The cost-effectiveness of compulsory bicycle helmets in New Zealand

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.

Cost-effectiveness of mandatory bicycle helmet use to prevent traumatic brain injuries and death

Background

Traumatic brain injury (TBI) is the main cause of mortality and severe morbidity in cyclists admitted to Dutch emergency departments (EDs). Although the use of bicycle helmets is an effective way of preventing TBI, this is uncommon in the Netherlands. An option to increase its use is through a legal enforcement. However, little is known about the cost-effectiveness of such mandatory use of helmets in the Dutch context.

The current study aimed to assess the cost-effectiveness of a law that enforces helmet use to reduce TBI and TBI-related mortality.

Methods

The cost-effectiveness was estimated through decision tree modelling. In this study, wearing bicycle helmets enforced by law was compared with the current situation of infrequent voluntary helmet use. The total Dutch cycling population, consisting of 13.5 million people, was included in the model. Model data and parameters were obtained from Statistics Netherlands, the National Road Traffic Database, Dutch Injury Surveillance System, and literature. Effects included were numbers of TBI, death, and disability-adjusted life years (DALY). Costs included were healthcare costs, costs of productivity losses, and helmet costs. Sensitivity analysis was performed to assess which parameter had the largest influence on the incremental cost-effectiveness ratio (ICER).

Results

The intervention would lead to an estimated reduction of 2942 cases of TBI and 46 deaths.

Overall, the incremental costs per 1) death averted, 2) per TBI averted, and 3) per DALY averted were estimated at 1) € 2,002,766, 2) € 31,028 and 3) € 28,465, respectively. Most favorable were the incremental costs per DALY in the 65+ age group: € 17,775.

Conclusions

The overall costs per DALY averted surpassed the Dutch willingness to pay threshold value of € 20,000 for cost-effectiveness of preventive interventions. However, the cost per DALY averted for the elderly was below this threshold, indicating that in this age group largest effects can be reached. If the price of a helmet would reduce by 20%, which is non-hypothetical in a situation of large-scale purchases and use of these helmets, the introduction of this regulation would result in an intervention that is almost cost-effective in all age groups.

Economic evaluations of strategies to prevent sports and recreational injury among children and adolescents: a systematic review

Objective

To identify, summarise and critically assess studies reporting costs and consequences of sport and recreation injury prevention strategies among children and adolescents.

Design

Systematic review.

Methods and data sources

We searched MEDLINE (Ovid), EMBASE, CINAHL, Pubmed, Econlit and SPORTDiscus and PEDE. Included studies were peer reviewed full economic evaluations or cost analyses of sport/recreation injury prevention among children and adolescents≤18 years of age. The Pediatric Quality Appraisal Questionnaire was used for quality assessment.

Results

The initial search yielded 1896 unique records; eight studies met inclusion criteria. Six studies were related to injury prevention in the context of recreation, two were related to sports. For recreation studies in cycling and swimming: costs per head injury averted was US$3109 to $228 197; costs per hospitalisation avoided was US$3526 to 872 794; cost per life saved/death avoided was US$3531 to $103 518 154. Sport interventions in hockey and soccer were cost saving (fewer injuries and lower costs). Global quality assessments ranged from poor to good. Important limitations included short time horizons and intermediate outcome measures.

Conclusions

Few rigorous economic evaluations related to sport and recreation injury prevention have been conducted. The range of estimates and variation in outcomes used preclude specific conclusions; however, where strategies both improve health and are cost saving, implementation should be prioritised. Future economic evaluations should incorporate time horizons sufficient to capture changes in long-term health and use utility-based outcome measures in order to capture individual preferences for changes in health states and facilitate comparison across intervention types.

Child cyclists: A study of factors affecting their safety

AIM

To study various factors that contribute to a child cyclist's risk of having, or being injured in the event of, an accident.

METHODS

All children aged 8-12 years, attending four primary schools, who had access to a bicycle were invited to participate. The study consisted of: a questionnaire; a helmet and bicycle check (by professional cycle shop staff) and a practical assessment.

RESULTS

Two hundred and ninety-three children participated in one or more parts of the study. Of the 214 helmets checked, 41% were deemed 'unsafe'. Forty-one percent of 205 bicycles checked were not considered roadworthy. Of the 127 children who usually ride their bicycle to school, 59% had either a bicycle that was not considered roadworthy or a helmet that was judged 'unsafe'. Of the 200 children, 91% knew the correct hand signals for a right and left turn. Eleven- and 12-year-olds were significantly better at performing the practical assessment than 8- to 10-year-olds (P < 0.0001).

