Disparity Indices and Overweight: Frame of Reference

Area of Science:

• Public Health
• Health Disparities Research
• Epidemiology

Background:

• Body Mass Index (BMI) is a key indicator of overweight and obesity.
• Income disparities are recognized social determinants of health impacting BMI.
• Standardizing disparity measures across states is challenging.

Purpose of the Study:

• To compare state-level BMI rankings using national versus state-specific income disparity indices.
• To evaluate the concordance between national and state-specific disparity measures.
• To determine the influence of index choice on public health interpretations.

Main Methods:

• Utilized 2016 Behavioral Risk Factor Surveillance System data.
• Employed Spearman Rank Order Correlation with Bonferroni adjustment to assess relationships.
• Applied kappa statistic to measure concordance between indices.

Main Results:

• A very weak monotonic relationship (ρ=0.11, p=0.46) was found between the two disparity indices.
• The kappa statistic (κ=0.02, p=0.43) indicated poor concordance between national and state-specific indices.
• State rankings of BMI varied considerably depending on the disparity index used.

Conclusions:

• The choice of income disparity index significantly impacts the interpretation of state-level BMI data.
• Using a national standard may obscure state-specific health realities compared to state-specific data.
• Findings underscore the need for careful selection of disparity metrics in public health research and policy.