Seventy-one studies were included in this review, and 5 papers provided more information about included studies. Of the other studies considered for inclusion, 14 were ineligible due to study country or article language, 20 were ineligible due to unsuitable study type and 15 were ineligible due to lack of outcomes of interest
Please note, the number of studies and publications do not always correspond (e.g., a publication may include several studies or one study may be explained in several publications).
Studies Included (71)
Studies evaluating helmet laws from U.S. (60)
Auman KM, Kufera JA, Ballesteros MF, Smialek JE, Dischinger PC. Autopsy Study of Motorcyclist Fatalities: The Effect of the 1992 Maryland Motorcycle Helmet Use Law. American Journal of Public Health 2002;92(8):1352-1355.
Bavon A, Standerfer C. The Effect of the 1997 Texas Motorcycle Helmet Law on Motorcycle Crash Fatalities. Southern Medical Journal 2010;103(1):11-17.
Berkowitz A. Evaluation of state motorcycle helmet laws using the National Electronic Injury Surveillance System. Washington, D.C.: USDOT, National Highway Traffic Safety Administration; 1981 10/1981. Report No.: DOT HS-806-062.
Bledsoe G, Li G. Trends in Arkansas motorcycle trauma after helmet law repeal. Southern Medical Journal 2005;98(4):436-440.
Branas CC, Knudson MM. Helmet laws and motorcycle rider death rates. Accident Analysis & Prevention 2001;33(5):641-648.
Brooks E, Naud S, Shapiro S. Are youth-only motorcycle helmet laws better than none at all? American Journal of Forensic Medicine and Pathology 2010;31(2):5.
Chenier TC, Evans L. Motorcyclist fatalities and the repeal of mandatory helmet wearing laws. Accident Analysis & Prevention 1987;19(2):133-139.
Coben JH, Steiner CA, Miller TR. Characteristics of motorcycle-related hospitalizations: Comparing states with different helmet laws. Accident Analysis & Prevention 2007;39(1):190-196.
Dao H, Lee J, Kermani R, Minshall C, Eriksson E, Gross R, et al. Cervical spine injuries and helmet laws: a population-based study. The Journal of Trauma and Acute Care Surgery 2012;72(3):638-41.
De Wolf V. The effect of helmet law repeal on motorcycle fatalities: US Department of Transportation; National Highway Traffic Safety Administration; 1986. Report No.: DOT HS 807 065.
Dee TS. Motorcycle helmets and traffic safety. Journal of Health Economics 2009;28(2):398-412.
DOT WI. Wisconsin Motorcycle helmet law: A before and after study of helmet law repeal. Wisconsin: Wisconsin Department of Transportation; 1981.
Fleming NS, Becker ER. The impact of the Texas 1989 motorcycle helmet law on total and head-related fatalities, severe injuries, and overall injuries. Medical Care 1992;30(9):832-845.
French MT, Gumus G, Homer JF. Public policies and motorcycle safety. Journal of Health Economics 2009;28(4):831-838.
French M, Gumus G, Homer J. Motorcycle fatalities among out-of-state riders and the role of universal helmet laws. Social Science & Medicine 2012;75:9.
Gilbert H, Chaudhary, N, Solomon, M, Preusser, D, Cosgove, L. Evaluation of the reinstatement of the helmet law in Louisiana: National Highway Traffic Safety Administration; 2008 May 2008.
Graham J, Lee Y. Behavioral response to safety regulation. Policy Sciences 1986;19(3):253-273.
Hartunian NS, Smart CN, Willemain TR, Zador PL. The Economics of Safety Deregulation: Lives and Dollars Lost due to Repeal of Motorcycle Helmet Laws. Journal of Health Politics, Policy and Law 1983;8(1):76-98.
Ho E, Haydel M. Louisiana motorcycle fatalities linked to statewide helmet law repeal. The Journal of the Louisiana State Medical Society 2004;156(3):151-2, 154.
