title: Nonmedical exemptions from school immunization requirements: a systematic review.
abstract: We summarized studies describing the prevalence of, trends in, and correlates of nonmedical exemptions from school vaccination mandates and the association of these policies with the incidence of vaccine-preventable disease. We searched 4 electronic databases for empirical studies published from 1997 to 2013 to capture exemption dynamics and qualitatively abstracted and synthesized the results. Findings from 42 studies suggest that exemption rates are increasing and occur in clusters; most exemptors questioned vaccine safety, although some exempted out of convenience. Easier state-level exemption procedures increase exemption rates and both individual and community disease risk. State laws influence exemption rates, but policy implementation, exemptors' vaccination status, and underlying mechanisms of geographical clustering need to be examined further to tailor specific interventions.
authors.affiliation: Eileen Wang is with the Department of the History and Sociology of Science, University of Pennsylvania, Philadelphia. Jessica Clymer is with the School of Nursing, University of Pennsylvania. Cecilia Davis-Hayes is with the Columbia University College of Physicians and Surgeons, New York, NY. Alison Buttenheim is with the School of Nursing, the Leonard Davis Institute, and the Center for Public Health Initiatives, University of Pennsylvania.
authors.forename: Eileen
authors.initials: E
authors.lastname: Wang
authors.forename: Jessica
authors.initials: J
authors.lastname: Clymer
authors.forename: Cecilia
authors.initials: C
authors.lastname: Davis-Hayes
authors.forename: Alison
authors.initials: A
authors.lastname: Buttenheim
mesh_terms: D002648:Child; D006801:Humans; D017589:Immunization Programs / Q000706:statistics & numerical data*; D015995:Prevalence; D011640:Public Policy; D012572:School Health Services / Q000706:statistics & numerical data*; D016312:Treatment Refusal / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology