Motorcycle helmets save lives, but not limbs: a National Trauma Data Bank analysis of functional outcomes after motorcycle crash

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

Novelty helmet use and motorcycle rider fatality

OBJECTIVES

To compare the risk of fatal injury across helmet types among collision-involved motorcyclists.

METHODS

We used data from a cohort of motorcyclists involved in police-reported traffic collisions. Eighty-four law enforcement agencies in California collected detailed information on helmet and rider characteristics during collision investigations in June 2012 through July 2013. Multiply-adjusted risk ratios were estimated with log-binomial regression.

RESULTS

The adjusted fatal injury risk ratio for novelty helmets was 1.95 (95% CI 1.11-3.40, p 0.019), comparing novelty helmets with full-face helmets. The risk ratios for modular, open-face, and half-helmets, compared with full-face helmets, were not significant.

CONCLUSIONS

A more complete understanding of the inadequacy of novelty helmets can be used in educational and law enforcement countermeasures to improve helmet use among motorcycling populations in California and other US states. Law enforcement approaches to mitigating novelty helmet use would seem attractive given that novelty helmets can be visually identified by law enforcement officers with sufficient training.

The Impact of Michigan's Partial Repeal of the Universal Motorcycle Helmet Law on Helmet Use, Fatalities, and Head Injuries

OBJECTIVES

To evaluate the impact of the partial repeal of Michigan's universal motorcycle helmet law on helmet use, fatalities, and head injuries.

METHODS

We compared helmet use rates and motorcycle crash fatality risk for the 12 months before and after the April 13, 2012, repeal with a statewide police-reported crash data set. We linked police-reported crashes to injured riders in a statewide trauma registry. We compared head injury before and after the repeal. Regression examined the effect of helmet use on fatality and head injury risk.

RESULTS

Helmet use decreased in crash (93.2% vs 70.8%; P < .001) and trauma data (91.1% vs 66.2%; P < .001) after the repeal. Although fatalities did not change overall (3.3% vs 3.2%; P = .87), head injuries (43.4% vs 49.6%; P < .05) and neurosurgical intervention increased (3.7% vs 6.5%; P < .05). Male gender (adjusted odds ratio [AOR] = 1.65), helmet nonuse (AOR = 1.84), alcohol intoxication (AOR = 11.31), intersection crashes (AOR = 1.62), and crashes at higher speed limits (AOR = 1.04) increased fatality risk. Helmet nonuse (AOR = 2.31) and alcohol intoxication (AOR = 2.81) increased odds of head injury.

CONCLUSIONS

Michigan's helmet law repeal resulted in a 24% to 27% helmet use decline among riders in crashes and a 14% increase in head injury.

Factors associated with the use of motorcycle helmets in two Colombian cities

The aim of this study was to identify the prevalence and some characteristics associated with the use of motorcycle helmets in two Colombian cities. The researcher used quantitative and qualitative techniques. The prevalence of the use of a motorcycle helmet among motorcyclists was greater in Ibague (98.1%) than in Valledupar (82.4%); among passengers in the city of Valledupar, it did not reach 2%. Men were 2.1 times more likely to wear helmets than women (IC 95:1.6-2.7). Using qualitative techniques, the factors explaining the reasons for use/non-use of helmets (being hygienic, climatic, esthetic and safety reasons) were identified for Valledupar. The use of the helmet is a protective measure in the event of traffic accidents; however, the prevalence of usage is not ideal. It is important for traffic and health authorities as well as the civil society to organize, in order to design and implement measures aimed at strengthening the use of this road safety gear.

Observation of motorcycle helmet use rates in Michigan after partial repeal of the universal motorcycle helmet law

Motorcycle crashes result in a significant health burden, including many fatal injuries and serious non-fatal head injuries. Helmets are highly effective in preventing such trauma, and jurisdictions that require helmet use of all motorcyclists have higher rates of helmet use and lower rates of head injuries among motorcyclists. The current study examines helmet use and characteristics of helmeted operators and their riding conditions in Michigan, following a weakening of the state's universal motorcycle helmet use law in April 2012. Data on police-reported crashes occurring during 2012-14 and from a stratified roadside observational survey undertaken in Southeast Michigan during May-September 2014 were used to estimate statewide helmet use rates. Observed helmet use was more common among operators of sports motorcycles, on freeways, and in the morning, and least common among operators of cruisers, on minor arterials, and in the afternoon. The rate of helmet use across the state was estimated at 75%, adjusted for roadway type, motorcycle class, and time of day. Similarly, the helmet use rate found from examination of crash records was 73%. In the observation survey, 47% of operators wore jackets, 94% wore long pants, 54% wore boots, and 80% wore gloves. Protective clothing of jackets and gloves was most often worn by sport motorcycle operators and long pants and boots most often by riders of touring motorcycles. Findings highlight the much lower rate of helmet use in Michigan compared with states that have a universal helmet use law, although the rate is higher than observed in many states with partial helmet laws. Targeted interventions aimed at specific groups of motorcyclists and situations where helmet use rates are particularly low should be considered to increase helmet use.

Trends in helmet use by motorcycle riders in the decades following the repeal of mandatory helmet laws

Several US states repealed universal motorcycle helmet laws in the 1990s and 2000s. The purpose of this study was to examine national trends in helmet use among adult trauma patients with motorcycle-related injuries. We hypothesized that motorcycle helmet use declined over time. We retrospectively analyzed the National Trauma Data Bank's National Sample Program for 2003-2010. We also obtained data on US motorcycle fatalities reported in the Fatality Analysis Reporting System and population data from the U.S. Census Bureau to calculate motorcycle-related fatality rates over time. A total of 255,914 patients met inclusion criteria, of whom 148,524 (58%) were helmeted. During the study period, helmet use increased from 56% in 2003 to 60% in 2010 (p < 0.001). However, motorcycle-related fatality rates also increased in states with and without universal helmet laws. Nationally, rates of helmet use have increased. However, fatalities due to motorcycle crashes have also increased during the same period.

Motorcycle helmet use and the risk of head, neck, and fatal injury: Revisiting the Hurt Study

Most studies find strong evidence that motorcycle helmets protect against injury, but a small number of controversial studies have reported a positive association between helmet use and neck injury. The most commonly cited paper is that of Goldstein (1986). Goldstein obtained and reanalyzed data from the Hurt Study, a prospective, on-scene investigation of 900 motorcycle collisions in the city of Los Angeles. The Goldstein results have been adopted by the anti-helmet community to justify resistance to compulsory motorcycle helmet use on the grounds that helmets may cause neck injuries due to their mass. In the current study, we replicated Goldstein's models to understand how he obtained his unexpected results, and we then applied modern statistical methods to estimate the association of motorcycle helmet use with head injury, fatal injury, and neck injury among collision-involved motorcyclists. We found Goldstein's analysis to be critically flawed due to improper data imputation, modeling of extremely sparse data, and misinterpretation of model coefficients. Our new analysis showed that motorcycle helmets were associated with markedly lower risk of head injury (RR 0.40, 95% CI 0.31-0.52) and fatal injury (RR 0.44, 95% CI 0.26-0.74) and with moderately lower but statistically significant risk of neck injury (RR 0.63, 95% CI 0.40-0.99), after controlling for multiple potential confounders.

Road traffic injury among child motorcyclists in Vientiane Capital, Laos: a cross-sectional study using a hospital-based injury surveillance database

This study investigated the distribution of motorcyclists, including drivers and passengers, who were involved in road traffic crashes and admitted to hospital in Vientiane Capital, Laos. The focus was on child motorcycle drivers and passengers under 15 years. A hospital-based injury surveillance database in Vientiane Capital was used. The surveillance was performed in two hospitals. From 1 September to 31 December 2009, 3968 patients were admitted to the participating hospitals with road traffic injuries. Patients under 15 years accounted for 10.8% (427/3968). The majority of patients under 15 years were motorcycle drivers or passengers (71.7%, 306/427). Child motorcyclists including drivers and passengers were less likely to wear a helmet than adults (adjusted odds ratio [OR], 0.3, 95% confidence interval [CI], 0.2-0.5, for children 10-14 years; adjusted OR: 0.1, 95% CI, 0.05-0.4, for children under 10 years). It is suggested that stricter regulation enforcement for child motorcycle drivers and passengers may be needed. In addition, barriers against wearing helmets for motorcycle drivers and passengers in Laos should also be examined in further studies.

Risky behaviors and helmet use among young adolescent motorcyclists in Southern Thailand

BACKGROUND

In Thailand, road traffic injuries are the leading cause of death for youth ages 15-19 years, with 80% of the injuries and deaths from motorcycle accidents.

OBJECTIVES

To determine the prevalence of child and young adolescent motorcyclists in Hat Yai municipality and their risk behaviors.

