The objective was to determine if teenage driving behavior improves when a monitoring and feedback device is installed in the teen's vehicle.
Vehicles of 85 teenage drivers were fit with a device ...that detected all instances of sudden braking/acceleration, speeding, and nonuse of seat belts. Drivers were assigned randomly to one of four research groups, differing in whether or not an alert sounded in the vehicle and whether or not parents were given access to websites containing notification records. Time trends in event rates per mile traveled were compared using Poisson regression.
Seat belt use improved when violations were reported to the parent websites, and improved even more when in-vehicle alerts were activated. Consistent reductions in speeding were achieved only when teenagers received alerts about their speeding behavior, believed their speeding behavior would not be reported to parents if corrected, and when parents were being notified of such behavior by report cards.
Electronic monitoring of teenage drivers can reduce the incidence of risky behavior, especially seat belt nonuse. More complicated behavior is more difficult to change, however.
Parent participation is key to successful behavioral modification, but it is yet to be determined how best to encourage such participation.
To examine trends in alcohol consumption and alcohol-related crashes among people younger than 21 in the United States and to review evidence on the effects of minimum legal drinking age (MLDA) laws.
...Trends in alcohol-related crashes and alcohol consumption among young people were examined, and studies on the effects of lowering and raising the drinking age were reviewed.
MLDA laws underwent many changes during the 20th century in the United States. Since July 1988, the MLDA has been 21 in all 50 states and the District of Columbia. Surveys tracking alcohol consumption among high school students and young adults found that drinking declined since the late 1970 s, and most of the decline occurred by the early 1990 s. These were the years when states were establishing, or reinstating, a MLDA-21. Among fatally injured drivers ages 16–20, the percentage with positive BACs declined from 61% in 1982 to 31% in 1995, a bigger decline than for older age groups; declines occurred among the ages directly affected by raising MLDAs (ages 18–20) and among young teenagers not directly affected (ages 16–17). Almost all studies designed specifically to gauge the effects of drinking age changes show MLDAs of 21 reduce drinking, problematic drinking, drinking and driving, and alcohol-related crashes among young people. Yet many underage people still drink, many drink and drive, and alcohol remains an important risk factor in serious crashes of young drivers, especially as they progress through the teenage years. Stepped-up enforcement of MLDA and drinking and driving laws can reduce underage drinking. Recent efforts to lower MLDAs to 18 and issue licenses to drink upon completion of alcohol education have gained local and national media attention. There is no evidence that alcohol education can even partially replace the effect of MLDA-21.
The cause and effect relationship between MLDAs of 21 and reductions in highway crashes is clear. Initiatives to lower the drinking age to 18 ignore the demonstrated public health benefits of MLDAs of 21.
Lowering the drinking age to 18 will increase highway crash deaths among young people.
Objective: The initial months of licensure are especially hazardous for teenagers. Factors leading to crashes of novice 16-year-old drivers were identified. Method: Sixteen year-olds in Connecticut ...who were involved in nonfatal crashes during the first 8 months of licensure were interviewed, and police crash reports were examined. Crash types and contributing factors were identified. Results: Three-fourths of the crash-involved teenagers were at fault. Their crashes resulted primarily when they ran off the road, rear ended another vehicle, or collided with another vehicle that had the right-of-way. Three factors contributed about equally to their crashes: failing to detect another vehicle or traffic control, speeding, and losing control of the vehicle or sliding. Slippery roads also were an important factor. Most failures to detect another vehicle or traffic control involved not looking thoroughly, distraction, or inattention. Discussion: Based on the findings, potential countermeasures for reducing crashes of novice teenage drivers include adequate practice driving, in-vehicle monitoring devices, and electronic stability control. Impact on industry: More than half of the nonfatal, at-fault crashes of newly licensed 16-year-old drivers involved more than one contributing factor including speed, loss of control, and slippery roads. Efforts to reduce teenage crashes should focus on these factors.
Objectives. Older drivers are overinvolved in intersection crashes compared with younger drivers, but the reasons are not clearly understood. The purpose of the present study was to identify the ...factors that lead to older drivers' intersection crashes.
Method. Study participants were composed of two groups of older drivers-ages 70-79 (n = 78) and 80 and older (n = 76)-and a comparison group of drivers ages 35-54 (n = 73); all were at fault in intersection crashes involving nonfatal injuries. Police crash reports, telephone interviews with at-fault drivers, and photographs of intersections were used to determine the kinds of driver actions and errors that led to the intersection crashes.
Results. Drivers 80 and older had fewer rear-end crashes than drivers ages 35-54 and 70-79, and both groups of older drivers had fewer ran-off-road crashes than drivers ages 35-54. Crashes where drivers failed to yield the right-of-way increased with age and occurred mostly at stop sign-controlled intersections, generally when drivers were turning left. The reasons for failure-to-yield crashes tended to vary by age. Compared with drivers ages 35-54 and 80 and older, drivers ages 70-79 made more evaluation errors-seeing another vehicle but misjudging whether there was adequate time to proceed. In contrast, drivers 80 and older predominantly failed to see or detect the other vehicle. Drivers ages 35-54 also tended to make search errors, but theirs were due more often to distraction.