CONCLUSIONS

Parents cannot assume that simply providing a cycle helmet and ensuring it is worn means a child will have maximum protection in the event of an accident. Calculations that base the safety benefits of cycle helmets on observation studies are likely to be underestimates. Regular checking of the roadworthiness of a child's bicycle is advised as simple things such as underinflated tyres or worn brake pads can adversely affect handling. There is no specific age at which it can be said a young child is 'safe' to ride unaccompanied on public roads.

Incidence and costs of bicycle-related traumatic brain injuries in the Netherlands

The main cause of death and serious disability in bicycle accidents is traumatic brain injury (TBI). The aim of this population-based study was to assess the incidence and costs of bicycle-related TBI across various age groups, and in comparison to all bicycle-related injuries, to identify main risk groups for the development of preventive strategies. Data from the National Injury Surveillance System and National Medical Registration were used for all patients with bicycle-related injuries and TBI who visited a Dutch emergency department (ED) between 1998 and 2012. Demographics and national, weighted estimates of injury mechanism, injury severity and costs were analysed per age group. Direct healthcare costs and indirect costs were determined using the incidence-based Dutch Burden of Injury Model. Between 1998 and 2012, the incidence of ED treatments due to bicycle-related TBI strongly increased with 54%, to 43 per 100,000 persons in 2012. However, the incidence of all bicycle-related injuries remained stable, from 444 in 1998 to 456/100,000 in 2012. Incidence of hospital admission increased in both TBI (92%) and all injuries from cycling (71%). Highest increase in incidence of both ED treatments and hospital admissions was seen in adults aged 55+. The injury rate of TBI per kilometre travelled increased (44%) except in children, but decreased (-4%) for all injuries, showing a strong decrease in children (-36%) but an increase in men aged 25+, and women aged 15+. Total costs of bicycle-related TBI were €74.5 million annually. Although bicycle-related TBI accounted for 9% of the incidence of all ED treatments due to cycling, it accounted for 18% of the total costs due to all bicycle-related injuries (€410.7 million). Children and adolescents (aged 0-24) had highest incidence of ED treatments due to bicycle-related injuries. Men in the working population (aged 15-64) had highest indirect costs following injuries from cycling, including TBI. Older cyclists (aged 55+) were identified as main risk group for TBI, as they had highest ED attendance, injury rate, injury severity, admission to hospital or intensive care unit, and costs. Incidence of ED treatments due to cycling are high and often involve TBI, imposing a high burden on individuals and society. Older cyclists aged 55+ were identified as main risk group for TBI to be targeted in preventive strategies, due to their high risk for (serious) injuries and ever-increasing share of ED visits and hospital admissions.

Traumatic brain injury: methodological approaches to estimate health and economic outcomes

The effort to standardize the methodology and adherence to recommended principles for all economic evaluations has been emphasized in medical literature. The objective of this review is to examine whether economic evaluations in traumatic brain injury (TBI) research have been compliant with existing guidelines. Medline search was performed between January 1, 1995 and August 11, 2012. All original TBI-related full economic evaluations were included in the study. Two authors independently rated each study's methodology and data presentation to determine compliance to the 10 methodological principles recommended by Blackmore et al. Descriptive analysis was used to summarize the data. Inter-rater reliability was assessed with Kappa statistics. A total of 28 studies met the inclusion criteria. Eighteen of these studies described cost-effectiveness, seven cost-benefit, and three cost-utility analyses. The results showed a rapid growth in the number of published articles on the economic impact of TBI since 2000 and an improvement in their methodological quality. However, overall compliance with recommended methodological principles of TBI-related economic evaluation has been deficient. On average, about six of the 10 criteria were followed in these publications, and only two articles met all 10 criteria. These findings call for an increased awareness of the methodological standards that should be followed by investigators both in performance of economic evaluation and in reviews of evaluation reports prior to publication. The results also suggest that all economic evaluations should be made by following the guidelines within a conceptual framework, in order to facilitate evidence-based practices in the field of TBI.

Characteristics of, and insurance payments for, injuries to cyclists in Tasmania, 1990-2010

OBJECTIVE

To describe the characteristics and costs of injuries to cyclists resulting in a 3rd party insurance claim in Tasmania.

METHODS

Data on injuries to cyclists were obtained from the Motor Accident Insurance Board (MAIB) for the period 1990-2010. Frequency and insurance costs of injuries to cyclists were compared to injuries incurred by other road users. Descriptive analyses of cycling injuries and insurance costs by year, age and sex of claimant, and type and location of injury are presented.

