Geographic proximity to immunization providers and vaccine series completion among children ages 0–24 months

• Published in: Vaccine 2023-04, Vol.41 (17), p.2773-2780
• Main Authors: Freeman, Rain E., Leary, Cindy S., Graham, Jonathan M., Albers, Alexandria N., Wehner, Bekki K., Daley, Matthew F., Newcomer, Sophia R.
• Format: Article
• Language: English
• Subjects: Child; Child, Preschool; Childhood immunisations; Children; Children & youth; Combined vaccines; Commuting; Distance to care; Geography; Health care access; Humans; Immunisation services; Immunization; Infant; Infant, Newborn; Information systems; Investigations; Metropolitan areas; Models, Statistical; Primary care; Public health; Risk factors; Rural areas; Rural health; Travel; Urban areas; Vaccination; Vaccination barriers; Vaccination Coverage; Vaccines
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2023.03.025

•Over 90% of children in Montana live within 10 miles of an immunization provider.•Long distances had modest associations with not completing childhood vaccinations.•Immunization information systems provide opportunities to identify vaccination barriers. In the U.S., vaccination coverage is lower in rural versus urban areas. Spatial accessibility to immunization services has been a suspected risk factor for undervaccination in rural children. Our objective was to identify whether geographic factors, including driving distance to immunization providers, were associated with completion of recommended childhood vaccinations. We analyzed records from Montana’s immunization information system for children born 2015–2017. Using geolocated address data, we calculated distance in road miles from children’s residences to the nearest immunization provider. A multivariable log-linked binomial mixed model was used to identify factors associated with completion of the combined 7-vaccine series by age 24 months. Among 26,085 children, 16,503 (63.3%) completed the combined 7-vaccine series by age 24 months. Distance to the nearest immunization provider ranged from 0 to 81.0 miles (median = 1.7; IQR = 3.2), with the majority (92.1%) of children living within 10 miles of a provider. Long distances (>10 miles) to providers had modest associations with not completing the combined 7-vaccine series (adjusted prevalence ratio [aPR]: 0.97, 95% confidence interval [CI]: 0.96–0.99). After adjustment for other factors, children living in rural areas (measured by rural-urban commuting area) were significantly less likely to have completed the combined 7-vaccine series than children in metropolitan areas (aPR: 0.88, 95% CI: 0.85–0.92). Long travel distances do not appear to be a major barrier to childhood vaccination in Montana. Other challenges, including limited resources for clinic-based strategies to promote timely vaccination and parental vaccine hesitancy, may have greater influence on rural childhood vaccination.