A state health department-led RCT to improve adolescent immunization using the AFIX model

Purpose. CDC's AFIX (Assessment, Feedback, Incentives, and eXchange) program improves the provision of early childhood vaccines via brief quality improvement consultations with primary care providers. We sought to evaluate whether a modified AFIX program could also boost uptake of under-used adolescent vaccines, including human papillomavirus (HPV) vaccine.

Methods. The North Carolina Immunization Branch randomly selected 91 high-volume primary care clinics in North Carolina serving 107,443 adolescents ages 11-18. They randomly assigned clinics to receive no consultation or an in-person or webinar AFIX consultation focused on adolescent immunization. The state's immunization registry provided 5-month-post-intervention coverage data. In logistic regressions stratified for younger and older adolescents, we assessed coverage for: tetanus, diphtheria, and pertussis (Tdap); meningococcal vaccine; and HPV vaccine initiation.

Results. In-person AFIX consultations led to higher coverage among adolescents ages 11-12 for Tdap (OR=1.50, 95% CI, 1.36-1.65) and meningococcal vaccine (OR=1.22, 95% CI, 1.13-1.33), but not HPV vaccine. Webinar AFIX consultations led to higher coverage for Tdap and meningococcal vaccine as well as HPV vaccine (OR=1.12, 95% CI, 1.03-1.23). AFIX consultations did not affect “catch up” vaccination for adolescents ages 13-18. Both in-person and webinar consultations received high scores on participant satisfaction, but webinar consultations were more cost effective.

Conclusions. Webinar AFIX consultations were at least as effective as in-person consultations in modestly increasing vaccine coverage for adolescents ages 11-12. Using AFIX nationally to address low adolescent vaccination rates is promising, but the program needs improvements to have greater impact on HPV vaccine initiation and catch-up vaccination.