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Journal Issue: Children with Disabilities Volume 22 Number 1 Spring 2012

Children with Disabilities: Introducing the Issue
Janet M. Currie Robert Kahn

Themes of the Volume

Out of the research presented in this volume, five broad themes emerge. These themes are related to defining and measuring disability; trends in disability; the growing importance of mental relative to physical health; the importance of families; and the fragmentation of services for children with disabilities.

Defining Disability and Other Measurement Issues
First, it is remarkably difficult to point to a consensus definition of disability. In the opening article of the issue Neal Halfon and Kandyce Larson, both of the University of California–Los Angeles, and Paul Newacheck and Amy Houtrow, both of the University of California–San Francisco, make the case for a definition that highlights the relationship between health, functioning, and the environment. Specifically, the authors propose that a disability be defined as "an environmentally contextualized health-related limitation in a child's existing or emergent capacity to perform developmentally appropriate activities and participate, as desired, in society."

Defining disability as a limitation rather than a health condition per se highlights the social and technological context of the individual. In a world with electric wheelchairs, for example, a child with impaired mobility will be less disabled than he or she would be otherwise. It follows then that home and school environments can shape disability and that new technologies can either mitigate or exacerbate disability, as Paul Wise, of Stanford University, discusses in his article on the role of technology. The definition proposed by Halfon, Houtrow, Larson, and Newacheck also emphasizes that disability exists along a continuum and varies across children's ages and functional domains.

Until now empirical work on the prevalence of childhood disability has been based on a variety of simpler and more concrete definitions. National surveys that collect information about childhood disabilities, for example, generally ask questions about limitations on activities of daily living; they also usually classify children as disabled if they are receiving services for their limitations. Although the logic behind this latter definition is apparent, it can mean that the number of children counted as having disabilities may expand or contract along with the provision of services. In a similarly problematic way, expanding the number of children with disabilities who are covered by insurance may increase the number of children who have been diagnosed with a particular condition without actually changing the number who suffer from the condition. Many studies reviewed by contributors to this volume, such as those discussed in the articles by Liam Delaney, of University College Dublin, and James P. Smith, of RAND, and by Mark Stabile and Sara Allin, both of the University of Toronto, take into account only the presence or absence of specific health conditions, making that alone the measure of disability. Research based on historical data (which analysts use to examine disability over the life course) consists almost entirely of information about the presence or absence of specific conditions. Clearly, there is little uniformity across time periods or studies in the definition of disability.

Beyond the challenge of defining and measuring disability, many of the articles in the volume highlight ancillary measurement issues. For example, Peter Szilagyi, of the University of Rochester, addresses the challenge of comparing how well different children with disabilities are covered by insurance given the tremendous variation in types of insurance policies available. Typically, a researcher exploring insurance and children with disability knows whether an insurance plan is private or public and perhaps whether it involves "managed care." But such a crude characterization reveals little about what it is the plan actually covers.

James Perrin, of Harvard Medical School and Massachusetts General Hospital, highlights the need for improved measures of the quality of medical care. His concerns dovetail with those of Halfon, Houtrow, Larson, and Newacheck in that he emphasizes that quality measures should focus on improvements in a child's functioning and outcomes rather than on physiological measures or processes of care alone. He argues that collaboration across medical sites that treat children for similar conditions can improve the measurement of the quality of care (by, for example, pooling data to yield larger sample sizes) and ultimately the quality of care itself.

How Big Is the Increase in Childhood Disability?
Although differences in definitions and measures may seem arcane, they directly impinge on researchers' ability to address one of the most controversial issues in the field of childhood disability studies—the huge increase in recent years in the number of children who are considered to have a disability. The measured prevalence of disability for children under age eighteen in the National Health Interview Surveys (NHIS) doubled from 3.8 percent in 1981 to 8.0 percent in 2009. Over the past half century, the estimated prevalence of measured childhood activity limitations has increased fourfold.

What to make of this remarkable rise is a second theme of this volume. The sensitivity of these numbers to the way disability is defined is clear from the quite different estimates contained in other surveys. For example, the National Survey of Child Health (NSCH) classifies only 4.3 percent of children as disabled. The NSCH focuses strictly on limitations relative to other children of similar age; its classification system is not based on medical care, activities of daily living, or receipt of special education services. So, for example, the NSCH would not count as disabled children whose well-controlled asthma does not limit their daily activity. By contrast, the NHIS classifies children as disabled if they receive special education services. The higher NHIS numbers may thus be attributable not only to increases in the prevalence of disabilities among children but to increases in the numbers and shares of children receiving special education services over the past four decades (see the article by Laudan Aron, of the National Research Council, and Pamela Loprest, of the Urban Institute).

