Leon S. Robertson

Prevention of motor-vehicle deaths by changing vehicle factors

Objective: To estimate the effect of changing vehicle factors to reduce mortality in a comprehensive study. Design/methods: Odds of death in the United States during 2000–2005 were analyzed, involving specific makes and models of 1999–2005 model year cars, minivans, and sport utility vehicles using logistic regression after selection of factors to be included by examination of least-squares correlations of vehicle factors to maximize independence of predictors. Based on the regression coefficients, percentages of deaths preventable by changes in selected factors were calculated. Correlations of vehicle characteristics to environmental and behavioral risk factors were also examined to assess any potential confounding. Results: Deaths in the studied vehicles would have been 42% lower had all had electronic stability control (ESC) systems. Improved crashworthiness as measured by offset frontal and side crash tests would have produced an additional 28% reduction, and static stability improvement would have reduced the deaths 11%. Although weight–power that reduces fuel economy is associated with lower risk to drivers, it increases risk of deaths to pedestrians and bicyclists but has an overall minor effect compared to the other factors. Conclusion: A large majority of motor-vehicle-related fatalities could be avoided by universal adoption of the most effective technologies.

Causal webs, preventive brooms, and housekeepers.

The concept of causal webs, which emphasises complex multiple causation of disease and injury, diverts attention and resources from preventive brooms that can sweep away the webs to reduce harm despite multiple causation. Epidemiologists who focus primarily on specification of causal paths in webs may overlook the modifiable necessary conditions for disease and injury. Necessary causes for disease and injury and necessary conditions for prevention are not always the same. Corporations and governments have the opportunity and means to reduce or eliminate many hazards to human health by changing products and processes that are hazardous. The arguments used to avoid doing so are often flawed and sometimes false. Public health scientists who focus on the behavior of corporations and government agencies that fail to employ preventive brooms of known effectiveness are more likely to contribute to harm reduction than those who focus on causal webs.

Federal Funds and State Motor Vehicle Deaths

cG4 N 1966, the Congress enacted two federal statutes aimed at reducing motor vehicle injury. The better known Motor Vehicle Safety Act provided the executive branch g I 3 with the authority to adopt and enforce standards for vehicles and equipment manufactured for sale in the z Q-0*sk.9g United States; it also provided for tire safety and the recall of vehicles with safety-related defects (1). Research on the effects of the Federal Motor Vehicle Safety Standards for new cars, promulgated in 1968 and subsequent years, indicated that deaths in the mid 1970S were some 9,oo0 per year less than expected from the age of vehicles and miles traveled (2). The second statute, the Highway Safety Act of 1966, authorized the executive branch to adopt uniform standards for state highway safety programs, icluding driver training, driver testing and examinations, vehicle registration, operation and inspection, highway design, maintenance and marking, identification and amelioration of problem locations, law enforcement, and emergency medical systems (3). The statute allowed for withholding of certain highway funds if states were not in compliance with the standards. (Actually, though threatened, withholding was never carried out.) In addition, the Act, as amended, provided grants to the states to improve programs according to state assessment of needs in specific program categories. With the exception of the controversy regarding motorcycle helmet laws, these programs have proceeded with little public attention. All but three states complied with the standard for a helmet law within a few years of the standard but, when the threat of loss of funds became real, the Congress rescinded the standard and, subsequently, many states repealed the helmet laws. The original helmet laws reduced deaths of motorcyclists about 30 percent (4), and repeal resulted in a commensurate increase (5,6). One of the state safety programs, driver education in the high schools,

Child injury control : surveillance and research questions

Injury is the leading cause of death for every year but the first of a childs life and, additionally, generates enormous costs in health care, disability, pain, and suffering. Research and programatic efforts for injury control continue to have low priority relative to their modest costs and potential to reduce health-care and other costs to society. Modest improvements in data systems would lead to more effective targeting of injury control efforts that are useful in preventing injuries. Analytic studies of changeable risk factors and effectiveness of interventions would widen the range of available interventions and their cost-effectiveness.

