Area-Level Sociodemographic Differences Between Indian Health Service Purchased/Referred and Non-Purchased/Referred...

Area of Science:

• Public Health
• Health Disparities
• Epidemiology

Background:

• Purchased/Referred Care Delivery Area (PRCDA) counties are designated for American Indian and Alaska Native (AIAN) healthcare eligibility.
• Cancer statistics for AIAN populations are often limited to PRCDA counties due to concerns about racial misclassification.
• Potential sociodemographic differences between PRCDA and non-PRCDA counties are not well-described, leading to unknown selection bias.

Purpose of the Study:

• To describe ecological differences in county-level characteristics between PRCDA and non-PRCDA counties.
• To assess potential selection bias introduced by restricting AIAN cancer statistics to PRCDA counties.

Main Methods:

• Utilized the University of California, San Francisco Health Atlas data for 3152 counties.
• Compared county-level demographic, socioeconomic, healthcare access, and health outcome data between PRCDA and non-PRCDA counties.
• Employed Pooled or Welch t-tests to evaluate statistical differences in mean demographic levels.

Main Results:

• Observed statistically significant differences in demographics, socioeconomic factors, healthcare access, and health outcomes between PRCDA and non-PRCDA counties.
• Included variations in age, poverty, unemployment, educational attainment, insurance status, health behaviors (e.g., smoking, physical inactivity), and chronic conditions (e.g., diabetes, hypertension).

Conclusions:

• County-level characteristics exhibit variability between PRCDA and non-PRCDA areas.
• Excluding AIAN individuals in non-PRCDA counties from cancer statistics may introduce bias in risk estimates.
• These findings underscore the importance of considering broader geographic and sociodemographic contexts in health research for AIAN populations.