults.^29-31 Three studies in particular, the Chinese Da Qing Study, the Finnish Diabetes Prevention Study, and the US Diabetes Prevention Program Outcomes Study, have demonstrated that especially with follow-up counseling, these interventions can provide sustained effects in reducing the rates of conversion to type 2 diabetes over many years.³⁰ Unfortunately, there is a paucity of large clinical trials for drug and lifestyle interventions for primary and secondary prevention in low- and middle-income countries. Nevertheless, it is anticipated that these interventions may yield similar outcomes to those seen in high-income countries.^32,33

A number of new policy initiatives in the United States have important implications for the prevention and management of diabetes. The most prominent has been the Patient Protection and Affordable Care Act (ACA), which was passed in 2010.³⁴ Several key provisions of this comprehensive legislation apply to primary and secondary prevention in diabetic patients. To reduce financial barriers to receiving preventive care, the ACA now requires most private health plans to provide coverage for an extensive range of preventive services at no cost to the policy holder. These services include those rated as A (strongly recommended) or B (recommended) by the US Preventive Services Task Force and immunizations recommended by the Advisory Committee on Immunization Practices. Relevant examples include blood pressure, cholesterol, diet, diabetes, and obesity screenings; aspirin use; nutrition and tobacco cessation counseling; and depression screening and counseling. Earlier detection of diabetes, through expanded screening and prevention effects, has the potential to promote early and frequent lifestyle counseling and lead to prompt medical therapy, which can have lasting vascular and health benefits for individuals who are diabetic. Large clinical trials have shown that early intensive glucose control starting at the time of diagnosis leads to a legacy effect, resulting in a continuing reduction in rates of microvascular complications, myocardial infarctions, and death from any cause.³⁵

The ACA also established the Prevention and Public Health Fund to provide a sustained funding source for broad preventive and public health efforts and the National Diabetes Prevention Program (NDPP). The NDPP, which consists of collaborations between government agencies, private insurers, and community organizations such as the YMCA, is intended to make evidence-based lifestyle intervention programs for diabetes prevention accessible to individuals through local community-based programs. There is evidence that group delivery of the NDPP intervention in community settings may be significantly less expensive but result in similar outcomes.³⁰ The American Diabetes Association (ADA) has endorsed the NDPP and, as a legislative priority, has recommended funding related programs for elderly at risk for new diabetes.

Despite the evidence for diabetes prevention programs, efforts to increase funding have been challenged. For example, while the 2010 ACA legislation initially appropriated 15 billion USD over ten years for the Prevention and Public Health Fund, this funding was cut in 2012 by more than one third in order to offset other expenditures. We have focused much attention on the significant expenditures imposed by diagnosed diabetes and its related complications, but economic analyses have also shown staggering rises in the cost of prediabetes and undiagnosed diabetes. From 2007 to 2012, in the United Sates, the cost of prediabetes increased by 74% to 44 billion USD and undiagnosed diabetes by 82% to 33 billion USD.³⁶ Given the substantial health and economic burden associated with prediabetes, diabetes, and associated comorbidities and the growing aging population, legislators and policy makers have a responsibility to provide the appropriate resources to support diabetes prevention programs.

MANAGING THE BURDEN OF DIABETES COMPLICATIONS

When diabetes occurs in older adults, reducing micro- and macrovascular complications and other comorbidities such as depression, cognitive decline, and frailty become the next most effective step in improving diabetes outcomes. Guidelines to help providers navigate the unique challenges of managing diabetes in this population have been developed by both the ADA and the IDF.^5,13 Landmark epidemiologic and pharmacologic diabetes research trials, which are used to guide management recommendations, have often excluded older adults. Therefore, extrapolation of the existing evidence base is not always feasible or appropriate for older diabetics who require more individualized care. Recognizing these challenges, both the ADA and the IDF have recommended stratification of older diabetic patients by health and functional status. The ADA uses patient characteristics and health status to stratify older diabetics as being healthy, complex/intermediate, and very complex/poor health, whereas the IDF utilizes three categories, including functionally independent, functionally dependent with either frailty or dementia, and end-of-life care. Though both groups provide expert recommendations on individualizing therapeutic goals based upon the patient’s overall health and functional status, they also acknowledge that there is insufficient data on how to best accomplish this in older adults. Nevertheless, there are broad therapeutic goals that should be used. For example, whereas strict glycemic control targets are often used to prevent long-term microvascular and cardiovascular complications in younger adults with briefer duration of diabetes and fewer comorbidities, older adults with shorter life expectancies and higher risk of hypoglycemia generally require more liberalized targets. In these individuals, mortality benefits more often accrue by preventing extremes of glycemic excursions.

