Learning from Kindergarteners — Uncovering Racial and Socioeconomic Disparities in Alaska's Vaccination Rates

Wednesday, 20 August 2014
Exhibit hall (Dena'ina Center)
Brian Yablon, MD , CDC/State of Alaska, Anchorage, AK
Joseph B McLaughlin, MD , Alaska Division of Public Health, Anchorage, AK
INTRODUCTION:  CDC’s National Immunization Survey data for 2008–2012 revealed that <60% of Alaskan children received 4 doses of diphtheria, tetanus, acellular pertussis (DTaP) vaccine by age 19 months. We partnered with school districts to understand how region, socioeconomic status (SES), and race influence Alaska’s toddler vaccination coverage.

METHODS:  Alaska’s 4 largest districts provided medically-verified vaccination records for kindergarteners enrolled in 2013–2014. We graphed up-to-date DTaP vaccination coverage by age per the Advisory Committee on Immunization Practices schedule.  We stratified analyses by race and free/reduced lunch eligibility (SES proxy). We calculated district-adjusted coverage rate differences (aCRD) within racial strata by SES and within SES strata by race.

RESULTS:  The 7,304 records reviewed represented 69% of Alaska’s kindergarteners. DTaP vaccination coverage was 82% at 3 months (1 dose), 69% at 5 months (2 doses), 59% at 7 months (3 doses), and 54% at 19 months (4 doses). At 24 months, coverage improved to 69%, with differences by strata. Among American Indian/Alaska Native (AI/AN) children, SES did not significantly affect coverage. Among non-AI/ANs, high-SES children had higher coverage than low-SES children (aCRD: 11.9%; 95% confidence interval [CI]:  9.5%–14.3%). Among low-SES children, district modified the effect of race (p<0.01); AI/AN children had significantly higher coverage in 2/4 districts (aCRD: 16.4%; 95% CI: 11.3%–21.5%), with no significant difference elsewhere (aCRD: 2.5%; 95% CI: -5.6%–10.6%). Among high-SES children, race did not significantly affect coverage.

CONCLUSIONS:  Socioeconomic and racial coverage disparities, along with drop-off in timely receipt of consecutive DTaP doses, underscore systemic gaps in Alaska’s vaccine delivery. Strategies for quality improvement include augmenting reminder/recall efforts and enhancing access to care for non-AI/AN children of lower SES.