RTC Projects: R4 Background

Health is the core foundation that allows people to participate fully in the most important aspects of their lives. Yet, people with disabilities may be the largest underserved and virtually unrecognized subpopulation of Americans that demonstrates evidence of health disparities. In particular, recent research shows that people with disabilities have a greater prevalence and more complex mix of multiple chronic conditions (MCC), also called comorbidities.

The fact that people with disabilities experience a greater number of chronic conditions but have diminished access to health care is especially troubling given that, with the addition of a chronic condition, an individual’s risk for many adverse outcomes increases, including unnecessary hospitalizations, duplicative tests, impaired functional status, adverse drug events, conflicting medical advice and even death.

Moreover, for people with disabilities, each additional chronic condition and/or failure to properly manage existing conditions increases the likelihood that they will require greater assistance with activities of daily living, have to reduce their participation, or need to move out of the community into more restrictive settings.  



In late 2010, the U.S. Department of Health and Human Services (HHS) developed a strategic framework for addressing MCC. One of the four goals of this framework is to “Facilitate research to fill knowledge gaps about, and interventions and systems to benefit, individuals with multiple chronic conditions.” 

In furtherance of this HHS goal and in response to NIDRR’s priority for this center, this project seeks to increase understanding of the relationship between community services – in this case, health care – and socio-demographic, geographic, and disability factors. The requests of these two agencies easily combine to form a common goal of better understanding the barriers and facilitators needed to improve health and community participation for persons with disabilities.

Purpose of the Study

Objectives for this project include, within disability subgroups:

  1. Identify predictors of chronic diseases in the disability sample.
  2. Identify the common combinations of chronic disease.
  3. Conduct exploratory analysis on differences and similarities across common combinations of chronic disease as related to elements of the Andersen behavioral model.

Researchers have documented the prevalence of common comorbidities and the clusterings of these conditions, but have not examined these questions for subgroups of disability. An important next step in disability surveillance research and MCC research is to disaggregate data into subgroups so that we can better identify risk factors for targeted interventions and outcomes.

An additional important next step is to understand the relationship between those with MCC and disparities in access to health care, and their resulting health status.

This study assesses the community service of health care using the Andersen Behavioral Model, which provides the theoretical foundation for these analyses.

The earlier literature review documented that people with disabilities experience a greater prevalence and more complex mix of comorbidities and multiple chronic conditions, in part due to disparities they experience in accessing health care. However, little is understood about the epidemiology of common comorbidities among people with disabilities. This project fills knowledge gaps about and suggests interventions and systems to benefit individuals with disabilities who experience multiple chronic conditions so that they may participate more fully in their communities.  

Anticipated Benefits

The most important product from this this project is that it will advance empirical data in the scientific literature in ways that are necessary to increase our understanding of the relationship between disability and chronic disease. This can then lead to any number of preventive strategies that are more targeted in nature, as well as modification of policies and programs.

In combination with results from the Center's scoping reviews, findings from the MCC study will inform R-7 Developing a Health Promotion Assistance Tool. 

Finally, these results will address one of the four goals in the 2010 HHS strategic framework regarding MCC: "Facilitate research to fill knowledge gaps about, and interventions and systems to benefit, individuals with multiple chronic conditions."

Methods and Hypotheses

This MCC project responds to HHS’s and NIDRR’s priorities and adds to the existing literature first by identifying predictors of comorbidity in the disability subgroups. Second, after determining which predictors are related to instances of comorbidity, specific analyses with the subsample of cases experiencing multiple chronic conditions will be conducted to explore the most common combinations of comorbidity among subgroups of disability. Then, we will investigate differences and similarities between common combinations of comorbidities across socio-demographic and geographic variables, and access to health care services and health status.  

Our primary hypotheses include the following:

  1. Subgroups of disability experience differences in how comorbidities cluster most commonly.
  2. Prevalence rates for common combinations of chronic condition are higher for all subgroups of disability than those with no disability.
  3. Common combinations of chronic conditions among subgroups of disability vary across socio-demographic and geographic factors.
  4. Common combinations of chronic conditions among subgroups of disability report differential access to health care and preventive services.
  5. Common combinations of chronic conditions among subgroups of disability report differential health status.

More Information about the Design of the Research

Sample, Data Collection and Measurement, Data Analysis

Principal Investigator: Amanda Reichard, PhD