RESULTS

Annual costs of insurance claims by cyclists averaged AUD 3.9 million. There was a significant decrease in the frequency of claims made by all road users combined over the study period, but not for cyclists. Cycling injuries made up 2.0% of claims but accounted for 3.4% of the total costs and were among the road user groups with the highest mean costs per claim. Fractures (20.7%) were the most common cycling injury. Brain injuries led to the highest mean claim costs (AUD 1,559,032), and accounted for 66.8% of claim costs made by cyclists.

CONCLUSIONS

Mean costs per claim for cycling injuries are high compared to those made by most other road users. The costs of these injuries impose a substantial burden on insurance payers. The high costs and severity of claims by cyclists compared to other road users demonstrates the high vulnerability of cyclists, and lends support to increasing separation of cyclists from motor vehicles.

The value of statistical life in road safety: a meta-analysis

Costs of accidents make up an important part of the total external cost of traffic. A substantial proportion of accident costs is related to fatal accidents. In the evaluation of fatal accident costs the availability of an estimate of the economic value of a statistical life is pivotal. We present an overview of the empirical literature on the value of statistical life in road safety (VOSL), and use meta-analysis to determine variables that explain the variation in VOSL estimates reported in the literature. We show that the magnitude of VOSL estimates depends on the value assessment approach (particularly, stated versus revealed preference), and for contingent valuation studies also on the type of payment vehicle and elicitation format. We explain that VOSL estimates cannot simply be averaged over studies. The magnitude of VOSL is intrinsically linked to the initial level of the risk of being caught up in a fatal traffic accident and to the risk decline implied by the research set-up.

The cost effectiveness of universal antenatal screening for HIV in New Zealand

OBJECTIVE

To model the incremental costs and benefits of a universal antenatal HIV screening programme in New Zealand (NZ).

DESIGN

Cost effectiveness analysis, including only health service costs, using secondary data sources and expert opinion. Uncertainty assessed in multi-way sensitivity analyses.

SETTING

The NZ Health Care System.

SUBJECTS

Antenatal population of NZ.

INTERVENTION

Universal antenatal HIV screening programme.

MAIN OUTCOME MEASURES

Incremental cost per true-positive HIV case detected in mothers; incremental cost per HIV case avoided in babies; and incremental cost per discounted life-year gained, for mothers and babies, due to screening.

RESULTS

Using base case values the application of universal screening would cost an additional $NZ 723 607 ($US 307 917) and would lead to the identification of an additional 6.25 true-positive women. After terminations have been excluded, the screening programme would detect five HIV exposed babies. There would be 1.15 avoided cases of HIV infection in babies and a net gain of 41.97 discounted life-years, for mothers and babies combined. The cost per incremental HIV-positive woman detected was $NZ 115 859 ($US 49 301), HIV infected baby avoided $NZ 629 669 ($US 267 944) and discounted life-year gained $NZ 17 241 ($US 7336).

CONCLUSION

The discounted cost per life gained in NZ compares favourably to estimates reported in studies of similar interventions in other developed countries and other health care interventions in NZ. The decision of whether to implement universal screening in NZ would be clarified if the prevalence of antenatal HIV infection was known and policy makers identified their willingness to pay for an additional life-year gained.

New Zealand bicycle helmet law--do the costs outweigh the benefits?

OBJECTIVES

This paper examines the cost effectiveness of the compulsory bicycle helmet wearing law (HWL) introduced in New Zealand on 1 January 1994. The societal perspective of costs is used for the purchase of helmets and the value of injuries averted. This is augmented with healthcare costs averted from reduced head injuries.

METHODS

Three age groups were examined: cyclists aged 5-12 years, 13-18 years, and >/=19 years. The number of head and non-head injuries averted were obtained from epidemiological studies. Estimates of the numbers of cyclists and the costs of helmets are used to derive the total spending on new bicycle helmets. Healthcare costs were obtained from national hospitalisation database, and the value of injuries averted was obtained directly from a willingness-to-pay survey undertaken by the Land Transport Safety Authority. Cost effectiveness ratios, benefit:cost ratios, and the value of net benefits were estimated.

RESULTS

The net benefit (benefit:cost ratios) of the HWL for the 5-12, 13-18, and >/=19 year age groups was $0.3m (2.6), -$0.2m (0.8), and -$1.5m (0.7) (in NZ $, 2000 prices; NZ $1.00 = US $0.47 = UK pound 0.31 approx). These results were most sensitive to the cost and life of helmets, helmet wearing rates before the HWL, and the effectiveness of helmets in preventing head injuries.