Many existing health systems, which are designed to treat acute illnesses through brief and fragmented care episodes, are poorly equipped to handle the complexities of managing older individuals with many comorbidities. In addition to the cardiovascular and renal complications of diabetes, older diabetic adults are often at an elevated fall risk and have vision or hearing impairment, depression, cognitive impairment, and potentially more social isolation than their younger counterparts. In older adults with more complex and heterogeneous health states, addressing these many conditions—including the relevant history, physical, labs, and social context—in a brief health encounter is often not feasible. Many of these conditions require treatment with multiple medications and, in addition to the burden and financial cost of taking so many medications, these individuals are at risk for adverse drug effects and interactions. Among the most concerning of these effects is hypoglycemia, which is more prevalent in older adults than in younger adults.⁵ Several mechanisms such as alterations in pharmacokinetics, including reduced drug clearance by renal and hepatic impairment, pharmacodynamics, and increased hypoglycemia unawareness all contribute to potentially severe hypoglycemic episodes.³⁷ Alarmingly, in a retrospective analysis of recent national trends in US hospital admissions for hyperglycemia and hypoglycemia among Medicare beneficiaries, older adults, particularly those aged 75 and older, had high rates of admission for hypoglycemia, with the frequency of admissions for hypoglycemia actually exceeding those for high glucose levels.³⁸

THE ROLE OF PATIENT AND THE CAREGIVER IN DIABETES CARE

Given the remarkable heterogeneity in the health and functional status of individual older adults and the paucity of evidence to guide their medical management, engaging older adults and their caregivers in informed medical decision making is critically important. Research has demonstrated that older patients prefer to be members of a shared decision-making team, and when such an effective patient–provider relationship is formed, patients are more likely to adhere to treatment recommendations.^39-41 This is especially important when quality of life is addressed and framed according to the patient’s individual wishes during consideration of intensive treatment regimens. As older adults with diabetes develop complications and functional impairments, care partners, including family, friends, or other caregivers, become increasingly important in managing or comanaging the patient’s diabetes, and their involvement increases the likelihood of successful self-care behaviors.⁵

Health care providers have generally not been reimbursed for the time it takes to discuss the social contexts contributing to patients’ health or for palliative and end-of-life care—issues that become increasingly important with advancing age. In the setting of such complex disease states, multidisciplinary teams consisting of primary care physicians or diabetes specialists, diabetes educators and dietitians, ophthalmologists, podiatrists, and behavioral specialists are necessary. Unfortunately, most diabetes care systems are more fragmented. The Diabetes, Attitudes, Wishes, and Needs study was a cross-sectional international survey of randomly selected diabetic patients, physicians, and nurses that sought to identify the attitudes, wishes, and needs of the above groups. The survey addressed several areas in diabetes care, including self-management behaviors, diabetes-related distress, the quality of relationships between providers and patients, provider collaboration, and barriers to the effective use of medication therapy, and found that the majority of patients did not receive care through multidisciplinary provider teams.⁴²

HEALTH DELIVERY SYSTEMS FOR DIABETES MANAGEMENT

Perhaps the most notable provision of the ACA is the broad extension of insurance coverage through Medicaid expansion and the creation of health insurance exchanges, which have significantly reduced the number of Americans without health insurance coverage. Although more than 90% of older adults were already insured by Medicare and therefore do not benefit from insurance coverage expansion, it is hoped that the ACA, by expanding health access to younger and middle-aged adults who previously lacked coverage, will lead to reductions in diabetes complications for the next generation of older adults.⁴³ In 2008, for example, expansion of Medicaid coverage in Oregon led to an increase in the use of health care services, reduced individual financial strain, and improved rates of diabetes diagnosis and management.⁴⁴

