Impact of addition of philosophical exemptions on childhood immunization rates.
BACKGROUND
Although incidence of vaccine-preventable diseases has decreased, states' school immunization requirements are increasingly challenged. Subsequent to a federal court ruling affecting religious immunization exemptions to school requirements, new legislation made philosophical immunization exemptions available in Arkansas in 2003-2004. This retrospective study conducted in 2006 describes the impact of philosophical exemption legislation in Arkansas.


METHODS
Arkansas Division of Health data on immunization exemptions granted were linked to Department of Education data for all school attendees (grades K through 12) during 2 school years before the legislation (2001-2002 and 2002-2003 [Years 1 and 2, respectively]) and 2 years after philosophical exemptions were available (2003-2004 and 2004-2005 [Years 3 and 4, respectively]). Changes in numbers, types, and geographic distribution of exemptions granted are described.


RESULTS
The total number of exemptions granted increased by 23% (529 to 651) from Year 1 to 2; by 17% (total 764) from Year 2 to 3 after philosophical exemptions were allowed; and by another 50% from Year 3 to 4 (total 1145). Nonmedical exemptions accounted for 79% of exemptions granted in Years 1 and 2, 92% in Year 3, and 95% in Year 4. Importantly, nonmedical exemptions clustered geographically, suggesting concentrated risks for vaccine-preventable diseases in Arkansas communities.


CONCLUSIONS
Legislation allowing philosophical exemptions from school immunization requirements was linked to increased numbers of parents claiming nonmedical exemptions, potentially causing an increase in risk for vaccine-preventable diseases. Continued education and dialogue are needed to explore the balance between individual rights and the public's health.
Thompson
Joseph W
JW
Arkansas Center for Health Improvement, Department of Pediatrics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72201, USA. thompsonjosephw@uams.edu
Tyson
Shirley
S
Card-Higginson
Paula
P
Jacobs
Richard F
RF
Wheeler
J Gary
JG
Simpson
Pippa
P
Bost
James E
JE
Ryan
Kevin W
KW
Salmon
Daniel A
DA
D000293:Adolescent; D001131:Arkansas; D002648:Child; D002675:Child, Preschool; D003140:Communicable Disease Control / Q000331:legislation & jurisprudence*; D005260:Female; D006801:Humans; D017589:Immunization Programs / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D008297:Male; D037141:Mandatory Programs; D033282:Parental Consent; D010290:Parents / Q000523:psychology; D012068:Religion and Medicine; D012570:School Admission Criteria; D016312:Treatment Refusal / Q000331:legislation & jurisprudence*