Online Program

Prevalence of obesity among youth with intellectual disabilities: Comparison of cut-points

Sunday, November 3, 2013

E. Andrew Pitchford, MS, CAPE, School of Kinesiology, University of Michigan, Ann Arbor, MI
Dale A. Ulrich, PhD, School of Kinesiology, University of Michigan, Ann Arbor, MI
OBJECTIVE: The purpose of this study was to compare the prevalence of obesity across two international growth references [World Health Organization (WHO); International Obesity Task Force (IOTF)] among a large sample of youth with intellectual disabilities (ID). Discrepancies between published obesity prevalence rates among youth with ID are likely due to the use of different growth references. However, no studies have directly compared the performance of multiple growth references for youth with ID. METHODS: The records of 3,736 youth (59% male; 8-18 years) were available from the Special Olympics International Healthy Athletes Health Promotion database (2007-2011) after data cleaning. BMI (kg/m2) was calculated from anthropometric measurements and prevalence of obesity was determined using WHO and IOTF criteria. Differences between growth references were examined through descriptive statistics (proportions, 95% CI), proportions tests and kappa statistics. Analyses were conducted for the entire sample, by gender, and by age with bootstrapping procedures. RESULTS: Estimates of obesity prevalence from WHO (30.91% ± 1.49%) criteria were significantly higher than IOTF (25.96% ± 1.41%; p<.001) cut-points. Differences are substantially larger when stratified by age and gender. The largest difference observed was 15%. Despite large differences between prevalence estimates, agreement of obesity classification was high. Kappa statistics ranged from .69 to .99, with most above .80 indicating good agreement. CONCLUSIONS: Prevalence estimates of obesity for youth with ID varied significantly between growth references. Differences are largest when prevalence rates are calculated by specific age groups and genders and should be considered when interpreting results across studies.

Learning Areas:

Public health or related research

Learning Objectives:
Compare differences in the prevalence of obesity based on the WHO growth reference and IOTF cut-points from a sample of youth with intellectual disabilities participating in Special Olympics within the United States between 2007 and 2011.

Keyword(s): Disability, Obesity

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: Our research center is currently engaged in numerous projects examining the role of physical activity on obesity in populations with developmental disabilities. Special Olympics International, the organization from which these data originate, determined that I was qualified to conduct the analyses used in this study.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.