A statewide intervention to increase safety belt use: adding to the impact of a belt use law

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.

Education, incentive, and engineering-based interventions to promote the use of seat belts

BACKGROUND

Over 1.3 million people die each year as a result of traffic collisions and hundreds of thousands of others are permanently and seriously injured. Most of these deaths occur in low- and middle-income countries, where mortality rates can be up to 10 times higher than those of some high-income countries. Seat belts are designed to accomplish two key functions - to prevent the occupant from being ejected from the vehicle by the force of impact, and to extend the time that the decelerating force is applied to a person. Seat belts also spread the area of impact both to larger and less vulnerable parts of the body. Since the 1950s, seat belts have been factory-fitted to most vehicles, and today around 90% of high-income countries have adopted seat belt legislation that makes it mandatory for some, if not all, vehicle occupants to wear seat belts. However, the simple passing of laws is not sufficient to ensure seat belt use, and, while the enforcement of seat belt laws does increase seat belt use, other interventions have been developed to encourage voluntary - and hence sustainable - behaviour change.

OBJECTIVES

To evaluate the benefits of behavioural-change interventions (educational-based, incentive-based, engineering-based, or a combination, but not enforcement-based) that promote the use of seat belts, and to determine which types of interventions are most effective.

SEARCH METHODS

On 9 August 2022, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), OvidSP Embase, OvidSP MEDLINE, 14 other databases, and clinical trials registers. We also screened reference lists and conference proceedings, searched websites of relevant organisations, and contacted road safety experts. The search was performed with no restrictions in terms of language and date of publication.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), both individually randomised and cluster-randomised, that evaluated education, engineering, incentive-based interventions (or combinations) that promoted seat belt use.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of RCTs, evaluated the risk of bias, and extracted data. We performed a narrative synthesis based on effect direction due to the heterogeneity observed between RCTs and reported the synthesis in accordance with reporting guidelines for systematic reviews without meta-analysis, as appropriate. We assessed the certainty of the evidence using the GRADE approach. We analysed data on the primary outcome, frequency of wearing a seat belt. None of the included RCTs reported the other primary outcome, crash-related injury rate or the secondary outcome, crash-related mortality rates of interest in this review.

MAIN RESULTS

We included 15 completed RCTs (12 individual, parallel-group, and three cluster) that enroled 12,081 participants, published between 1990 and 2022. Four trials were published between 2019 and 2022, and the remaining trials were published 10 or more years ago. We also identified four ongoing RCTs. Thirteen RCTs were conducted in the USA. Trials recruited participants from various sites (worksites, schools, emergency departments, a residential retirement community, and primary care settings) and different age groups (adults, late adolescents, early adolescents, and dyads). Thirteen trials investigated educational interventions, one of which used education in addition to incentives (one of the intervention arms) measured through participant self-reports (12) and observation (one), and two trials investigated engineering-based interventions measured through in-vehicle data monitor systems at various follow-up periods (six weeks to 36 months). We grouped RCTs according to types of education-based interventions: behavioural education-based, health risk appraisal (HRA), and other education-based interventions. The evidence suggests that behavioural education-based (four trials) interventions may promote seat belt use and HRA interventions (one trial) likely promote seat belt use in the short term (six weeks to nine months). Four of the six trials that investigated behavioural education-based interventions found that the intervention compared to no or another intervention may promote seat belt use. These effects were measured through participant self-report and at various time points (six-week to 12-month follow-up) (low-certainty evidence). One of the three trials investigating HRA only or with additional intervention versus no or another intervention showed observed effects likely to promote seat belt use (moderate-certainty evidence). The evidence suggests that engineering-based interventions using vehicle monitoring systems (with in-vehicle alerts and with or without notifications/feedback) may promote the use of seat belts. One trial showed that engineering interventions (in-vehicle alerts and feedback) may promote seat belt use while the other showed unclear effects in two of the three intervention groups (low-certainty evidence). Both trials had small sample sizes and high baseline seat belt use.

AUTHORS' CONCLUSIONS

The evidence suggests that behavioural education-based interventions may promote seat belt use and HRA (including incentives) with or without additional interventions likely promote seat belt use. Likewise, for engineering-based interventions using in-vehicle data monitor systems with in-vehicle alerts, with or without notifications/feedback the evidence suggests the interventions may promote the use of seat belts. Well-designed RCTs are needed to further investigate the effectiveness of education and engineering-based interventions. High-quality trials that examine the potential benefits of incentives to promote seat belt use, either alone or in combination with other interventions, as well as trials to investigate other types of interventions (such as technology, media/publicity, enforcement, insurance schemes, employer programmes, etc.) to promote the use of seat belts, are needed. Evidence from low- and middle-income economies is required to improve the generalisability of the data. In addition, research focused on determining which interventions or types of interventions are most effective in different population groups is needed.