Improving preventive efforts and access to care is a significant first step in ameliorating the burden of diabetes in older adults. Because diabetes is a complex disease, with a clinical trajectory that is affected by biological, sociological, psychological, economic, and cultural factors, controlling the disease and preventing complications is often more challenging than simply modifying any one factor. For example, within the Veterans Affairs population—a population where insurance coverage is high and copays are low—among more than 80,000 diabetic patients, only 36%, 41%, and 23% achieved control of HbA1c, low-density lipoprotein, and blood pressure, respectively. Further, only 4% of these patients achieved simultaneous control of all three intermediate health outcomes.⁴⁵ Improving health outcomes for a disease with so many contributing factors requires a multipronged approach, where the interplay of patient, provider, and health system factors synergize to address the multiple determinants of the disease course.

Research from the last two decades has shown that various initiatives such as the chronic care model and adaptations for implementing the chronic care model, such as the patient-centered medical home, are needed to provide comprehensive and coordinated care that empowers patients to manage their disease.^46,47 Recognizing that existing health care systems are fragmented, these models include: an emphasis on preventive, proactive disease management; recommendations for integration of care across different health care settings and providers; incorporation of up-to-date evidence-based guidelines into clinical practice with disease registries and electronic health records; patient empowerment through disease self-management education; greater emphasis on incorporation of psychosocial and cultural determinants of care; and leadership and policies promoting initiatives to improve outcomes and providing the resources needed to do so. In European countries, there is evidence that the patient-centered medical home model may also be applicable and fill important gaps in chronic disease management, especially when it comes to shared decision making, self-management support, and coordination of care and communication between care providers.⁴⁸

For patients with diabetes, hospitalizations are sometimes an inevitable part of the disease process and an important link in the diabetes health care delivery chain. One third of diabetic patients will be hospitalized two or more times in a given year.⁴⁹ Transition from inpatient to outpatient care represents a critical point in the care process where potential disruptions in care can occur. These disruptions can lead to adverse outcomes, which may include readmission to the hospital. For diabetic adults over the age of 65 admitted with diabetes complications, one in five will be readmitted within 30 days.⁵⁰ The ACA includes a number of provisions intended to reduce hospital readmissions. The Community-Based Care Transitions Program evaluates models for improving care transitions between the hospital and other settings and reducing readmissions for high-risk Medicare patients. Another program created by the ACA is the Independence at Home Demonstration Program (IAHP), which enables primary care providers including physicians and nurse practitioners to provide comprehensive, home-based care for home-bound chronically ill Medicare patients. The IAHP is also testing payment models whereby some of the cost savings accrued by the program will be redistributed to health care providers meeting various quality measures and reducing expenditures. The final element aimed at reducing readmissions is the Hospital Re-admission Reduction Program, which penalizes hospital organizations for excess 30-day readmissions by reducing their Medicare base reimbursements for inpatient services.⁵¹

Similarly, older adults may transition to skilled nursing or long-term care facilities, where at least one quarter of residents are diabetic.⁵² These individuals are at an increased risk for hypoglycemia and other complications, including hyperglycemia, depression, falls, infections, and foot wounds.³⁰ Residents in long-term care facilities often have poor nutritional status and may be volume depleted, both contributing to higher rates of glycemic variability. To date, policies, including the ACA, have not provided adequate support for the many facets of providing comprehensive diabetes care in these settings. Future support for equipping these facilities with appropriately trained health care providers and implementing diabetes-related protocols for managing medications and hypo- or hyperglycemia are crucial to providing care for this important sub-population of older adults. Additionally, for chronically ill, home-bound older adults, more programs enabling home health care and visits such as the IAHP may help reduce complications and prevent hospitalizations.

