Survey of Income and Program Participation (SIPP): Topical Questions on Disability

My search for disability statistics led me to the 314-page 2008 Panel Core Questionnaire for the U.S. Census Bureau's Survey of Income and Program Participation (SIPP).  While the Core Questionnaire did have some disability-related questions, those questions tended not to ask about the nature or extent of a disability; the concern was, rather, with whether the disability interfered with (or was perhaps the source of) the respondent's income and benefits.  It seemed that disability-oriented topical questions posed to the SIPP's 2008 Panel of respondents would shed more light on the nature and extent of disabilities experienced by people in the United States.

As with the Core Questionnaires, the Census Bureau's SIPP website did not provide ready links to its Topical Module Questionnaires after 2004.  Fortunately, the 2008 Panel SIPP Data Product Schedule found on one of the pages in that website indicated that data collection for the Work Disability History module was scheduled to take place as part of Wave 2, in January through April 2009, and that the corresponding data products were expected to be released in April 2010.  Data collection for the other disability-related Topical Modules, Functional Limitations and Disability for adults and children, was scheduled to take place as part of Wave 6, in summer 2010, with data products being released in September 2011.

By pleasant coincidence, the 2008 Panel Wave 6 Topical Modules seemed to be included on the same RegInfo.gov page from which I had previously obtained the 2008 Panel Core Questionnaire, so it was easy to get the Wave 6 modules.  The link provided on that page produced an 82-page Wave 6 Topical Modules Items Booklet, in which the Functional Limitations and Disability section ran from pages 31 to 53.  A preliminary look at some of these questions confirmed that they were not at all limited to income production, as had been the case with disability-related questions in the Core Questionnaire.

The remaining step was to find the Wave 2 Topical Modules Booklet that would hopefully include the Work Disability History module.  A search led to a Federal Register entry that cited the same OMB Control Number 0607-0944 that had applied to the 2008 Panel Core Questionnaire.  A search for that number led to a different RegInfo.gov page, where I downloaded a 2008 Panel Wave 2 Topical Modules Items Booklet, in which the Work Disability Topical Module appeared on pages 1 through 5 (PDF pages 3 through 7).  As the "work disability" moniker suggests, the questions in this module appeared to be oriented toward disabilities that interfered with work.

My ultimate purpose, in this pursuit, was to become informed on defensible ways of estimating the numbers of persons with disabilities in a particular location.  The page counts (above) told me that I was likely to get a more extensive treatment of disability concepts in the Wave 6 Topical Module, and it also seemed that that module's questions would take a broader perspective on the meaning of disability.  In a subsequent post, I look more closely into that module.

Definitions of Disability

The Web is filled with references to handicapped people and disabled people and people with disabilities.  But what is a disability?

Iezzoni and Freedman (2008) describe a "medical model of disability" (p. 332) originating in the 19th century. That model, they say, treats disability as a form of illness; and illnesses, in the medical model, are typically diagnosed in individuals and treated by doctors.  Against this, Iezzoni and Freedman contrast the "social model" (p. 333), which considers disability a social phenomenon.  In the words of the Fundamental Principles of Disability (1975) produced by the now apparently defunct Union of the Physical Impaired Against Segregation, "Disability is something imposed on top of our impairments, by the way we are unnecessarily isolated and excluded from full participation in society" (p. 3, cited by Oliver (1996, p. 22)).  In other words, there are a great many physical and mental impairments - the need to wear eyeglasses is an example - but not all impairments are treated equally; some result in much more isolation or stigma than others.

Within the social model of disability, Iezzoni and Freedman (2008) favor the definitional approach adopted by the World Health Organization's (WHO, 2009) International Classification of Functioning, Disability and Health (ICF):

The ICF puts the notions of ‘health’ and ‘disability’ in a new light. It acknowledges that every human being can experience a decrement in health and thereby experience some degree of disability. Disability is not something that only happens to a minority of humanity. The ICF thus ‘mainstreams’ the experience of disability and recognises it as a universal human experience. By shifting the focus from cause to impact it places all health conditions on an equal footing allowing them to be compared using a common metric – the ruler of health and disability. Furthermore ICF takes into account the social aspects of disability and does not see disability only as a 'medical' or 'biological' dysfunction. By including Contextual Factors, in which environmental factors are listed ICF allows to records the impact of the environment on the person's functioning.  [I have notified the webmaster of incoherence in that last sentence.]

Iezzoni and Freedman (2008) note, however, that different definitions serve different purposes, and that at present there are numerous legal definitions in use in the United States.  Two of the most prominent definitions they cite are those of the Americans with Disabilities Act of 1990 (ADA) and the Social Security Administration (SSA).  Section 12102(1) of the ADA defines disability as meaning, with respect to an individual, "(A) a physical or mental impairment that substantially limits one or more major life activities of such individual; (B) a record of such an impairment; or (C) being regarded as having such an impairment."  By contrast, the Social Security Advisory Board (2003) says that the Social Security Act of 1956 defined disability as “inability to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or to be of long-continued and indefinite duration” (p. 3); but this definition, they say, is increasingly subject to challenge.

The Census Bureau is yet another important source of disability definitions.  Definitions used by the Census Bureau in recent years include the definition of "work disability" in the Current Population Survey; the definition of disability in the Survey of Income and Program Participation; and the definition of disability in the American Community Survey (ACS).  Among these and other data sources that have been used by the Census Bureau, the ACS is especially useful for obtaining local data at the city and county levels.  The 2008 ACS Subject Definitions operationalize the concept of disability in a set of related questions posed to survey participants:

Using models of disability from the Institute of Medicine and the International Classification of Functioning, disability is defined as the restriction in participation that results from a lack of fit between the individual’s functional limitations and the characteristics of the physical and social environment. So while the disability is not seen as intrinsic to the individual, the way to capture it in a survey is to measure components that make up the process. The American Community Survey identifies serious difficulty in four basic areas of functioning: vision, hearing, ambulation, and cognition. Described below, the ACS asks respondents about serious difficulty and the resulting data can be used individually or combined. The ACS also includes two questions to identify people with difficulties that might impact their ability to live independently. In the 2008 American Community Survey, there are three disability questions, two with subparts totaling six questions in all . . . . (p. 38).

These various definitions, including especially that of the ACS, will be relevant to further exploration of data on disabilities within the U.S.