Racial disparities in the use of chiropractic care under Medicare

Medicare covers chiropractic care, but the health-care community knows little about the demographic characteristics of older adults who use chiropractic services under the Medicare program. Researchers do not know the demographic composition of chiropractic users under Medicare, how the demographics of chiropractic use and rates of use have changed over time, and how users' characteristics vary geographically across the United States. An understanding of the demographics of chiropractic users can help chiropractic organizations, policy makers, and other stakeholders plan for an equitable allocation of resources to meet the chiropractic health-care needs of all of Medicare's beneficiaries.

The study intended to evaluate Medicare administrative data to determine (1) longitudinal trends in the demographic composition of the population that used chiropractic services, (2) longitudinal trends in rates of chiropractic use by demographic group, and (3) geographic variations in chiropractic use among minorities.

The research team used a serial cross-sectional design to analyze administrative data for beneficiaries of Medicare during the years 2002 to 2008, using a 20% random sample that provided those beneficiaries' racial and geographical characteristics. The team restricted the study's actual sample to adults aged 65 to 99 and defined chiropractic users as beneficiaries who had at least one paid claim for chiropractic care on a date of service in an analyzed calendar year.

For each state in the United States and the District of Columbia for each of the 7 years studied, the team determined the number of chiropractic users in total and the number of users in selected demographic categories and calculated percentage estimates and averages for each category. The team analyzed 2008 data for rates of use within racial groups and for geographic variations in those rates and quantified variations in rates by state using the coeffcient of variation (CV). The team mapped race-specific rates for selected minorities, categorized by quintiles, to illustrate geographic variations by state.

Analysis by beneficiary's race showed that the proportion of chiropractic users who were white hovered at 96% to 97% throughout the time period studied, while 1% to 2% were black. Each of the other racial categories comprised 1% or less of users, and the percentages showed little change over time. Rates among racial minorities showed greater geographic variation than did rates for whites. The greatest geographic variations in use by specific racial minorities occurred among Hispanics, Asians, and Native Americans.

The research team's results showed little longitudinal variation in the demographics of chiropractic use under Medicare but a striking difference in rates of use between whites and minorities, and substantial geographic variations in user rates among racial minorities. The research team's findings suggest the possibility that barriers may exist for minorities' access to chiropractic care. As minority populations in the United States continue to grow, the health-care community can expect that any impact on population health that these barriers cause will grow as well.