Hotz G, Cohn S, Popkin C, Ekeh P, Duncan R, Johnson EW, et al. The impact of a repealed motorcycle helmet law in Miami-Dade County. The Journal of Trauma 2002;52(3):469-474.
Houston DJ. Are helmet laws protecting young motorcyclists? Journal of Safety Research 2007a;38(3):329-336.
Houston DJ, Richardson LE. Motorcycle Safety and the Repeal of Universal Helmet Laws. American Journal of Public Health 2007b;97(11):2063-2069.
Houston DJ, Richardson LE. Motorcyclist fatality rates and mandatory helmet-use laws. Accident Analysis & Prevention 2008;40(1):200-208.
Koehler M. Evaluation of motorcycle safety helmet usage laws: Final report. College Station, TX: Texas A&M University; 1978. Report No.: Texas Traffic Safety Program Contract IAC 78-08-36-A-1-AA.
Kraus J, Peek C, McArthur D, Williams A. The effect of the 1992 California motorcycle helmet use law on motorcycle crash fatalities and injuries. JAMA 1994;272(19):1506-1511.
Kraus J, Peek C. The impact of two related prevention strategies on head injury reduction among nonfatally injured motorcycle riders, California, 1991-1993. Journal of Neurotrauma 1995;12(5):873-881.
Kyrychenko SY, McCartt AT. Florida's Weakened Motorcycle Helmet Law: Effects on Death Rates in Motorcycle Crashes. Traffic Injury Prevention 2006;7(1):55-60.
Lloyd LE, Lauderdale M, Betz TG. Motorcycle deaths and injuries in Texas: helmets make a difference. Texas Medicine 1987;83(4):30-33.
Lummis ML, Dugger C. Impact of the repeal of the Kansas Mandatory Motorcycle Helmet Law, 1975 to 1978: an executive summary. The EMT Journal 1981;5(4):254-259.
Lund AK, Williams AF, Womack KN. Motorcycle helmet use in Texas. Public Health Reports 1991;106(5):576-578.
Max W, Stark B, Root S. Putting a lid on injury costs: the economic impact of the California motorcycle helmet law. The Journal of Trauma 1998;45(3):550-556.
Mayrose J. The effects of a mandatory motorcycle helmet law on helmet use and injury patterns among motorcyclist fatalities. Journal of Safety Research 2008;39(4):429-432.
McGwin G, Whatley J, Metzger J, Valent F, Barbone F, Rue L. The effect of state motorcycle licensing laws on motorcycle driver mortality rates. The Journal of Trauma 2004;56(2):415-419.
McHugh TP, Raymond JI. Safety helmet repeal and motorcycle fatalities in South Carolina. The Journal of the South Carolina Medical Association 1985;81(11):588-590.
McSwain N, Willey A, Janke T. Impact of re-enactment of the motorcycle helmet law in Louisiana. Proceedings: American Association for Automotive Medicine Annual Conference 1985;29:425-446.
Mertz KJ, Weiss HB. Changes in motorcycle-related head injury deaths, hospitalizations, and hospital charges following repeal of Pennsylvania's mandatory motorcycle helmet law. American Journal of Public Health 2008;98(8):1464-1467.
Mock CN, Maier RV, Boyle E, Pilcher S, Rivara FP. Injury prevention strategies to promote helmet use decrease severe head injuries at a level I trauma center. The Journal of Trauma 1995;39(1):29-33.
Morris CC. Generalized linear regression analysis of association of universal helmet laws with motorcyclist fatality rates. Accident Analysis & Prevention 2006;38(1):142-147.
Mounce NB, Q; Hinshaw, W; Lund, AK; Wells, JK. The reinstated comprehensive motorcycle helmet law in Texas. Arlington, VA: Insurance Institute for Highway Safety; 1992.
Muelleman RL, Mlinek EJ, Collicott PE. Motorcycle crash injuries and costs: Effect of a reenacted comprehensive helmet use law. Annals of Emergency Medicine 1992;21(3):266-272.
Muller A. Florida's Motorcycle Helmet Law Repeal and Fatality Rates. American Journal of Public Health 2004;94(4):556-558.
