Organizational correlates of adolescent immunization: Findings of a state-wide study of primary care clinics in North Carolina

Objective: To analyze organizational correlates of immunization coverage among adolescents served by high-volume primary care providers in North Carolina. Methods: We randomly selected 91 clinics with at least 200 active records for patients ages 11-18 in the North Carolina Immunization Registry. For the 105,121 adolescents served by these clinics, we obtained immunization status for 6 vaccines, including human papillomavirus (HPV) vaccine (females only); meningococcal conjugate; and tetanus, diphtheria, and pertussis booster (Tdap). Results: Clinics specializing in pediatrics had higher coverage for meningococcal vaccine (OR. = 1.79, 95% CI: 1.25-2.55), Tdap vaccine (OR. = 1.22, 95% CI: 1.00-1.50), and childhood vaccines. However, pediatric clinics had lower coverage for HPV vaccine initiation (OR. = 0.70, 95% CI: 0.52-0.94). Other correlates, which varied by vaccine, included policies related to vaccine documentation and the age at which clinics recommended vaccines. Conclusion: Overall, adolescents were more likely to receive vaccines, except HPV vaccine, if they attended a pediatric clinic with supportive clinical policies.