Reduced fatalities related to rear seat shoulder belts

Objective—To determine the effect on fatality rates in crashes of installation of shoulder belts in automobile back seats. Methods—During 1988–96, fatalities to rear outboard seat occupants of passenger cars, classified by age of occupant and vehicle curb weight were matched to data on model year in which shoulder belts became standard equipment. The same data were obtained from the same years on back seat occupants in crashes from the Crashworthiness Data System. Weighted regression was performed on death rates per occupants in crashes by belt equipment, occupant age, and vehicle weight for all occupants and occupants who claimed to be restrained. Results—The risk of death is significantly lower in vehicles equipped with shoulder belts, midsized to larger cars, and among children. Claimed child restraint use is higher in cars with shoulder belts and claimed use of shoulder belts is higher among adolescents and young adults but lower among those 35 and older. However, older occupants have lower death rates in shoulder belt equipped cars. Conclusions—Shoulder belts substantially reduce risk of death relative to lap belts at prevalent use rates in each age group. Belt effectiveness when used cannot be estimated precisely because of invalid claimed use, but the lowered rates among vehicles with shoulder belts indicates that effectiveness given prevalent use is far more efficacious than lap belts without shoulder belts.

Highway Deaths: False PR on the Effects of PR

In June, 1988, the Department of Public Safety (DPS) in South Carolina launched a media campaign, called “Highways or Dieways?”, in an attempt to reduce motor vehicle fatalities. Deaths per vehicle mile declined during the succeeding years and the DPS attributed all of the reduction to the campaign, gleaning some 62 awards in the process. This research indicates that the DPS took credit for a decline in fatalities that resulted from other factors. Fatality rates in South Carolina were actually higher during the campaign than would have been expected from the historic association of South Carolinas rates with the national rate or those of other states in the region. The campaign actually illustrates the principle that ad campaigns alone are often ineffective in changing public health.

Further reflections on the seatbelt use and effectiveness issue

In a recent letter, Cummings and Rivara1 misstate my point regarding changes in estimated belt effectiveness in the mid-1980s using the comparison of front seat occupant pairs. They cite my statement, “What is not explained by the theory [about misclassification of seatbelt use by police] is the sudden gap in police reported use by the dead and survivors that appeared in the mid-1980s”2 as faulting them for not explaining why prevalence of seatbelt use changed from 1975 to 1998. How could anyone who uses the English language with a modicum of proficiency interpret “sudden” as 23 years and “gap in police reported use by the dead and survivors” as general prevalence of belt use? Actually, a cursory look at the graph in Cummings paper that I critiqued indicates that the major reduction in risk ratios indicative of seatbelt effectiveness occurred during a short period in the mid-1980s when belt use laws were being debated and initially enacted in a few states. I noted that this debate could have changed police behavior …

Climate change, weather and road deaths

In 2015, a 7% increase in road deaths per population in the USA reversed the 35-year downward trend. Here I test the hypothesis that weather influenced the change in trend. I used linear regression to estimate the effect of temperature and precipitation on miles driven per capita in urbanizedurbanised areas of the USA during 2010. I matched date and county of death with temperature on that date and number of people exposed to that temperature to calculate the risk per persons exposed to specific temperatures. I employed logistic regression analysis of temperature, precipitation and other risk factors prevalent in 2014 to project expected deaths in 2015 among the 100 most populous counties in the USA. Comparison of actual and projected deaths provided an estimate of deaths expected without the temperature increase.

Reintegrating injury prevention.

This could be a landmark year for the journal. The future inclusion of research on injuries to persons of all ages is a welcome move toward reintegration of all aspects of the field under one banner. The interdisciplinary cooperation necessary to advance injury prevention has too often been negated by turf wars. There is an unfortunate side effect of cooperation, however. Too much credence or resources may be devoted to approaches that are ineffective or counter productive. The classic article by Haddon reprinted in this issue reminds us that injury prevention is an integral part of a public health tradition that has often been ignored or misunderstood by those who think that injury is caused largely by misbehavior. Injury and illness are physical and biological processes that have numerous points for potential intervention. Since most people are behaving in some way or another when they are injured, behavior is obviously a factor as well. One of the more persistent fights of Haddonites is with behaviorists who resist the Haddon approach to injury prevention. If there is something in the water from the Broad Street Pump that is killing people, do we launch a campaign to persuade each individual to get their water elsewhere, or do we shut down the pump? The guard rail that prevents you from going over a cliff does not care whether you left the road because of inattention, drunkenness, distraction by others in …

Health Policy, Health Behavior, and Injury Control

The United States has two policies that contribute substantially to its excessive health care costs: (1) neglect of application of cost-effective injury reduction programs and (2) required medical treatment of the injured on demand. The neglect of effective prevention programs is partly due to a non sequitur espoused since the early days of the automobile by its manufacturers (Eastman, 1984) and in recent decades by some professionals in public health, medicine, and engineering: Behavior is a major factor in injury causation; therefore, behavior must be changed to reduce injury. This false bromide is often applied as well to other major health problems, such as cancer and heart disease (e.g., American Public Health Association, 1994).