NHTSA. A report to congress on the effect of motorcycle helmet use law repeal-a case for helmet use. Washington, D.C.: National Highway Safety Administration, US Department of Transportation; 1980.
O'Keeffe. Increased fatalities after motorcycle helmet law repeal: is it all because of lack of helmets? The Journal of Trauma 2007;63(5):1006-1009.
Paulsrude S, Kahl S, Klingberg G. An evaluation of Washington State's motorcycle safety law's effectiveness. Washington: Washington Department of Motor Vehicles; 1967.
Pickrell TM, and Starnes, M. . An analysis of motorcycle helmet use in fatal crashes. Washington, D.C.: National Highway Traffic Safety Administration, US Department of Transportation; 2008. Report No.: DOT HS 811-011.
Preusser DF, Hedlund, J.H. and Ulmer, R.G. Evaluation of motorcycle helmet law repeal in Arkansas and Texas. Washington, D.C.: National Highway Traffic Safety Administration, US Department of Transportation; 2000. Report No.: DOT HS 809 131.
Prinzinger J. The effect of the repeal of helmet use laws on motorcycle fatalities. Atlantic Economic Journal 1982;10(2):36-39.
Proscia N, Sullivan T, Cuff S, Nealon P, Atweh N, DiRusso S, et al. The effects of motorcycle helmet use between hospitals in states with and without a mandatory helmet law. Connecticut Medicine 2002;66(4):195-198.
Robertson L. An instance of effective legal regulation: motorcyclist helmet and daytime headlamp laws. Law & Society Review 1976;10(3):467-477.
Sass T, Zimmerman P. Motorcycle helmet laws and motorcyclist fatalities. Journal of Regulatory Economics 2000;18(3):195-215.
Scholten DJ, Glover JL. Increased mortality following repeal of mandatory motorcycle helmet law. Indiana Medicine 1984;77(4):252-255.
Sosin Dm SJJ. Motorcycle helmet—use laws and head injury prevention. JAMA 1992;267(12):1649-1651.
Stolzenberg L, D'Alessio SJ. "Born to Be Wild": The effect of the repeal of Florida's mandatory motorcycle helmet-use law on serious injury and fatality rates. Evaluation Review 2003;27(2):131-150.
Struckman-Johnson C, Ellingstad V. Impact of motorcycle helmet law repeal in South Dakota 1976-79: Final report. Washington, DC; 1980. Report No.: DOT-HS-9-02130.
Turner P, Hagelin C. Florida motorcycle helmet use observational survey and trend analysis. Tampa, FL: Center for Urban Transportation Research, University of South Florida; 2004. Report No.: BC 353 RPWO #36.
Ulmer R, and Preusser, DF. Evaluation of the repeal of motorcycle helmet laws in Kentucky and Louisiana. Washington, D.C.: National Highway Traffic Safety Administration; 2003. Report No.: DOT HS 809 530.
Ulmer R, Shabanova-Northrup V. Evaluation of the repeal of the all-rider motorcycle helmet law in Florida. Washington D.C.: National Highway Traffic Safety Administration; 2005. Report No.: DOT HS 809 849.
Watson GS, Zador PL, Wilks A. The repeal of helmet use laws and increased motorcyclist mortality in the United States, 1975-1978. American Journal of Public Health 1980;70(6):579-585.
Weiss H, Agimi Y, Steiner C. Youth motorcycle-related brain injury by state helmet law type: United States, 2005-2007. Pediatrics 2010;126(6):1149-1155.
Williams A, Williams M, Ginsburg P, Burchman. Motorcycle helmet use in relation to legal requirements. Accident Analysis & Prevention 1979;11(4):271-273.
Studies evaluating helmet laws from outside U.S. (11)
Chiu WT KC, Hung CC, Chen M. The effect of the Taiwan motorcycle helmet use law on head injuries. American Journal of Public Health 2000;90(5):793-796.