To support these programs and meet the needs of the older diabetic population, there will need to be a substantial increase in trained diabetes providers. Across the globe, there is a critical shortage of health care providers to meet the needs of adults with chronic diseases such as diabetes.⁵³ This shortage is especially noticeable for older adults. In a survey of older adults in 11 countries, in every country but Canada, more than half of those surveyed reported they could not get same- or next-day appointments to see a provider when they were sick.¹¹ To meet the needs of the older population in the United States, it is estimated that there will need to be 30,000 geriatricians, nearly four times the number available today.⁵⁴ Additionally, less than 1% of nurses and 3% of mid-level health care providers in the United States are certified in geriatrics, and only 3%–4% of psychologists and social workers devote the majority of their practices to the care of older adults. In addition to efforts to improve access and quality of care while reducing costs, the ACA includes provisions designed to address the geriatric and diabetes workforce shortages.⁵⁵ Several grants will enable new geriatric education centers to train health care providers in geriatric and chronic disease care and promote faculty recruitment into academic geriatric programs. There will also be expanded federal training programs to encourage individuals to pursue advanced degrees in geriatric nursing, long-term care, and geriatric psychology. Finally, it establishes programs to provide education to family caregivers and direct caregivers, who are critical links in improving the health care of some older adults. Even with these programs, it is likely that there will still not be enough geriatric, primary care, and diabetes physicians to treat the growing diabetic population. This is also true in low- and middle-income countries, which often already face a shortage of physicians. In this setting, alternative delivery models will be needed to provide diabetes care and may include highly trained mid-level and other diabetes care providers, including educators, nutritionists, pharmacists, and lay diabetes champions who can provide diabetes self-management education.

One model that has been proposed to improve access to diabetes care is the shared medical appointment (SMA), or group visit. Over the last decade, there has been growing evidence that patients receiving care in group visits benefit from peer-to-peer support, increased time for education and counseling, increased performance of evidence-based processes of care and adherence to guidelines, improved health outcomes, and higher patient satisfaction.^56,57 In older adults without significant cognitive decline or functional limitations, group visits can also facilitate improved care coordination and efficiency if multiple providers are able to see the patient and address different needs such as medication issues, self-management support, lifestyle and behavioral counseling, and ophthalmologic and foot evaluations in the same visit. The Veterans Affairs has adopted the SMA as part of its outpatient model for the patient-centered medical home.⁵⁸ Despite several studies describing the utilization of this delivery model in diabetes care, there has been significant heterogeneity in the way these visits are designed, which health services are offered within these appointments, and the health outcomes, health care utilization, and cost-effectiveness resulting from the SMA. A recently published systematic review of shared medical appointments in diabetes care included 17 studies comparing SMAs with usual or enhanced usual care.⁵⁹ Of these, 13 were randomized controlled trials. This analysis showed that SMAs resulted in a statistically significant decline in HbA1c by ~0.6 percentage points and in systolic blood pressure by ~5 mmHg. The authors note that there was too little evidence and too much variability to appreciate the effects on health care utilization and costs, treatment adherence, and patient and staff satisfaction. They concluded, “Our evidence synthesis uncovered far more gaps in the literature than it found in definitive results. The most important of these gaps is likely the heterogeneity of what comprises ‘diabetes SMAs.’”⁵⁹ This model holds promise in broadening access to care, improving intermediate diabetes health outcomes, patient and provider satisfaction, and cost-effectiveness of diabetes care delivery. Nevertheless, optimizing the efficacy of this delivery model will require funding support for large, multicenter, randomized clinical trials, in order to study standardized approaches to this care delivery model.

As a complement to these models of health care delivery, which aim to improve the way chronic conditions like diabetes are managed, the ACA has provisions for the exploration and implementation of alternative payment models. These payment mechanisms reimburse providers for the quality and comprehensiveness of care provided rather than per unit of service delivered. Public and private payers are experimenting and implementing bundled payments, for example, that enable organizations to participate in payment agreements centered on disease-specific episodes of care. Within these arrangements, health care providers and organizations are held accountable for the comprehensive cost and quality of care provided for a disease process. It is thought that bundling will promote close collaboration and coordination across different health care settings and providers who are otherwise more fragmented. In The Netherlands, where a bundled payment program for diabetes management has been in place for several years, preliminary data show that though reimbursements to providers vary significantly and upfront costs may be high, care delivery processes and transparency of care have improved.^60,61