METHOD

A cross-sectional study was conducted between June 2011 and March 2012 in which 2,471 students, ages 8 to 18 years, were recruited from 9 primary and secondary schools in Hat Yai municipality. The questionnaire included questions on being a motorcycle rider or passenger, risky behaviors, and helmet use while riding.

RESULTS

Of the total, 1,573 (63.7%) were riders and 898 (36.3%) were pillion passengers. The majority of the riders younger than 15 years rode their motorcycle mainly only in narrow streets for a short trip. Only 30% of the riders wore a helmet every time they rode a motorcycle. About 10% of the participants riding or a passenger on a motorcycle had consumed alcohol at least once before riding their motorcycle. Multiple logistic regression analysis found that motorcycle injuries were significantly associated with speeds greater than 60 km/h, not wearing a helmet while riding, and alcohol consumption before riding (odds ratios 1.63, 1.59, and 3.09, respectively).

CONCLUSION

Nearly two thirds of young adolescents in Hat Yai municipality were motorcycle riders. These young adolescents were at risk of traffic injuries because more than 50% of them had ridden at high speed or not worn a helmet while riding, and some of them had consumed alcohol before riding.

Comparison of Injury Severity Between Moped and Motorcycle Crashes: A Finnish Two-Year Prospective Hospital-Based Study

BACKGROUND AND AIMS

The coverage of the official statistics is poor in motorcycle and moped accidents. The aim of this study was to analyze the severity of motorcycle and moped crashes, and to define the degree of under-reporting in official statistics.

MATERIAL AND METHODS

All first attendances due to an acute motorcyclist or moped driver injury registered in the emergency department between June 2004 and May 2006 were analyzed. The severity of the injuries was classified using the Abbreviated Injury Scale score and the New Injury Severity Score. The hospital injury data were compared to the traffic accident statistics reported by the police and compiled and maintained by Statistics Finland.

RESULTS

A total of 49 motorcyclists and 61 moped drivers were involved in crashes, leading to a total of 94 and 109 injuries, respectively. There were slightly more vertebral and midfoot fractures among motorcyclists than among moped drivers (p = 0.038 and 0.016, respectively). No significant differences were found between the severity (maximum Abbreviated Injury Scale and median New Injury Severity Scores) of the motorcycle and moped crashes. There was no in-hospital mortality. The degree of agreement (overlap) between the hospital dataset and the official statistics was 32%. The rate of under-reporting was 68%.

CONCLUSIONS

According to the maximum Abbreviated Injury Scale and New Injury Severity Scores, the injury severity was equal for motorcycle and moped crashes. The degree of agreement between the hospital dataset and the official statistics was 32%.

Motorised two-wheeler crash and helmets: injury patterns, severity, mortality and the consequence of gender bias

BACKGROUND

India records the maximum number of deaths from motorised two-wheeler vehicle (MTV) accidents in the world with mandatory helmet laws for males but not females. This study was designed to investigate injury patterns, severity, mortality, and helmet usage among hospital admitted victims of a MTV crash with a paired subgroup analyses on female victims.

METHODS

Hospital trauma registry from January 2011 to July 2012 for all adult victims of a MTV crash was analysed for outcomes of mortality, serious head injury, severe facial injury, and cervical spine injury while adjusting for age, gender, use of alcohol/drugs, injury severity score, and presence of shock by multivariable logistic regression model. Groups of helmeted victims (HV) and nonhelmeted victims (NHV) were identified.

RESULTS

A total of 2,718 victims were included. HV suffered maximum injuries to the lower extremity (29.04 %) and had reduced adjusted odds of death (odds ratio (OR) 0.65; 95 % confidence interval (CI) 0.48-0.86), serious head injury (OR 0.34; CI 0.26-0.45), cervical spine injury (OR 0.74; CI 0.54-1.06), and serious facial injury (OR 0.87; CI 0.57-1.26) compared with NHV who suffered maximum injuries to the head (24.49 %). Compliance with helmet use was 52.91 and 7.94 % among males and females respectively. A total of 224 pairs of male driver and female pillion involved in same MTV crash were identified, and the predominantly helmeted male had reduced odds of death (OR 0.44; CI 0.21-0.84) and severe head injury (OR 0.42; CI 0.24-0.72) compared with overwhelmingly nonhelmeted females.

CONCLUSIONS

Helmet laws must be strictly enforced, and society should think about the cost being born by its fairer counterpart by the gender-based differential law.