Ferrando J, Plaséncia A, Orós M, Borrell C, Kraus JF. Impact of a helmet law on two wheel motor vehicle crash mortality in a southern European urban area. Injury Prevention 2000;6(3):184-188.
Foldvary L, Lane J. The effect of compulsory safety helmets on motor-cycle accident fatalities. Australian Road Research 1964;September:18.
Grima FG, Ontoso IA, Ontoso EA. Helmet Use by Drivers and Passengers of Motorcycles in Pamplona (Spain), 1992. European Journal of Epidemiology 1995;11(1):87-89.
La Torre G, Van Beeck E, Bertazzoni G, Ricciardi W. Head injury resulting from scooter accidents in Rome: differences before and after implementing a universal helmet law. The European Journal of Public Health 2007;17(6):607-611.
Nurchi GC, Golino P, Floris F, Meleddu V, Coraddu M. Effect of the law on compulsory helmets in the incidence of head injuries among motorcyclists. Journal of Neurosurgical Sciences 1987;31(3):141-143.
Servadei F, Begliomini C, Gardini E, Giustini M, Taggi F, Kraus J. Effect of Italy's motorcycle helmet law on traumatic brain injuries. Injury Prevention 2003;9(3):257-260.
Singh S, Robson S, Toomath J. Traffic research report: Compulsory safety helmet legislation and motor cyclist accidents. Wellington, New Zealand: Traffic Research Section, Road Transport Division, Ministry of Transport; 1975a.
Singh C, Robson S, Toomath J. Report NO. 9: Motorcycle helmet and headlamp checks 1973. Wellington, New Zealand: Ministry of Transport: Road Transport Division; 1975b.
Taggi F. Safety helmet law in Italy. The Lancet 1988;331(8578):182.
Tsai M-C, Hemenway D. Effect of the mandatory helmet law in Taiwan. Injury Prevention 1999;5(4):290-291.
Studies providing additional information for already included studies (implementation, applicability, generalizability) (5)
Bledsoe G, Schexnayder S, Carey M, Dobbins W, Gibson W, Hindman J, et al. The negative impact of the repeal of the Arkansas motorcycle helmet law. The Journal of Trauma 2002;53(6):1078-86.
Branas CC, Knudson MM. State helmet laws and motorcycle rider death rates. LDI Issue Brief 2001;7(1):1-4.
Dare CE, Owens, J.C., Krane, S. Impact of motorcycle helmet usage in Colorado. Washington, D.C.: National Highway Traffic Safety Administration, US Department of Transportation; 1978. Report No.: DOT HS 803680.
Kraus J, Peek C, Williams A. Compliance with the 1992 California motorcycle helmet use law. American Journal of Public Health 1995;85(1):96-99.
Peek-Asa C, Kraus JF. Estimates of Injury Impairment After Acute Traumatic Injury in Motorcycle Crashes Before and After Passage of a Mandatory Helmet Use Law. Annals of Emergency Medicine 1997;29(5):630-636.
Studies Excluded (49)
Low or middle income country or non-English language (14)
Asogwa SE. The crash helmet legislation in Nigeria: a before-and-after study. Accident Analysis & Prevention 1980;12:213-216.
De Andrade SM, Soares DA, Matsuo T, Lopes C, Liberatti B, Iwakura MLH. Road injury-related mortality in a medium-sized Brazilian city after some preventive interventions. Traffic Injury Prevention 2008;9(5):450-455.
Elia SMHRM. A question of safety : a preliminary study : a critique and proposal for study of motor cycle helmet use in Khon Kaen, Thailand. [St. Lucia, Qld.]; 1999.
Espitia-Hardeman V, Velez L, Gutierrez-Martinez MI, Espinosa-Vallin R, Concha-EAstman A. [Impact of interventions directed toward motorcyclist death prevention in Cali, Colombia: 1993-2001]. Salud Publica de Mexico 2008;50(Suppl 1):S69-77.
Falope IA. Motorcycle accidents in Nigeria. A new group at risk. West African Journal of Medicine 1991;10(2):187-189.