CONCLUSIONS

The HWL was cost saving in the youngest age group but large costs from the law were imposed on adult (>/=19 years) cyclists.

Changes in head injury with the New Zealand bicycle helmet law

It was claimed that the bicycle helmet law in New Zealand reduced head injuries to adult cyclists by 28% (Povey, L.J., Frith, W.J., Graham, P.G., 1999. Cycle helmet effectiveness in New Zealand. Accident Analysis and Prevention 31, 763-770). However, the pre-law increase in adults wearing helmets (from 30% in 1990 to 43% in 1993) was accompanied by a fall of 45 head injuries per 100 limb injuries (i.e. -3.47 for every 1% increase in helmet wearing) compared with a fall of 11 when wearing increased from 43 to 93% with the law (-0.23 for every 1% increase in wearing). Unless voluntary wearing is 15 times more effective in reducing head injuries, it seems likely that the apparent effects (as described by Povey et al., 1999) were an artefact caused by failure to fit time trends in their model. Such inconsistency of effects over periods of substantial change compared with periods of little change in helmet wearing may be a useful indicator of the presence of trends. Because the large increases in wearing with helmet laws have not resulted in any obvious change over and above existing trends, helmet laws and major helmet promotion campaigns are likely to prove less beneficial and less cost effective than proven road-safety measures, such as enforcement of speed limits and drink-driving laws, education of motorists and cyclists and treatment of accident black spots and known hazards for cyclists.

Head injuries to bicyclists and the New Zealand bicycle helmet law

The purpose of this study was to examine the effect of helmet wearing and the New Zealand helmet wearing law on serious head injury for cyclists involved in on-road motor vehicle and non-motor vehicle crashes. The study population consisted of three age groups of cyclists (primary school children (ages 5-12 years), secondary school children (ages 13-18 years), and adults (19+ years)) admitted to public hospitals between 1988 and 1996. Data were disaggregated by diagnosis and analysed using negative binomial regression models. Results indicated that there was a positive effect of helmet wearing upon head injury and this effect was relatively consistent across age groups and head injury (diagnosis) types. We conclude that the helmet law has been an effective road safety intervention that has lead to a 19% (90% CI: 14, 23%) reduction in head injury to cyclists over its first 3 years.

Age gradient in the cost-effectiveness of bicycle helmets

OBJECTIVES

This study analyzed the reduction in risk of head injuries associated with use of bicycle helmets among persons ages 3 to 70 and the cost-effectiveness of helmet use based on this estimated risk reduction.

METHODS

To derive our cost-effectiveness estimates, we combined injury incidence data gathered through a detailed and comprehensive injury registration system in Norway, acute medical treatment cost information for the Norwegian health service, and information reported in the scientific literature regarding the health protective effects of helmet use. The analysis included all cases of head injuries reported through the registration system from 1990 through 1996. We performed an age-stratified analysis to determine the incidence of bicycle-related head injuries, the 5-year reduction in absolute risk of injury, the number needed to treat, and the cost-effectiveness of helmet use. To test the robustness of the findings to parameter assumptions, we performed sensitivity analysis.

RESULTS

The risk of head injury was highest among children aged 5 to 16. The greatest reduction in absolute risk of head injury, 1.0 to 1.4% over 5 years estimated helmet lifetime, occurred among children who started using a helmet between the ages of 3 and 13. Estimates indicate that it would cost approximately U.S. $2,200 in bicycle helmet expenses to prevent any one upper head injury in children ages 3-13. In contrast, it would cost U.S. $10,000-25,000 to avoid a single injury among adults.

CONCLUSIONS

Bicycle safety helmets appear to be several times more cost-effective for children than adults, primarily because of the higher risk of head injury among children. Programs aiming to increase helmet use should consider the differences in injury risk and cost-effectiveness among different age groups and target their efforts accordingly.

Evaluating the cost-effectiveness of clinical and public health measures

Cost-effectiveness analysis, an analytic tool that expresses as a ratio the cost of obtaining an additional unit of health outcome, can help decision makers achieve more health protection for the same or less cost. We characterize the state of the cost-effectiveness analysis literature by reviewing how this technique is applied to various clinical and public health interventions. We describe the results of cost-effectiveness analyses for over 40 interventions to reduce cancer, heart disease, trauma, and infectious disease. The cost-effectiveness ratios for these interventions vary enormously, from interventions that save money to those that cost more than $1 million per year of life gained. The methods used to derive the cost-effectiveness ratios also vary considerably, and we summarize this variation within each health area. Greater uniformity of analytical practice will be necessary if cost-effectiveness analysis is to become a more influential tool in debates about resource allocation.