Influence of type of helmet on facial trauma in motorcycle accidents

The mandatory use of helmets by motorcyclists has lowered the incidence of facial trauma, but we know little about the effects of different models of helmet on such injuries. We aimed to find out how different types of helmet affect facial injuries. We collected retrospective data from the medical records of 157 patients treated in a trauma centre in metropolitan São Paulo between January and December 2011. Patients wearing open-face helmets were twice as likely to require an operation as those wearing full-face helmets. The type of helmet is strongly associated with the treatment required.

Systematically Tabulated Outcomes Research Matrix (STORM): a methodology to generate research hypotheses

BACKGROUND

Here we describe the Systematically Tabulated Outcomes Research Matrix (STORM) method to generate research questions from pre-existing databases with the aim of improving patient outcomes.

MATERIALS AND METHODS

STORM can be applied to a database by tabulating its variables into a matrix of independent variables (y-axis) and dependent variables (x-axis) and then applying each unique pairing of an independent and dependent variable to a patient population to generate potentially meaningful research questions.

RESULTS

To demonstrate this methodology and establish proof-of-principle, STORM was applied on a small scale to the National Trauma Data Bank and generated at least seven clinically meaningful research questions.

CONCLUSION

When coupled with rigorous clinical judgment, the STORM approach complements the traditional method of hypothesis formation and can be generalized to outcomes research using registry databases across different medical specialties.

Influence of the National Trauma Data Bank on the study of trauma outcomes: is it time to set research best practices to further enhance its impact?

BACKGROUND

Risk-adjusted analyses are critical in evaluating trauma outcomes. The National Trauma Data Bank (NTDB) is a statistically robust registry that allows such analyses; however, analytical techniques are not yet standardized. In this study, we examined peer-reviewed manuscripts published using NTDB data, with particular attention to characteristics strongly associated with trauma outcomes. Our objective was to determine if there are substantial variations in the methodology and quality of risk-adjusted analyses and therefore, whether development of best practices for risk-adjusted analyses is warranted.

STUDY DESIGN

A database of all studies using NTDB data published through December 2010 was created by searching PubMed and Embase. Studies with multivariate risk-adjusted analyses were examined for their central question, main outcomes measures, analytical techniques, covariates in adjusted analyses, and handling of missing data.

RESULTS

Of 286 NTDB publications, 122 performed a multivariable adjusted analysis. These studies focused on clinical outcomes (51 studies), public health policy or injury prevention (30), quality (16), disparities (15), trauma center designation (6), or scoring systems (4). Mortality was the main outcome in 98 of these studies. There were considerable differences in the covariates used for case adjustment. The 3 covariates most frequently controlled for were age (95%), Injury Severity Score (85%), and sex (78%). Up to 43% of studies did not control for the 5 basic covariates necessary to conduct a risk-adjusted analysis of trauma mortality. Less than 10% of studies used clustering to adjust for facility differences or imputation to handle missing data.

CONCLUSIONS

There is significant variability in how risk-adjusted analyses using data from the NTDB are performed. Best practices are needed to further improve the quality of research from the NTDB.

The frequency and predictors of helmet use among Iranian motorcyclists: A quantitative and qualitative study

OBJECTIVE

This study examines the rate of helmet use and identifies barriers and facilitators of wearing helmets among Iranian motorcyclists. A mixed-method approach was used, including a structured seasonal survey with specific observations of a random sample of 6010 riders and qualitative methods that included 29 in-depth interviews and seven focus groups (n=31).

RESULTS

Only 10% of motorcyclists wear a standard helmet while riding. However, another 23% of motorcyclists used non-standard or partial helmets that covered only part of the head and do not prevent head trauma injuries effectively. We observed only 2 of 264 child passengers and 22 of 1951 adult passengers wearing helmets. Almost no one used protective pants or clothing made to be more visible in traffic. Themes emerged from qualitative interviews and were grouped into three main categories: (1) helmet characteristics; (2) social and cultural factors; and (3) personal and psychological factors.

CONCLUSION

Overall, the motorcyclists in our study believed that wearing a safety helmet protects them against serious injuries or death during a crash; however, only a small percentage of the motorcyclists used safety helmets. National intervention programs addressing motorcycle safety should aim to overcome barriers to and promote facilitators of helmet use, including providing inexpensive standard helmets, banning manufacturing/using unsafe partial or dummy helmets, as well as enforcing helmet use on a consistent basis.