Ichikawa M, Chadbunchachai W, Marui E. Effect of the helmet act for motorcyclists in Thailand. Accident Analysis & Prevention 2003;35:183-189.
La Torre G. [Epidemiology of scooter accidents in Italy: the effectiveness of mandatory use of helmets in preventing incidence and severity of head trauma]. Recenti Progressi in Medicina 2003;94(1):1-4.
Law TH, Noland RB, Evans AW. Factors associated with the relationship between motorcycle deaths and economic growth. Accident Analysis & Prevention 2009;41(2):234-240.
Liberatti CLB, Andrade SM, Soares DA. The new Brazilian traffic code and some characteristics of victims in southern Brazil. Injury Prevention 2001;7:190-193.
Marchi AG, Messi G, Porebski E, Loschi L. [Evaluation of the usefulness of the motorcycle helmet in adolescents in Trieste]. Minerva Pediatrica 1989;41(6):329-333.
Panichaphongse V, Watanakajorn T, Kasantikul V. Effects of helmet-use law on death from motorcycle accidents. Journal of Medical Association Thailand 1995;78(10):521-525.
Passmore J, Tu NTH, Luong MA, Chinh ND, Nam NP. Impact of mandatory motorcycle helmet wearing legislation on head injuries in Viet Nam: results of a preliminary analysis. Traffic Injury Prevention 2010;11:202-206.
Supramaniam V, van Belle G, Sung JFC. Fatal motorcycle accidents and helmet laws in Peninsular Malaysia. Accident Analysis & Prevention 1984;16(3):157-162.
Tributsch W, Rabl W, Ambach E. [Fatal accidents of motorcycle riders. Comparison of the craniocervical injury picture before and following introduction of the legally sanctioned protective helmet rule]. Beitrage zur Gerichtlichen Medizin 1989;47:625-630.
Unsuitable study type (review, commentary, conference abstract) (20)
Adams J. Public safety legislation and the risk compensation hypothesis: the example of motorcycle helmet legislation. Environment and Planning C: Government and Policy 1983;1:193-230.
Balmer H. Analysis of the mandatory motorcycle helmet issue: Governor's Traffic Safety Council 1977.
Berkowitz A. The effect of the motorcycle helmet usage on head injuries and the effect of usage laws on helmet wearing rates. NHTSA-US Department of Transportation; 1979.
Bledsoe G. Arkansas and the motorcycle helmet law. The Journal of the Arkansas Medical Society 2004;100(12):430-433.
Espitia V, Concha-Eastman A, Espinosa R, Gutierrez M. Characteristics of motorcycle drivers deaths after the implementation of a compulsory law for helmet use. In: 6th World Conference on Injury Prevention and Control. Ontario, Canada; 2002.
GAO. Highway safety: motorcycle helmet laws save lives and reduce costs to society. Washington, D.C.: US General Accounting Office; 1991.
Knudson MM, Schermer C, Speetzen L. Motorcycle helmet laws: every surgeon's responsibility. Journal of the American College of Surgeons 2004;199(2):261-264.
Kruse T, Nordentoft, EL, Weeth, R. The effect of mandatory crash helmet use for moped riders in Denmark. In: 22nd Annual Conference of the American Association for Automotive Medicine; 1978; Morton Grove, IL; 1978.
Lin D, Lin, PC. . Study on motorcycle traffic safety in Taiwan area. In: Third Conference of Road Engineering Association of Asia and Australasia; 1981; Taipei, Taiwan; 1981. p. 329-344.
Lin M-R, Kraus J. A review of risk factors and patterns of motorcycle injuries. Accident Analysis & Prevention 2009;41(4):710-722.
Lowenstein SR, Koziol McLain J, Glazner J. The Colorado motorcycle safety survey: public attitudes and beliefs. The Journal of Trauma 1997;42(6):1124-1128.
McSwain NE, Petrucelli E. Medical consequences of motorcycle helmet nonusage. The Journal of Trauma 1984;24(3):233-236.
McSwain NE, Belles A. Motorcycle helmets--medical costs and the law. The Journal of Trauma 1990;30(10):1189-97.