Last resort or roll of the die? Exploring the role of metaphors in cancer clinical trials education among medically underserved populations

Improving communication about cancer clinical trials may help increase patients' understanding of medical research and their interest in participating. It is unfortunate that there is little empirical research to provide guidance on how to adapt clinical trial messages to maximize cultural sensitivity. This study examines (a) how medically underserved women conceptualize clinical trials by examining the language they use to describe them and (b) how this audience interprets metaphorical language used to explain randomization in the context of Phase III cancer clinical trials. The author conducted in-depth interviews and focus groups with 41 rural, low-income older women who either had been diagnosed with cancer or were caregivers for a person with cancer. The most commonly used lay metaphors for clinical trials had strong negative connotations and included treatment by trial and error, patients are guinea pigs, and treatment of last resort. Participants also expressed strong, unfavorable responses to conventional metaphors that equate randomization with the roll of a die or use other gambling language. Low-literacy definition approaches were unexpectedly problematic, suggesting the potential effectiveness of culturally grounded metaphors for communicating about clinical trials. Ethical implications of these findings for cancer communication are discussed.

Effectiveness of primary enforcement safety belt laws and enhanced enforcement of safety belt laws: a summary of the Guide to Community Preventive Services systematic reviews

BACKGROUND

The use of safety belts is the single most effective means of reducing fatal and nonfatal injuries in motor-vehicle crashes. This paper summarizes the systematic reviews of two interventions to increase safety belt use: primary enforcement safety belt laws and enhanced enforcement of safety belt laws. The reviews were previously published in the American Journal of Preventive Medicine.

METHODS

We conducted the systematic reviews using the methodology developed for the Guide to Community Preventive Services.

RESULTS

These reviews provide strong evidence that primary laws are more effective than secondary laws in increasing safety belt use and decreasing fatalities and that enhanced enforcement is effective in increasing safety belt use. Increases in belt use are generally highest in states with low baseline rates of belt use.

DISCUSSION

Primary safety belt laws and enhanced enforcement programs tend to result in greater increases in usage rates for target groups with lower baseline rates. Concerns regarding public opposition to these interventions may impede their implementation in some jurisdictions. However, surveys indicate that a substantial majority of the public supports implementation of both primary laws and enhanced enforcement programs.

CONCLUSION

Based on the strong evidence for effectiveness of primary safety belt laws and enhanced enforcement programs, the Task Force on Community Preventive Services recommended that all states enact primary safety belt laws and that communities implement enhanced enforcement programs.

The effect of earned and paid media strategies in high visibility enforcement campaigns

The primary objective of this paper is to describe the impact of national seat belt enforcement mobilizations in terms of changes in public awareness, perceptions, and opinions as they relate to Operation ABC (Always Buckle Up). In order to monitor changes in public awareness and perceptions, a number of national telephone surveys were conducted. Survey results indicated that the following characteristics were associated with lower self-reported seat belt use rates: (a) males; (b) 18-34 age group; (c) persons with lower income; (d) persons with lower education; (e) persons living in rural areas; (f) residents of the Northeast, Midwest, and Great Lakes; (g) residents of states with secondary enforcement laws; and (h) persons less likely to read a newspaper and more likely to listen to the radio. Telephone surveys also suggested that the following groups are more likely to fail to properly secure a child under 12: (a) persons who say they have problems securing a child in seat belt; (b) farm belt residents; (c) Hispanic and Latinos; (d) persons who indicate that they always wear a seat belt but indicate they have not in the past month; (e) persons with older vehicles; (f) lower income respondents; (g) residents of the Deep South; (h) internet non-users; and (i) urban men. These findings provide support for some basic guidelines and suggestions for conducting seat belt enforcement activities.

A meta-analysis of the effect of mediated health communication campaigns on behavior change in the United States

A meta-analysis was performed of studies of mediated health campaigns in the United States in order to examine the effects of the campaigns on behavior change. Mediated health campaigns have small measurable effects in the short-term. Campaign effect sizes varied by the type of behavior: r=.15 for seat belt use, r=.13 for oral health, r=.09 for alcohol use reduction, r=.05 for heart disease prevention, r=.05 for smoking, r=.04 for mammography and cervical cancer screening, and r=.04 for sexual behaviors. Campaigns with an enforcement component were more effective than those without. To predict campaign effect sizes for topics other than those listed above, researchers can take into account whether the behavior in a cessation campaign was addictive, and whether the campaign promoted the commencement of a new behavior, versus cessation of an old behavior, or prevention of a new undesirable behavior. Given the small campaign effect sizes, campaign planners should set modest goals for future campaigns. The results can also be useful to evaluators as a benchmark for campaign effects and to help estimate necessary sample size.

Reviews of evidence regarding interventions to increase the use of safety belts

BACKGROUND

The use of safety belts is the single most effective means of reducing fatal and nonfatal injuries in motor vehicle crashes. If all motor vehicle occupants consistently wore safety belts, an estimated 9553 deaths would have been prevented in 1999 alone.

METHODS

The Guide to Community Preventive Services's methods for systematic reviews were used to evaluate the effectiveness of three interventions to increase safety belt use. Effectiveness was assessed on the basis of changes in safety belt use and number of crash-related injuries.

RESULTS

Strong evidence was found for the effectiveness of safety belt laws in general and for the incremental effectiveness of primary safety belt laws relative to secondary laws. Strong evidence for the effectiveness of enhanced enforcement programs for safety belt laws was also found. Additional information is provided about the applicability, other effects, and barriers to implementation of these interventions.

CONCLUSIONS

These reviews form the basis of the recommendations by the Task Force on Community Preventive Services presented elsewhere in this supplement. They can help decision makers identify and implement effective interventions that fit within an overall strategy to increase safety belt use.