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.