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Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  9. APPENDIX 1.

Objective:

Obesity is associated with adverse health outcomes in people with and without disabilities. However, little is known about disability prevalence among people who are obese. The purpose of this study is to determine the prevalence and type of disability among adults who are obese.

Design and Methods:

Pooled data from the 2003-2009 National Health Interview Survey (NHIS) were analyzed to obtain national prevalence estimates of disability, disability type and obesity. The disability prevalence was stratified by body mass index (BMI): healthy weight (BMI 18.5-<25.0), overweight (BMI 25.0-<30.0), and obese (BMI ≥ 30.0).

Results:

In this pooled sample, among the 25.4% of US adults who were obese, 41.7% reported a disability. In contrast, 26.7% of those with a healthy weight and 28.5% of those who were overweight reported a disability. The most common disabilities among respondents with obesity were movement difficulty (32.5%) and work limitation (16.6%).

Conclusions:

This research contributes to the literature on obesity by including disability as a demographic in assessing the burden of obesity. Because of the high prevalence of disability among those who are obese, public health programs should consider the needs of those with disabilities when designing obesity prevention and treatment programs.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  9. APPENDIX 1.

More than one third of US adults are identified as being obese, or having a body mass index (BMI, defined as weight in kilograms divided by height in meters squared) of 30 or greater (1). Moreover, disability affects more than 56 million people in the United States (2). While obesity might be a primary disabling condition, it is not identified among the leading disabling conditions (3). Obesity has been identified as a leading secondary condition experienced by people with a disability (4). Secondary conditions are potentially preventable health problems that occur after the acquisition of the primary disability condition (5). Among people with disabilities, obesity can lead to additional health problems, exacerbate existing health problems, and limit physical activity thereby increasing the severity of disability (6).

The prevalence of obesity can vary by type of disability (4). However, there is limited information on the prevalence of reported disability among people who are obese (7). Furthermore, there are no published reports on type of disability by BMI using data from the US (8). Using data from the 2003-2009 National Health Interview Survey (NHIS), we estimated the prevalence and type of disability among US adults, stratifying by BMI, including healthy weight (18.5 ≥ BMI < 25.0), overweight (25.0 ≤ BMI < 30.0) and obese (BMI ≥ 30.0).

Methods and Procedures

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  9. APPENDIX 1.

Data sources

The NHIS is a nationally representative in-person household survey of the civilian noninstitutionalized population of the United States. This study used demographic, health, behavioral risk, preventive health, and disability data on adults aged 18 years or older from three NHIS files: household, family, and sample adult surveys. NHIS is in accordance with Department of Health and Human Services regulations (45 CFR 46) for protection of human subjects; a detailed description of the compilation and use of NHIS is available at http://www.cdc.gov/nchs/nhis.htm.

Obesity definition

BMI was calculated based on self-reported height and weight. Adults were considered of healthy weight if 18.5 ≤ BMI < 25, overweight if 25 ≤ BMI < 30, and obese if BM ≥ 30.

Disability definition

The Americans with Disabilities Act (ADA) defines disability as a physical or mental impairment that substantially limits one or more major life activities (9). Consistent with the ADA, we used the NHIS questions to construct two disability subcategories, basic actions difficulty and complex activity limitation (10). Basic actions difficulties include movement difficulty (e.g., difficulty walking), emotional difficulty (e.g., mental illness), sensory difficulty (e.g., being deaf) and cognitive difficulty (e.g., dementia). Complex activity limitations, or difficulties encountered by people in performing tasks or social actions, include activities of daily living (ADL) (e.g., getting dressed) or instrumental activities of daily living (IADL) limitation (e.g., meal preparation), social limitation (e.g., going outside) and work limitation (5, 10). Respondents who were identified as having a basic or complex activity limitation were denoted as having any limitation. These categories and their various components were used to assess the association between weight status and disability.

