School-Located Influenza Vaccinations: A Randomized Trial.

OBJECTIVE Assess impact of offering school-located influenza vaccination (SLIV) clinics using both Web-based and paper consent upon overall influenza vaccination rates among elementary school children. METHODS We conducted a cluster-randomized trial (stratified by suburban/urban districts) in upstate New York in 2014-2015. We randomized 44 elementary schools, selected similar pairs of schools within districts, and allocated schools to SLIV versus usual care (control). Parents of children at SLIV schools were sent information and vaccination consent forms via e-mail, backpack fliers, or both (depending on school preferences) regarding school vaccine clinics. Health department nurses conducted vaccine clinics and billed insurers. For all children registered at SLIV/control schools, we compared receipt of influenza vaccination anywhere (primary outcome). RESULTS The 44 schools served 19 776 eligible children in 2014-2015. Children in SLIV schools had higher influenza vaccination rates than children in control schools county-wide (54.1% vs 47.4%, P < .001) and in suburban (61.9% vs 53.6%, P < .001) and urban schools (43.9% vs 39.2%; P < .001). Multivariate analyses (controlling for age, grade, vaccination in previous season) confirmed bivariate findings. Among parents who consented for SLIV, nearly half of those notified by backpack fliers and four-fifths of those notified by e-mail consented online. In suburban districts, SLIV did not substitute for primary care influenza vaccination. In urban schools, some substitution occurred. CONCLUSIONS SLIV raised seasonal influenza vaccination rates county-wide and in both suburban and urban settings. SLIV did not substitute for primary care vaccinations in suburban settings where pediatricians often preorder influenza vaccine but did substitute somewhat in urban settings.