In sum, researchers' efforts to track trends in disability and understand the meaning of the recent increase in numbers have been seriously complicated by changes over time in definitions of disability, in screening for disability, in services for disability, and in the extent to which particular conditions are considered to be actually disabling. Several researchers whose work is highlighted here see an increasing epidemic of childhood disability that may stem from factors such as increasing exposure to dangerous chemicals (see the article by Stephen Rauch and Bruce Lanphear, both of the Child and Family Research Insitute in Vancouver). Children today, for example, are exposed to many widely used chemicals, such as pesticides and phthalates, which are found in our diet and are thought to be linked with neurological disorders and disruption of the endocrine system. Indeed, most Americans have metabolites of pesticides and phthalates, as well as of DDT and PCBs, in their blood or urine. These researchers argue that chemicals may interact in synergistic ways to create disease and that by the time medical researchers definitively know the mechanisms by which the chemicals do their damage, many children may have been harmed. Other researchers whose work is reviewed in these pages point to the tremendous reduction in infant and child mortality over time, the immunization-linked decrease in the incidence of many disabling diseases, and the reductions in childhood exposure to air pollution, smoking, and lead, and wonder why these improvements are not reflected in disability statistics. The rise of morbid obesity among children also suggests that new disabling conditions can arise over time.

In the absence of consistently collected statistics about the incidence of childhood disability over time, it is difficult to resolve the controversy over how much of the increase in disability reflects changes in the underlying incidence of disabling conditions. Careful research on some specific conditions, such as autism and asthma, does suggest increasing incidence. What this controversy over a fundamental fact about disability highlights is the need for researchers to arrive at a consistent definition of childhood disability so that they can accurately track trends over time.

Mental Health Issues
A third theme that permeates the volume is the growing role of mental health issues in childhood disability. Over the past several decades, the incidence of disability and its underlying health conditions has shifted away from physical disorders toward mental health disorders. In 2008–09, the top five limiting conditions of children were behavioral or developmental. More than one in five parents reporting a child with a disability cited ADHD as an underlying condition; another 19 percent cited other mental, emotional, or behavioral problems. Today ADHD is almost three times more likely than asthma to contribute to childhood disability.

Moreover, both the Delaney and Smith and the Stabile and Allin articles highlight the significant lifetime costs of mental health disorders for children. In fact, mental health disorders in childhood generally have larger impacts than childhood physical health problems in terms of adult health, years of schooling, participation in the labor force, marital status, and family income. Aron and Loprest document the high prevalence of childhood mental illness and neurodevelopmental disorders in educational settings. For example, autism affects 6 percent of all special education students, up from 2 percent over the past decade. Emotional disturbances affect 6 percent of special education students as well.

The Importance of Families
A fourth theme highlighted in this volume concerns the fact that children live in families. Childhood disability poses major costs for families as well as for the children themselves. If we take a broad definition of disability, then the way that children are able to function within their families should be considered a key indicator of the extent to which any particular health problem results in disability. Moreover, families are important advocates for children, often serving as the only effective coordinators of care.

Four articles in the issue address the role of the family in some detail. Mark Stabile and Sara Allin lay out a framework for measuring the economic costs to families and children; they consider medical costs, indirect costs to families in terms of lost work time (especially for mothers), and costs in terms of losses to the child's future productivity. (They do not take into account the costs paid by private insurance or the cost of decreased well-being of families.) Liam Delaney and James Smith consider U.S. data from the Panel Study of Income Dynamics that track children and families over time and allow researchers to measure the impact of childhood disability on adult outcomes and show that the consequences can be profound. Peter Szilagyi points out that the costs to families often depends on the type of health insurance available to them. Insured children with disabilities are more likely than uninsured children to have a usual source of care and to get necessary care. Such care may or may not lower costs, but is likely to improve the child's, and hence the family's, functioning.

James Perrin argues that assessments of quality of care need to consider disability, as well as the impact of interventions on children's functioning, in the context of their families. He stresses going beyond the purely "medical home" model of coordinated care that is often cited as an ideal in discussions of the quality of care to include the child's family home as well.

Another recurring theme is the importance of family advocacy for children with disabilities. Very often it is the family that coordinates care for the child and ensures that medical practitioners consider the child's functioning in various contexts. Thus, children with effective family advocates receive care that is likely to be of significantly higher quality than children whose families are less able to take on this role.

The Fragmentation of Disability Services
The fifth theme is the fragmentation of services for children with disabilities. One indication of the severity of the problem is that even as mental disabilities make up a growing share of children's disabilities, a disproportionate share of services for the disabled is still targeted at physical disabilities. Likewise, systems set up to deal with medical problems such as clinics for children with disabilities, or public insurance programs, are not coordinated with services at schools. And as the article by Laudan Aron and Pamela Loprest shows, even within the educational system itself many services are delivered in isolation from or even at cross purposes with each other. For example, children receiving services for disabilities funded by special education before entering formal schooling are not automatically connected to special education services once in school. Nor are services for high school students with disabilities linked with supportive services for adults with disabilities. High schools are required to deliver services designed to help students transition to adulthood, but no one has the responsibility to track children as they go out into the community and assess whether these services are effective.

One reason that health services for children with disabilities are delivered in a fragmented manner is that many children have only episodic health insurance coverage. Ironically, most children with disabilities who lack insurance are actually eligible for Medicaid or the Child Health Insurance Program (CHIP). Hence, as Szilagyi argues, the fact that the majority of uninsured children are actually eligible for either Medicaid or CHIP only emphasizes that universal coverage for all children would actually be an incremental step to more efficiently use the health care system, and not a major overhaul of the health care system. Szilagyi also supports searching for and enrolling more eligible children through enhanced outreach, as well as the concept of the medical home (to be used to integrate services, but broadened to include the family, as Perrin emphasizes). Broadening the concept of the medical home in this way would help to connect medical services to support services for families of children with disabilities and recognize the key role of families in the coordination of care.