Statistical analyses

To obtain national estimates of disability, type of disability, and obesity prevalence data from multiple years were combined to ensure stable estimates. Because adjusted measures of obesity have not shown significant change from 2003 to 2010 (1), the survey years of 2003-2009 were combined. A total of 190,786 respondents completed the sample adult questionnaire from 2003 to 2009, with an aggregate sample adult response rate of 69.0%. Respondents were excluded from the analysis if they had missing data on BMI (n = 8,645), had an extreme BMI value (>85) (n = 3), were underweight (n = 3,342), or were pregnant (n = 2,092). Exclusions were not mutually exclusive. A total of 176,847 respondents were included in the analysis. For weight status, the sample sizes were: 18.5-<25 (n = 66,698), 25-<30 (n = 63,510), ≥30 (n = 46,639). The data were weighted to account for differential probability of selection and, in part, to adjust for nonresponse. Estimates were age-adjusted to the 2000 US standard population.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  9. APPENDIX 1.

Overall, 31.3% of the total population was identified as having a disability compared to 26.7% of healthy weight adults, 28.5% of overweight adults, and 41.7% of obese adults. Among healthy weight adults, 24.7% reported having a basic actions difficulty, while 26.6% of overweight and 39.7% of obese adults reported a basic actions difficulty. Movement difficulty was the most common type of basic actions difficulty, affecting 16.8% of healthy weight, 19.1% of overweight, and 32.5% of obese adults. This was followed by sensory difficulties, which affects both 11.8% of healthy weight and overweight adults, and 15.4% of obese adults. Hearing difficulties were fairly similar among the three weight classifications, ranging from 3.8 to 5.0%. Among adults with a healthy weight, 8.9% had a visual difficulty, compared to 8.4% of overweight, and 11.5% of obese adults. Emotional difficulty was the least common type of basic actions difficulty for healthy weight adults, affecting 2.4%, yet cognitive difficulties were the least common disability among obese adults, affecting 3.6%. The least common basic actions difficulties among overweight adults were both emotional and cognitive difficulties, each affecting 2.4% (Table 1).

Table 1. Disability prevalence estimates of adultsa,b overall and by weight status, 2003–2009 National Health Interview Survey
 TotalHealthy weightcOverweightdObesee
%± 95% CI%± 95% CI%± 95% CI%± 95% CI
  • a

    Adults aged 18 years and over, age adjusted to the 2000 US standard population.

  • b

    Excluding those respondents with extreme BMI values or underweight (<18.5 or >85) and pregnant women.

  • c

    Includes those respondents whose BMI is categorized as 18.5 to <25.

  • d

    Includes those respondents whose BMI is categorized as 25 to <30.

  • e

    Includes those respondents whose BMI is categorized as 30 or greater.

  • f

    Disability groups are not mutually exclusive and respondents may be represented in more than one type of disability.

  • g

    Statistically significantly different from healthy weight adults at P < 0.001.

  • h

    Statistically significantly different from healthy weight at P = 0.009.

  • CI: confidence interval; ADL: activities of daily living; IADL: instrumental activities of daily living.

Disabilityf
Basic actions difficulty29.40.324.70.426.6g0.439.7g0.5
 Movement difficulty21.80.216.80.319.1g0.332.5g0.5
 Sensory difficulty12.70.211.80.311.80.315.4g0.4
  Visual difficulty9.40.28.90.38.4h0.311.5g0.4
  Hearing difficulty4.30.13.80.24.3g0.25.0g0.3
 Emotional difficulty3.00.12.40.12.40.24.6g0.2
 Cognitive difficulty2.90.12.90.22.4g0.13.6g0.2
Complex activity limitation14.40.212.30.312.10.320.5g0.4
 Self-care4.10.13.90.23.1g0.25.8g0.2
  ADL limitation1.80.11.80.11.3g0.12.5g0.2
  IADL limitation3.80.13.60.22.9g0.25.3g0.2
 Social limitation7.30.26.00.25.80.211.2g0.3
 Work limitation11.50.29.80.39.60.316.6g0.4
Any Limitation31.30.326.70.428.5g0.441.7g0.6
No Limitation68.70.373.30.471.5g0.458.3g0.6

Some 12.3% of healthy weight, 12.1% of overweight, and 20.5% of obese adults reported having a complex activity limitation. Work limitation was the most common ranging from 9.6 to 16.6%, followed by social limitation at 6.0% of healthy weight, 5.8% of overweight, and 11.2% of obese adults. ADL limitation was the least common type of complex activity limitation for all three weight statuses, ranging from 1.3 to 2.5%. All estimates for disability were significantly higher for people who were obese compared to those with a healthy weight (P < 0.001) (Table 1).