Mersky AE, M; Overfield, P; Melanson, S; et al. The effect of the repeal of the Pennsylvania helmet law on the severity of head and neck injuries sustained in motorcycle accidents. Annals of Emergency Medicine 2009;54(3):S94.
Muller A. Weakening of Florida's motorcycle helmet law: the first thirty months. In: 132nd American Public Health Association Annual Meeting; 2004a; Washington, D.C.; 2004a.
O'Neill B, Kyrychenko S. Use and misuse of motor-vehicle crash death rates in assessing highway-safety performance. Traffic Injury Prevention 2006;7(4):307-318.
Rollberg CA. The mandatory motorcycle helmet law issue in Arkansas: the cost of repeal. The Journal of the Arkansas Medical Society 1990;86(8):312-316.
Russo PK. Easy rider--hard facts: motorcycle helmet laws. The New England Journal of Medicine 1978;299(19):1074-1076.
Thoma T. National Highway Traffic Safety Administration (NHTSA) Notes: An analysis of motorcycle helmet use in fatal crashes. Annals of Emergency Medicine 2009;53(4):501-501.
Vaca F. Commentary: Motorcycle helmet law repeal: When will we learn … or truly care to learn? Annals of Emergency Medicine 2006;47(2):204-206.
Lack of outcomes of interest for effectiveness or incomplete data (15)
Chiu W-T. The motorcycle helmet law in Taiwan. JAMA 1995;274(12):941-942.
Chiu W-T, Huang S-J, Tsai S-H, Lin J-W, Tsai M-D, Lin T-J, et al. The impact of time, legislation, and geography on the epidemiology of traumatic brain injury. Journal of Clinical Neuroscience 2007;14(10):930-935.
Chiu W CSCCLTCY. Implementation of a motorcycle helmet law in Taiwan and traffic deaths over 18 years. JAMA 2011;306(3):267-268.
Dalkie H, Mulligan GWN. The impact of Bill 60: A study to evaluate the effectiveness of mandatory seat belt and motorcycle helmet use legislation in Manitoba. Manitoba, Canada: The University of Manitoba; 1985.
Heilman DR, Weisbuch JB, Blair RW, Graf LL. Motorcycle-related trauma and helmet usage in North Dakota. Annals of Emergency Medicine 1982;11(12):659-664.
Iowa DOT. Iowa motorcycle accidents 1974-1976: Iowa Department of Transportation, Office of Safety Programs; 1978.
Jamieson KG, Kelly D. Crash helmets reduce head injuries. Medical Journal of Australia 1973;2(17):806-809.
Muller A. Evaluation of the costs and benefits of motorcycle helmet laws. American Journal of Public Health 1980;70(6):586-592.
Offner PJ, Rivara FP, Maier RV. The impact of motorcycle helmet use. The Journal of Trauma and Acute Care Surgery 1992;32(5):636-642.
Peek-Asa C, McArthur DL, Kraus JF. The prevalence of non-standard helmet use and head injuries among motorcycle riders. Accident Analysis & Prevention 1999;31(3):229-233.
Pileggi C, Bianco A, Nobile CGA, Angelillo IF. Risky behaviors among motorcycling adolescents in Italy. The Journal of Pediatrics 2006;148(4):527-532.
Richardson H. A motorcycle safety helmet study. Washington, D.C.: National Highway Traffic and Safety Administration; 1974. Report No.: DOT HS-801 137.
Schuchmann JA. Motorcycle helmet laws--legislative frivolity or common sense. Texas Medicine 1988;84(2):34-35.
Tsauo J-Y, Hwang J-S, Chiu W-T, Hung C-C, Wang J-D. Estimation of expected utility gained from the helmet law in Taiwan by quality-adjusted survival time. Accident Analysis & Prevention 1999;31(3):253-263.
Weisbuch JB. The prevention of injury from motorcycle use: Epidemiologic success, legislative failure. Accident Analysis & Prevention 1987;19(1):21-28.