Health Insurance Coverage Among People With and Without Diabetes in the U.S. Adult Population

CONCLUSIONS

Health insurance coverage among people with diabetes compared with coverage for people without diabetes has not been examined in national data for a couple of decades. We found that nearly all diabetic and nondiabetic adults ≥65 years of age had health insurance, mainly attributable to having Medicare benefits. Although the majority of adults 18–64 years of age had health insurance coverage, a significant proportion was uninsured (15% of those with diabetes and 22% of those without). This represented ∼2 million adults 18–64 years of age with diabetes who were not insured, ∼5% of the total uninsured population in the U.S. (1). This is a large public health concern given that the diabetic population needs routine care to prevent serious diabetes-related complications.

The financial burden of diabetes both to society and to the individuals with diabetes is substantial. Significantly more adults 18–64 years of age with diabetes had Medicare, Medicaid, or other public insurance compared with their counterparts without diabetes, putting a strain on government-funded insurance mechanisms (7). Although almost all diabetic adults ≥65 years of age had Medicare, most supplemented Medicare with private insurance, which may be a financial burden, especially for those with limited income. Thus, although the majority of people with diabetes have health insurance coverage, a large proportion apparently lacks adequate coverage, requiring supplemental insurance to obtain additional preventive and maintenance health services.

Several changes in health insurance coverage have occurred over the past two decades. Although the proportion of diabetic individuals with health insurance coverage was similar in 1989 (92%) (5) and 2009 (90%, herein), the absolute number of people with diabetes who were uninsured rose over threefold, from 600,000 to 2.02 million. With no improvement in the rate of health insurance coverage among diabetic individuals and the rise in the prevalence of diabetes, the burden of diabetes in terms of costs to society has significantly increased over this 20-year period. Second, although the proportion of people with health insurance coverage remained higher over time for people with diabetes, the gap in the proportion covered between people with and without diabetes increased from 5% in 1989 to 9% in 2009; people with diabetes had greater coverage relative to people without diabetes in 2009. People without diabetes may forego insurance because of rising costs, particularly if they are healthy and believe insurance is unnecessary. In addition, adults <65 years of age with diabetes are entitled to Medicare coverage if they have a long-term disability, including end-stage renal disease, which may offset the effect of increasing insurance costs for people with diabetes. Third, the proportion of diabetic adults <65 years of age with Medicare coverage increased from 10 to 14% between 1989 and 2009. In addition, the proportion with private insurance decreased for diabetic individuals of all ages (18–64 years of age, from 69 to 58% between 1989 and 2009; ≥65 years of age, from 69 to 51% between 1989 and 2009). The decrease in private health insurance may be related to rising health insurance costs, greater unemployment over the past decade, and more people living under the poverty threshold. Finally, the most common types of private health insurance plans shifted from fee-for-service plans to PPO plans. In the 1980s and 1990s, health insurance costs increased considerably, and the majority of employer-sponsored fee-for-service plans were replaced with less expensive managed care plans.

Our results corroborate previous studies indicating that lack of health insurance coverage is a major barrier to health care access that could, consequently, have detrimental health effects in people with diabetes (2–4). Regardless of diabetes status, seeing a doctor for general care, an eye doctor, or a foot doctor in the past year was more common for those with health insurance. People with hypertension or a heart condition were also more likely to have health insurance; coverage may encourage people to schedule regular medical visits, which provides more opportunities for diagnosis. A study among underserved diabetic patients receiving care at Federally Qualified Health Centers, where care is provided regardless of insurance status, indicated that those with continuous health insurance were more likely to receive LDL testing, a flu vaccine, and/or nephropathy screening (8). In addition, patients who had partial insurance coverage in the past 3 years, regardless of the amount of time insured, were less likely to receive preventive care (9). We also found that health insurance coverage was lower in minorities and people with less education and income. Efforts should focus on increasing health insurance coverage for underserved populations who are often at the highest risk for diabetes complications (10,11).

Two primary reasons were stated for U.S. adults <65 years of age not having health insurance coverage. First, high cost was the most common reason for no insurance, a finding supported in previous literature (3). We found that few adults with private insurance had low income, regardless of diabetes status. Among people with private insurance, only 4% of adults had family incomes below the poverty threshold, whereas the majority (68% with diabetes and 71% without diabetes) had incomes well above the poverty threshold (poverty income ratio ≥3.0, a yearly income of ≥$66,000 for a family of four). Furthermore, the proportion of income spent on private insurance premiums and family medical care was higher for low-income people, a result supported in previous work (12). Second, unemployment has significantly increased over the past decade, leaving many without the means to pay for insurance (13). Indeed, we found that job loss or change in employers was the second most common reason reported for not having insurance.

Medical expenses for people with diabetes are estimated to be 2.5 times higher than those for people without diabetes (10). The direct costs of diabetes were estimated to be $116 billion in 2007 (14). The 2010 health care reform bill would help cover the majority of the 2 million U.S. adults with diabetes who are uninsured (15). However, it remains to be seen whether these policies would adequately cover diabetic individuals’ medical needs and whether insurance premiums would be affordable for all patients. As part of health care reform, the Pre-existing Condition Insurance Plan would cover people with diabetes who have been uninsured for the past 6 months, with costs varying depending on state of residence, age, and plan type.

A major strength of our study is the use of national data, which allows generalization to the U.S. adult noninstitutionalized population. A limitation is that we could not distinguish between type 1 and type 2 diabetes. Nevertheless, we assessed insurance coverage by glycemic medication use and found some differences in coverage for people who were on insulin compared with those who were taking oral or no medications. We could not distinguish people with undiagnosed diabetes. Previous work has shown that people with undiagnosed diabetes have a higher uninsured rate than people with diagnosed diabetes; thus, the percentage with health insurance coverage may be underestimated in this study (16). Our analysis included participants who reported prediabetes and use of insulin (n = 4) or oral medication use (n = 78). It is likely that the participants taking oral medications are using them to lose weight and/or prevent diabetes. Although it is less clear whether the data are valid for the prediabetic individuals reporting insulin use, the inclusion of these participants would not impact the estimates. Finally, we were only able to determine the proportion of people with prescription coverage among those with Medicare or private insurance; the proportion of people with dental coverage could only be determined for those with private insurance. In addition, we could not examine the extent of dental and prescription coverage.

In the past 20 years, major scientific advancements have established that achieving and maintaining glucose control as early as possible significantly reduces the onset and progression of diabetes complications (17,18); furthermore, long-term follow-up has shown that glucose control in adults who are at high risk for diabetes is cost-effective (19). In addition, there is evidence that age of diabetes diagnosis, some complications, and mortality have been decreasing over time (20–22). Therefore, with universal coverage of people with diabetes, such as through reformed health care that translates to greater provision of medical care, there is the very real opportunity to reduce the overall burden of diabetes to society.

This study provides baseline information on health insurance coverage and, in the future, could be used to evaluate whether health care reform increases the percentage of people with diabetes who have coverage. Health insurance coverage, combined with diabetes education and public health prevention strategies, is fundamental for reducing diabetes complications, increasing the quality of life for people with diabetes, and reducing the economic burden of diabetes-related medical costs.