A separate payment mechanism, the Accountable Care Organization (ACO), unites groups of physicians, health care providers, and hospitals into a virtual coordinated care network in the United States. Members of the ACO accept shared responsibility and incentive for reducing the cost and improving the quality of care provided to a given group of patients.⁶² In this model, savings that are generated by the ACO are shared with the payer. The ACO receives shared savings only if it can meet standards of quality of care in four areas: patient/caregiver care experiences, care coordination and patient safety, preventive health, and at-risk population health, including diabetes and cardiovascular disease. It is estimated that ACOs participating in the Medicare Shared Savings Program, established by the ACA, will generate savings of up to 940 million USD within the first four years.⁶³

FUTURE DIRECTIONS: CLOSING THE EVIDENCE GAP

Given the substantial domestic and international health and economic burdens imposed by diabetes in older adults, it is prudent to invest in research on improving diabetes prevention and care in this population. In the United States, in addition to expanding the National Diabetes Prevention Program, federal efforts should include appropriate allocation of financial support for the initiatives of the National Institute of Diabetes and Digestive and Kidney Diseases and the Center for Disease Control’s Division of Diabetes Translation. This will support translational and clinical research that may enable a better understanding of how metabolic conditions like diabetes and obesity, which are associated with aging, can be prevented and what conditions are needed for individuals to age healthy. Many large clinical trials have shown the benefits of lifestyle and pharmacotherapy interventions in preventing diabetes. For the current population of older adults, however, these prevention trials have historically not enrolled individuals with functional and cognitive impairment and individuals older than 70 years, thereby excluding a significant sub-group of older adults.

Though the ADA and IDF have established guidelines for caring for older adults with diabetes, studies show that the majority of clinical practice guidelines (CPGs) do not address applicability of guidelines to older adults with multiple comorbidities, nor do they sufficiently incorporate patient preferences. In one review of clinical practice guidelines, the authors wrote,

Basing standards for quality of care and pay for performance on existing CPGs could lead to inappropriate judgment of the care provided to older individuals with complex comorbidities and could create perverse incentives that emphasize the wrong aspects of care for this population and diminish the quality of their care.⁶⁴

Internationally, in collaboration with national health ministries or diabetes associations, many non-Western countries have developed guidelines for diabetes management. These are often based, in part, on the above guidelines. These guidelines have the potential to improve care by standardizing various process measures required to address the disease; however, they may not address the needs of local populations and different cultures and need to be adapted accordingly.⁶⁵ Local guidelines also need to be updated frequently, to match recent revisions in the evidence base for diabetes care. When guidelines are adapted to the needs of the targeted populations, local and national policies must ensure the provision of workforce, supplies and medications, and support systems to implement the recommendations.

Future trials on lifestyle and pharmacological therapies must seek to actively enroll older and sicker patients. Without directly available evidence, we are left with numerous uncertainties in prevention and management of diabetes in older adults. For example, it is unclear how we should approach weight management in the elderly. Intentional weight loss may lead to loss of muscle and bone and increase the risk of frailty.⁶⁶ The need for research in older adults with diabetes also includes the evaluations of nonpharmacological interventions, such as bariatric surgery, and the new self-management devices, such as continuous glucose monitors.

The emphasis on diabetes prevention in middle-aged adults must be underscored, because it will enable the next generation of older adults to live with a significantly reduced diabetes burden. In addition to diabetes prevention programs that we have described above, ongoing clinical trials are underway, such as the Restoring Insulin Secretion Adult Medication Study—a clinical trial evaluating whether aggressive glucose lowering with pharmaco-therapies in adults with prediabetes and early type 2 diabetes will lead to sustained improvements in beta (insulin-producing) cell function after the medications are stopped.⁶⁷ These studies will provide insight on how to enable sustained diabetes prevention in high-risk individuals.

