Decomposition of changes in diabetes inequalities during 2001−2011 and 2011−2018.

Decomposition of changes in diabetes inequalities during 2001−2011 and 2011−2018.</p

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AimsThe overall prevalence of diabetes has increased over the past two decades in the United States, disproportionately affecting low-income populations. We aimed to examine the trends in income-related inequalities in diabetes prevalence and to identify the contributions of determining factors.MethodsWe estimated income-related inequalities in diagnosed diabetes during 2001−2018 among US adults aged 18 years or older using data from the National Health Interview Survey (NHIS). The concentration index was used to measure income-related inequalities in diabetes and was decomposed into contributing factors. We then examined temporal changes in diabetes inequality and contributors to those changes over time.ResultsResults showed that income-related inequalities in diabetes, unfavorable to low-income groups, persisted throughout the study period. The income-related inequalities in diabetes decreased during 2001−2011 and then increased during 2011−2018. Decomposition analysis revealed that income, obesity, physical activity levels, and race/ethnicity were important contributors to inequalities in diabetes at almost all time points. Moreover, changes regarding age and income were identified as the main factors explaining changes in diabetes inequalities over time.ConclusionsDiabetes was more prevalent in low-income populations. Our study contributes to understanding income-related diabetes inequalities and could help facilitate program development to prevent type 2 diabetes and address modifiable factors to reduce diabetes inequalities.</div

Decompositions of income-related inequalities in diabetes in 2001, 2011, and 2018.

Decompositions of income-related inequalities in diabetes in 2001, 2011, and 2018.</p

Income-related inequalities in diabetes by sex, age, and race/ethnicity among US adults aged ≥ 18 years, 2001–2018.

The concentration index (CI) measures the inequality in diabetes prevalence over the distribution of income. Negative CIs indicate that diabetes was concentrated among lower-income groups, and a larger CI (in absolute value) indicates a greater degree of inequality.</p

Relative contributions of determining factors to income-related inequalities in diagnosed diabetes, 2001−2018.

For each year, the length of the sub-bar indicated the numeric value of each factor’s relative contribution to the overall CI, and the sum of numeric values from all factors was equal to the overall CI.</p