Effectiveness of a State Law Mandating Use of Bicycle Helmets among Children: An Observational Evaluation Dafna Kanny, PhD Richard A. Schieber, MD, MPH Vickie Pryor, RN, MPH Marcie-jo Kresnow, MS AJE 2001;154(11):
Learning Objectives Identify the scope of bicycle helmet use among children and state legislation Describe the effectiveness of a state law for bicycle helmet use among children Provide recommendation for such legislation
Bicycling in U.S. Children 5-14 Years ~28 million riders Pedal cyclist injury –200 deaths –100,000 ED visits Brain injury –125 deaths (65%) –20,000 ED visits (20%)
Helmet Use in U.S. Children 5-14 Years Helmets reduce risk by 69% -88% 50% own a helmet Only 25% always wear helmet
Bicycle Helmet Use Legislation Study Maryland, USA (Cote et al., 1993) Oregon, USA (Ni et al., 1997) Victoria, Australia (Cameron et al., 1994) Pre-Law 4% (1990) 25% (1994) 36% (1990) Post-Law 47% (1991) 49% (1995) 83% (1992)
Bicycle Helmet Use Legislation in the U.S. Only 18 states and ~80 cities have helmet laws
1997 Florida Law Children under of 67 counties adopt the law 3 counties legally “opted out”
Elementary School Observations in Florida, Four Counties Pre (1991): 5% helmeted Post (1992): 15% helmeted Intervention: –Education –Policy –Media promotion –Helmet distribution
Elementary School Observations in Florida, Duval County Pre (1996):13% helmeted Post (1998): 73% helmeted Intervention: –Education –Helmet distribution –Legislation
Purpose How well do Duval County results represent the state? How beneficial was the state law? Which counties have the greatest need for intervention?
Inclusion Criteria Any Florida public elementary school with: –Grades K-5 –No prohibition against cycling to school –At least one rider
Study Population 55/64 intervention counties with a law 3/3 control counties without a law Total 1,015/ 1,064 schools (95% response rate) Total 21,763 children (unit of analysis)
Observation Methods Spring 1999 Unobtrusive observations by school official of bicycle rack 1 day 1 time only Variables: –Bicycle helmet use, gender, race (W, B, O)
Helmet Use by Law Helmet (Outcome) Law (Exposed) + 16,907 (79.3) 4,406 (20.7) (32.9) 302 (67.1) Crude Prevalence Ratio (PR) = 2.4 ( ) 21,
Helmet Use by Gender Helmet Boys Girls 10,941 (77.5) 3,180 (22.5) 6,114 (80.0) 1,528 (20.0) 2 =18.7, df=1 p < ,121 7,642 Yes No
Helmet Use by Race Helmet White Black Other 13,274 (82.2) 2,880 (17.8) 1,893 (60.8) 1,220 (39.2) 1,888 (75.6) 608 (24.4) 2 =714.9, df=2 p < ,154 3,113 2,496 Yes No
Summary: Helmet Use by Law Crude 2.4 (2.1, 2.8) Adjusted 2.3 (2.0, 2.6) (Gender, Race) Prevalence Ratio (95% CI)
Conclusions Children from counties with a state bicycle helmet law were twice as likely to wear bicycle helmets Gender and race did not confound this relationship
Limitations Few covariates possible No pre-law data collected School policy and its enforcement were not reported sufficiently
Advantages Statewide survey, nearly all schools All elementary grades Observational, not self-reported Comparison group Gender and race also considered
Recommendations Encourage the implementation and evaluation of Healthy People 2010 objective: All 50 states should have laws requiring bicycle helmets for riders (Objective #15-24)