Moving forward, international and US reform efforts should emphasize the need for primary prevention and provide the necessary financial support for creating comprehensive programs necessary for long-term diabetes prevention. In Australia, for example, the Australian lifestyle intervention program, Life!, which entails a behavioral change intervention of six group sessions over eight months, has exemplified an effective collaboration between policy makers and health care providers. Initial results were notable for a significant weight loss of 2.7% of starting body weight among participants over this eight month time period.⁶⁸ A lack of funding has limited the investigators from obtaining follow-up data; therefore, it is not clear whether these results will be sustained. This highlights the need for providing continued funding support for prevention programs. Few countries have attempted to adopt large-scale diabetes prevention programs, and further evidence on strategies for implementing these programs at the national level will better enable cross-national adaptation of these programs.^68,69

For health care providers caring for older adults with diabetes, assessment of an individual’s risk of diabetes or duration of diabetes, their anticipated life expectancy, and functional status is critical to optimizing care of the patient. Just as quality measures for glycemic control, blood pressure, and lipid management are widely used for diabetes management, quality metrics for individualized therapy in older adults should be devised and considered, and health care providers should be appropriately reimbursed for the time it takes to provide such comprehensive care. Each visit should include assessment for any new comorbidities, cognitive and physical function, mood changes, whether or not vision/hearing impairment is present, nutrition status, fall risk, medication review with de-prescribing when possible, ability for disease self-management, and need for caregiver support. This level of comprehensive care requires coordinated, multidisciplinary care teams to provide care that is not fragmented and more likely to result in better clinical outcomes and patient satisfaction. Innovations in the care delivery system, such as shared medical appointments, need to be systematically evaluated with regards to their impact on diabetes care for older adults.

Older adults, when able, should be shared decision makers, and before any new treatment is proposed, its potential effects on quality of life should be addressed with the patient. Research into how best to engage older adults and care partners in health care decision making may help to improve patient satisfaction and health care–related quality of life. Novel systems for delivering health care in settings such as shared medical appointments and other quality improvement initiatives should also aim to be culturally tailored to focus on reducing racial and ethnic disparities and improving outcomes in these populations. Evidence has shown that culturally tailored programs result in larger improvements in intermediate health outcomes such as HbA1c than from general quality improvement interventions.⁷⁰

There are many additional research questions for investigators working on improving diabetes care in older adults. In combination with translational studies on how diabetes pathophysiology evolves with aging, more research on biologic and social predictors of new diabetes in older adults is needed. The historical exclusion of older, sicker patients from randomized controlled trials of diabetes treatments needs to be rectified. We commend clinical trials such as the Glycemia Reduction Approaches in Diabetes comparative effectiveness trial that are actively including older patients. The increased inclusiveness of randomized controlled trials needs to be coupled with observational studies of real-world clinical populations of older adults with diabetes who may still be excluded due to clinical and ethical concerns. For example, it may never be feasible to conduct randomized controlled trials of glucose-lowering therapies with older patients with frank dementia. These trials and observational studies also need to be accompanied by health economic evaluations in order to understand the policy implications of new findings.

CONCLUSION

Diabetes is imposing a significant morbidity, mortality, and economic burden on older adults. Its prevalence continues to rise, and a critical proportion of older adults is at risk for, or already has, the disease. When older adults do get diabetes, it frequently occurs in the setting of extensive cardiovascular, functional, and physical comorbidities, which further complicate disease management. Individualized, coordinated, multidisciplinary, patient-centered care is needed to optimize diabetes management and reduce complications of the disease. In order to curtail the health and economic threats posed by the disease, collaborative efforts between clinicians and other health care providers, researchers, public health organizations, development agencies, policy makers, and other funding sources must occur. These organizations should work together to ensure expansion of the health care workforce trained to manage the geriatric population and diabetes and to broaden access to the basic pharmacotherapies and supplies needed to manage the disease. Consistent development and application of evidence-based guidelines, addressing the heterogeneous needs of individual patients and that can be tailored to local populations, should be used to ensure that the highest quality of diabetes care processes are followed. Following these processes alone will not be enough to improve clinical outcomes. Older individuals will need access to lifestyle counseling and pharmacotherapies needed to prevent diabetes and complications. Multidisciplinary teams of health care providers trained in diabetes, nutrition and exercise counseling, eye and foot care specialists, and psychosocial care are an imperative to addressing the challenges of the disease. Finally, therapeutic decisions will need to be made through a shared decision process involving older adults and their care partners. Health care delivery systems will need to become increasingly adaptable and more efficient at meeting the needs of this chronic disease, which poses a significant burden on older adults.