The complex web of health: relationships among chronic conditions, disability, and health services

Objectives

A critical issue in health-care reform concerns how to realign health-care delivery systems to manage medical care services for people with ongoing and costly needs for care. We examined the overlapping health-care needs of two such population groups among the U.S. working-age population (those aged 18–64 years): people with chronic medical conditions and people with disabilities.

Methods

Using the Medical Expenditure Panel Survey (2002–2004), we examined differences in health status, service use, and access to care among and between working-age adults reporting disabilities and/or one or more chronic conditions. We also analyzed people with three key chronic conditions: arthritis, diabetes, and depression.

Results

More than half of working-age people with disabilities reported having more than one chronic condition. Among those with activities of daily living or instrumental activities of daily living limitations, 35% reported four or more chronic conditions at a time. We found considerable variability in access problems and service use depending on how we accounted for the overlap of multiple conditions among people with arthritis, diabetes, and depression. However, disability consistently predicted higher emergency department use, higher hospitalization rates, and greater access problems.

Conclusions

The overall prevalence of chronic conditions among the U.S. working-age population, coupled with the high concentration of multiple chronic conditions among those with disabilities, underscores the importance of reforming health-care delivery systems to provide person-centered care over time. New policy-relevant measures that transcend diagnosis are required to track the ongoing needs for health services that these populations present.As the United States considers dramatic changes in the way its health-care delivery system is organized, two groups merit particular attention: individuals with disabilities and individuals with chronic health conditions. At a time when health-care costs are escalating at an unsustainable pace, both groups consume health-care services at a disproportionately high rate^1–6 while also experiencing less than optimal health outcomes.^7–9 Furthermore, health-care resources are not equitably distributed,¹⁰ calling for substantive changes in the way in which services are provided.The health of people with disabilities gained additional visibility on the national health agenda via the Healthy People 2010 objectives¹¹ and the Surgeon General''s Call to Action to Improve the Health and Wellness of Persons with Disabilities.¹² At the same time, the growing number of adults with chronic conditions has led to a proliferation of disease management programs,^13–17 as well as a substantial body of research describing chronic disease, its consequences, and associated responses.^1,2,9,18,19 What remains less articulated in the scientific literature is that these are actually overlapping groups. While adults with disabilities are likely to have multiple chronic conditions, adults with chronic conditions are likely to develop limitations in functioning or participation, particularly as conditions accumulate over time. In this study, we directly analyzed this overlap, with a focus on health, access to care, and service use in the U.S.Previous research shows that a substantial number of adults have multiple chronic conditions and may also have limitations in activities or functioning. For instance, in 1997, nearly 25% of Medicare beneficiaries had limitations in activities of daily living (ADLs).³ Within this group, the prevalence of cancer, stroke, diabetes, and rheumatoid arthritis was each more than 20%, and the prevalence of hypertension and osteoarthritis was higher than 50%. Treatment of these conditions required up to one health-care visit a week, and these individuals were twice as likely to be dissatisfied with the coordination of their care.²⁰Whether one considers the new medical home initiatives,²¹ obesity reduction,²² disease self-management,²³ prevention of secondary conditions among people with disabilities,²⁴ or any number of further priority items on the nation''s public health agenda,²⁵ there remains a pressing need to quantify the extent of comorbidity in the U.S. population and to clarify its associations with disability. About half of all Americans have at least one chronic condition, and given that roughly half of those individuals actually have more than one such condition at a time, the pursuit of these agenda items may be hampered if approached only one disease at a time.² Furthermore, when individuals accrue limitations in how they function or the activities they can do, additional interventions may be required to assure their access to health-care services, to coordinate the providers involved in their care, or to craft treatment regimens that accommodate their functional needs.²⁶To build upon the existing literature, we analyzed a nationally representative sample of working-age Americans, clarifying the way in which health, access to care, and service use is impacted by a single chronic condition vs. multiple chronic conditions, with or without self-reported disability limitations. As exemplars, we also examined three conditions in greater detail: arthritis, diabetes, and depression. Among the most highly prevalent chronic conditions in the U.S., these three conditions were selected because they potentially result in a wide range of health and functional impacts across different body systems, are accompanied by differing constellations of comorbid conditions, and may require care from providers in differing specialties or settings.^27–29 Thus, we examined the relative contributions of a single primary diagnosis, multiple comorbidities, and disability limitations to several key health-care measures, including access to care, ambulatory visits, hospitalizations, and emergency department (ED) use.While substantial health services research has been conducted on the impact of chronic conditions on older Americans^3,30,31 and children,^32–34 less is known about these phenomena among the working-aged, particularly for people with disabilities. Additionally, the impact of chronic conditions and disability on major life activities, such as school or work, necessarily varies with life course stage. Given the large size of the working-age population, additional concerns regarding their insurance coverage, and their distinct role expectations relative to older adults or children, we limited our analysis to people aged 18–64 years.