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  9. APPENDIX 1.

This brief report is among the first to describe the prevalence and type of disability among adults who are obese. The findings reveal that of the estimated 53.4 million obese adults, over 41% have at least one type of disability.

The prevalence of movement difficulty almost doubled from those with a healthy weight to those with a BMI 30 or greater (16.8-32.5%). Movement difficulty may hinder physical activity, preventing people with disabilities from meeting the physical activity guidelines for adults with disabilities (11). The prevalence of visual limitation was higher for obese adults compared to those with a healthy weight or overweight. This, in part, might be attributed to diabetes. That is, the risk of diabetes, which can lead to visual limitation through diabetic retinopathy, increases with BMI (12). Visual difficulty might also limit participation in physical activity which could increase the risk of obesity. The prevalence of cognitive difficulty and self-care limitation was higher for obese adults compared to those with a healthy weight or overweight. However, the prevalence of cognitive difficulty and self-care limitation was higher among those of a healthy weight compared to those that are overweight. This might be attributed to diet restrictions or reliance on a caregiver for meal preparation. However, explaining these differences is beyond the scope of this analysis and is a direction for future work.

There are several limitations to our analysis. First, our findings likely underestimate disability among people who are obese. BMI may not be the best measure of obesity for people with certain disabling conditions due to body composition differences, for example spinal cord injury (13). Alternate measures of obesity, for example waist circumference (14), may be appropriate for some people with disabilities. In addition, the use of the obesity threshold (BMI ≥ 30) may underestimate obesity in some people with disabilities, including those with spinal cord injury (13). Second, BMI measures in the NHIS are based on self-reported height and weight and might underestimate obesity prevalence due to reporting bias (15). However, we completed a complementary analysis using data from the 2005-2010 National Health and Nutrition Examination Survey (which calculates BMI using measured height and weight), and our estimates were understated (Appendix 1). Third, the results might be sensitive to the definition of disability used. The disability definition used here and developed by Altman and Bernstein (10) is detailed, inclusive, and consistent with the definition used by ADA (9) and, thus, we would argue, appropriate for public health purposes. However, if others were to use a more limited measure of disability the findings might differ (e.g., disability linked solely to the ability to work) (2). Fourth, since NHIS is a cross sectional survey, we cannot determine causality. Disability may lead to obesity, while obesity may also lead to disability. To reduce this issue, we completed a sensitivity analysis excluding those respondents whose limitation was weight related and found similar results. These results are available from the authors. Finally, the NHIS does not survey institutionalized individuals or military personnel on active duty, therefore, our results cannot be generalized to these populations.

In conclusion, this research contributes to the literature on obesity prevalence by including disability as a demographic characteristic and considering type of disability in assessing the burden of obesity in a nationally representative US sample. People with disabilities comprise 26.7% of the healthy weight adult population, but 41.7% of obese adults. Knowing that a large percentage of people with obesity have a disability, as well as the type of disability, will aid public health officials in designing interventions to reduce obesity that are inclusive of—and accessible to—people with disabilities.APPENDIX

Acknowledgements

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  9. APPENDIX 1.

