Emerging Etiology of Disablement: State and National Policy Implications

Presenter Name: Kiyoshi Yamaki, Ph.D., Violet Rutkowski-Kmitta, MPH; & Glenn T. Fujiura, Ph.D.

Institution: Center on Emergent Disability, Institute on Disability and Human Development, University of Illinois at Chicago

Primary Research Interests: Demography of the disability service system, developmental disabilities, vocational rehabilitation, health and health promotion, statistical surveillance of disability

INTRODUCTION

Seelman and Sweeney (1995) proposed a "new universe" of disability hypothesis, suggesting significant change in the population of Americans with a disability as a consequence of changing etiologies and patterns of risks. In their analysis, fundamental transformations in the nation’s social landscape -- in the distribution of wealth, the character of poverty, and cultural shifts – may alter the form and magnitude of disability risk. The new universe hypothesis suggests certain dynamics should be observed in the manifestation of disability: (1) we should observe increases in magnitude and rates of disability among those most vulnerable; and (2) what has been broadly termed, "socio-environmental" risk factors -- should become more prominent as predictors of disability status. The presentation summarizes findings from two components of the larger series of studies conducted by the Center on Emergent Disability at the University of Illinois at Chicago that evaluated emerging causes, consequences, and population shifts that may challenge the capacity of health and rehabilitation systems. The two studies involved a systematic canvas and evaluation of disablement-related surveillance available through state public health surveillance systems and secondly, a series of secondary analyses of national data sets. While we know a great deal about the etiology of specific impairments and the linkage of various risk factors to disability, we know very little about underlying causes and their distribution from a population perspective. The major national data systems really focus on etiology. Our intent was to employ the substantial base of health surveillance that is ongoing at the state level in order to evaluate its potential utility in a large scale analysis of etiology. While state-level data is often notoriously difficult to access, unreliable, these state-level systems emphasize collection of data on factors strongly predictive of disability status – injury & trauma, maternal and child health statistics, etc. In addition, states frequently conduct pilot projects whose methods may be of interest to the disability community but are largely invisible beyond specialized constituencies. The central question was the viability of assessing changing trends in risk for disablement through state-level surveillance (i.e., disability etiology). The second set of studies focused on secondary analyses on the correlates of change in the population of Americans with a disability.

METHODS

In the public health surveillance component, we canvassed all states to identify state-level surveillance systems with "disablement" outcomes. Six forms of state system surveillance provided some form of disablement outcomes: asthma, near drowning, firearm injury, motor vehicle crash reports, workman’s compensation, and lead poisoning. The secondary analysis project involved evaluations of National Health Interview Survey (NHIS) for the years 1983 through 1997, and Survey of Occupational Illness and Injuries.