BA, ECL, VC, and HW conceived the study design. ECL conducted statistical analyses. All authors were involved in writing and reviewing the paper and had final approval of the submitted version.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  9. APPENDIX 1.
  • 1
    Flegal KM, Carroll MD, Kit BK, et al. Prevalence of obesity and trends in the distribution of body mass index among US adults, 1999-2010. JAMA 2012; 307: 491-497.
  • 2
    Brault M. Americans with disabilities: 2010. Current population reports, P70-131, US Census Bureau, Washington, DC, 2012.
  • 3
    Centers for Disease Control and Prevention. Prevalence and most common causes of disability among adults—United States, 2005. MMWR 2009; 58: 421-426.
  • 4
    Weil E, Wachterman M, McCarthy EP, et al. Obesity among adults with disabling conditions. JAMA 2002; 288: 1265-1268.
  • 5
    Institute of Medicine. Disability in America: toward a national agenda for prevention. Washington, DC: National Academy Press; 1991.
  • 6
    Institute of Medicine. The future of disability in America. Washington, DC: National Academy Press; 2007.
  • 7
    Okoro CA, Hootman JM, Strine TW, et al. Disability, arthritis and body weight among adults 45 years and older. Obes Res 2004; 12: 854-861.
  • 8
    Lidstone JSM, Ells LJ, Finn P, et al. Independent associations between weight status and disability in adults: Results from the health survey for England. Public Health 2006; 120: 412-417.
  • 9
    American with Disabilities Act of 1990. P.L 101-2336., 104 Stat. 328 ( 1991).
  • 10
    Altman B, Bernstein A. Disability and health in the United States, 2001-2005. Hyattsville, MD: National Center for Health Statistics; 2008.
  • 11
    US Department of Health and Human Services. 2008 Physical activity guidelines for Americans. 2009. Available at: http://www.health.gov/paguidelines/.
  • 12
    Ford ES, Williamson DF, Liu S. Weight change and diabetes incidence: findings from a national cohort of US adults. Am J Epidemiol 1997; 146: 214-222.
  • 13
    Gorgey AS, Gater DR. Prevalence of obesity after spinal cord injury. Top Spinal Cord Inj Rehabil 2007; 12: 1-7.
  • 14
    Flegal KM, Shepherd JA, Looker AC, et al. Comparisons of percentage body fat, body mass index, waist circumference, and waist-stature ratio in adults. Am J Clin Nutr 2009; 89: 500-508.
  • 15
    Stommel M, Schoenborn CA. Accuracy and usefulness of BMI measures based on self-reported weight and height: findings from the NHANES & NHIS 2001-2006. BMC Public Health 2009; 9: 421.

APPENDIX 1.

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  9. APPENDIX 1.
Table APPENDIX. Disability prevalence estimates of adultsa,b overall and by weight status, 2005–2010 National Health and Nutrition Examination Survey
 TotalHealthy weightcOverweightdObesee
%± 95% CI%± 95% CI%± 95% CI%± 95% CI
  • a

    Adults aged 20 years and over, age adjusted to the 2000 US standard population.

  • b

    Excluding those respondents with extreme BMI values or underweight (<18.5 or >85) and pregnant women.

  • c

    Includes those respondents whose BMI is categorized as 18.5 to <25.

  • d

    Includes those respondents whose BMI is categorized as 25 to <30.

  • e

    Includes those respondents whose BMI is categorized as 30 or greater.

  • f

    Disability groups are not mutually exclusive and respondents may be represented in more than one type of disability.

  • CI: Confidence Interval; ADL: Activities of Daily Living; IADL: Instrumental Activities of Daily Living.

Disabilityf
Basic actions difficulty41.21.337.41.739.02.046.41.7
 Movement difficulty24.41.120.01.121.61.430.51.6
 Sensory difficulty22.51.021.11.322.31.623.81.4
  Visual difficulty17.10.915.61.316.91.418.51.3
  Hearing difficulty7.80.57.70.87.80.98.00.8
 Emotional difficulty7.00.76.11.05.91.08.81.1
 Cognitive difficulty6.00.56.60.95.30.86.30.8
Complex activity limitation20.91.018.11.318.21.325.61.6
 Self-care11.10.69.00.99.40.814.11.2
  ADL limitation5.10.44.10.64.00.67.00.8
  IADL limitation9.40.57.40.88.00.712.11.0
 Social limitation8.70.56.80.86.80.712.21.1
 Work limitation17.61.015.31.315.11.321.71.6
Any limitation42.81.339.21.740.92.047.71.7
No limitation57.21.360.81.759.12.052.41.7