RESULTS

  1. Specific findings of the secondary analyses include:
  • General Trends in the Population: Between 1983 and 1996, the overall population of Americans with a disability increased 5.3 million, or 16% -- from 32.8 million to 38.1 million. The proportion living below the poverty threshold increased 68% during this period, in contrast to the 10% increase among those above the poverty level. Disability prevalence increased faster among children and young adult cohorts than in the middle and older cohorts. While the overwhelming majority of Americans with a disability continued to live with other family members, the number living alone increased most rapidly, with a 35% growth from 1983 to 1996.
  • Injury: Chronic conditions caused by injury were the main sources of disability for 3% of the American population during the 14-year period of 1983 to 1996. The majority were conditions of the musculoskeletal system and connective tissue. A significant share of these were a consequence of motor vehicle and/or work related injuries that occurred more than five years ago. Injury was related to one fifth of all disability-related conditions in America. From 1983 to 1996, injury’s contribution to disability did not appear to have changed, though it varied across different subgroups of the population. Injury-related disability was more prominent among males and young adults aged between 19 and 44.
  • Occupational Injury: The Survey of Occupational Illness and Injuries (SOII) provides the most comprehensive national and state portrait of occupational injuries and illnesses; other surveillance systems are condition-specific (e.g., lead exposure, asthma, and skin diseases) or industry-specific (e.g, mining), and limited in the number of participating states. Though millions of injuries and illnesses related to work are reported each year, the majority appeared to be minor. The link between work-related injuries and long-term disablement is not determinable from these surveillance systems. Similarly, the workman’s compensation program defines “disability” as the worker’s earning capacity, and does not represent impairments or functional limitations in daily activity. Therefore, it is hard to estimate the work-related incidence of long-term disability from compensation data. Nationally, it is estimated that more than 600,000 workers claim disability and fatality benefits each year. 
  • Chronic Diseases: Chronic conditions were the main cause of activity limitations among Americans with disabilities (approximately 70%). This proportion remained constant during the period between 1983 and 1995. Age, gender, race and income status affected exposure to chronic conditions. Analysis of longitudinal trends yielded mixed results across conditions -- asthma was the most prevalent disability-causing condition for children under age 18 and the proportion of children who were limited by asthma increased during the 1990s. For Americans aged 18 to 44, disc disorder was the single most prominent chronic condition causing disability and its prevalence was increasing. Accounting for over 40% of all chronic conditions causing disability, heart disease and osteoarthritis were the most frequent disability-causing conditions for people aged between 45 and 69. These conditions were also prominent among individuals over the age of 70.
  1. Trauma/Injury systems provide some potentially good examples for linkage of disablement outcomes to surveillance systems, but the vast majority of systems define outcomes in terms of mortality or acute conditions. Disability, when it is considered in some form or format as an outcome, is more an afterthought than a consequence of direct interest.
  2. Specific findings of the state systems include: 
  • Asthma: Most of the state-level asthma information on adults has been collected through the Behavioral Risk Factor Surveillance System (BRFSS). In 1999, the BRFSS data from participating states indicated that the prevalence of lifetime asthma among adults ranged from 9% for Missouri and South Carolina to 12% for California and Oregon. The data indicated that young adults and females were more likely to have asthma. Breakdowns across race/ethnicity however, yielded no clear themes. Despite the increased rates of asthma found among children in national analyses, state-level data on children is not widely collected.
  • Near Drowning: There are three federal data systems that do collect information on near drowning as a mechanism of injury, these are: the National Electronic Injury Surveillance System (NEISS), the National Health Interview Survey (NHIS), and the National Incidence Study of Child Abuse and Neglect (NIS). At the state level, only three states (Arizona, Texas, and Oklahoma) currently maintain drowning/near drowning database systems and only one state (California) has used existing hospital discharge data and surveillance studies to examine near drowning in its reporting program. In most cases, the outcome of a near drowning is examined only in terms of mortality or hospitalization. Based on limited state systems, we estimated near drowning incidents at 1 to 3.1 per 100,000 population, and neurological impairment outcomes at 0.1 to 0.32 per 100,000.
  • Firearm Injury: National data from National Health Interview Survey, Ntl Hospital Discharge Survey, National Hospital Ambulatory Medical Care Survey, Ntl Electronic Injury Surveillance System, and Ntl Crime Victimization Survey. State-level surveillance from CDC Firearm Injury Surveillance Study in CA, CO, MD, MA, MO, NYC, OK, WA, WI, and the Harvard Injury Control Research Center with pilot systems in CT, ME, MD, MI, UT, WI, and local areas in PA, GA, & CA. Limited disablement data based on linkages to trauma registry or hospital discharge. Population-based studies show a significant rate of disability, somewhere between 3 to 40% of nonfatal gunshot injuries resulting in permanent, primarily neurologic, damage such as a traumatic brain injury and a spinal cord injury. Few state-level morbidity or disability surveillance systems exist that can determine the disabling outcomes of firearm injuries. Mortality data has been more readily accessible and collected.
  • Motor Vehicle Crash: Nonfatal injuries resulting from motor vehicle crashes (MVCs) are estimated to be at 3.2 million per year, a rate of 1,161 injuries per 100,000 Americans. Although MVCs have been cited as a cause of severe disabling outcomes (e.g., traumatic brain and spinal cord injuries), no dependable prevalence estimates have been made regarding the number of injured persons who sustain a long-term disability. There are a number of national and state level surveillance systems tracking injuries associated with MVCs based on the on-sight examination of non-medical professionals (i.e., police officers) and the administrative records from hospitals. However, none of these surveillance systems provide any data beyond hospital discharge. Data collection on MVC fatalities from these surveillance systems has been relatively manageable. Counting the multitude of possible injuries and long-term disability remains a continuous challenge. Rates of MVC related disability derived from these systems ranged from 8 to 26 per 100,000 in the population.

CONCLUSIONS

First, that the population of Americans with disability, however defined, is dynamic rather than static. The dynamism is closely linked to larger forces of population change in the nation such as aging, exposure to risk, and increased poverty. Second, that longitudinal analyses suggests changes in the nature of risk for disability in the nation, particularly among the poor and children. Third, that the issue of poverty should be a fundamental priority for disability policy. Fourth, that our basis for understanding etiological change in disability is woefully inadequate and that new mechanisms and strategies would be necessary. Fifth, that disablement remains largely invisible to public health and public health surveillance.

IMPLICATIONS

Research:

  1. The field of disability has yet to address systematically the context of risk in America – the epidemiology, magnitude and patterns of vulnerability to disability.

Policy:   

  1. The visibility of disability needs to be elevated among state public health systems.

Training/Intervention:

  1. The visibility of disability needs to be elevated among state public health policy makers and workers.