Conclusions. Factors leading to intersection crashes vary with age, even between two age groups of older drivers. Because the number of older drivers is projected to increase, it is important to identify ways to reduce the frequency and severity of their intersection crashes. Roundabouts and protected left turn lanes at signalized intersections may help to reduce failure-to-yield crashes at intersections, especially among older drivers. Crash avoidance systems may help to reduce crashes for drivers of all ages, but most systems have not been thoroughly investigated using real-world crash data.
In phylogenetic analyses with combined multigene or multiprotein data sets, accounting for differing evolutionary dynamics at different loci is essential for accurate tree prediction. Existing ...maximum likelihood (ML) and Bayesian approaches are computationally intensive. We present an alternative approach that is orders of magnitude faster. The method, Distance Rates (DistR), estimates rates based upon distances derived from gene/protein sequence data. Simulation studies indicate that this technique is accurate compared with other methods and robust to missing sequence data. The DistR method was applied to a fungal mitochondrial data set, and the rate estimates compared well to those obtained using existing ML and Bayesian approaches. Inclusion of the protein rates estimated from the DistR method into the ML calculation of trees as a branch length multiplier resulted in a significantly improved fit as measured by the Akaike Information Criterion (AIC). Furthermore, bootstrap support for the ML topology was significantly greater when protein rates were used, and some evident errors in the concatenated ML tree topology (i.e., without protein rates) were corrected.
To assess effects of the 1999 Maryland graduated driver licensing (GDL) law on both 16-year-old drivers and other road users.
Method: Calculation and comparison of crash involvement rates and ...non-fatal injury rates pre-GDL (1996–1998) and post-GDL (2001–2003) by type of road user, per population, and per licensed driver, with adjustment for trends among 30–59-year-old drivers.
Results: Post-GDL, prevalence of licensure decreased 24% among 16-year-olds, and rates of 16-year-old drivers involved in crashes significantly decreased per 16-year-old population (corrected rate ratio (RRc) 0.82; 95% CI (0.71, 0.96)). A significant decrease also was observed for non-fatal injuries per 16-year-old population among 16-year-old drivers involved in crashes (RRc 0.63; 95% CI (0.41, 0.98)). Similarly, decreases, albeit not statistically significant, were observed among their passengers and other vehicle occupants. Per 16-year-old licensed driver, a slight non-significant increase was observed in crash involvement rates; non-fatal injury rates per 16-year-old licensed driver suggest decreased risk (non-significant) among 16-year-old drivers, their passengers, and other vehicle occupants.
Summary: Maryland's GDL delayed licensure and reduced crashes and non-fatal injuries among 16-year-old drivers per population. Trends in injuries among other road users involved in crashes with 16-year-old drivers were suggestive of a benefit from GDL, although observed decreases were not significant. Per licensed driver, findings were not significant, but suggested little change in crash involvement and decreased non-fatal injuries. Because one-third fewer 16-year-olds were licensed post-GDL, these results may suggest a selection effect in licensure.
Impact on Industry: Because Maryland had nighttime restrictions for new drivers before 1999, this study suggests other components of GDL are beneficial for drivers and possibly for other road users. States with weak GDL laws should strongly consider revising them.
Objective. Prior research suggests that vehicle-based seat belt reminder systems can produce moderate increases in belt use rates. However, these findings were based on a limited set of Ford vehicles ...in one geographic location. As more vehicles with reminder systems enter the market, it is important to determine their effectiveness as well as acceptance by consumers. The present study investigated the effectiveness of Honda's belt reminder system.
Methods. Driver belt use was observed unobtrusively as drivers brought their Honda vehicles to dealerships for service. Drivers also were asked to complete a mail-in survey designed to elicit their experience with the system.
Results. Belt use was significantly higher among drivers of vehicles with belt reminders compared with drivers of vehicles without reminders (90 vs. 84 percent). Use rates in vehicles with reminders were higher among both male and female drivers and in all vehicle types observed. Drivers of the Honda vehicles with belt reminders viewed the system very favorably, and nearly 90 percent said they would want one in their next vehicle. The reminder was perceived to be most effective by part-time belt users; 81 percent of part-time users said they now use belts more often, compared with 32 percent of respondents who said they always use belts and 18 percent who use belts occasionally.
Conclusion. Belt reminders in Honda as well as Ford vehicles are increasing. Although the increase is moderate (5.6 percentage points), on a national level it could have prevented at least 736 driver deaths in 2004.
Objective: Examine real-world crash injury data to determine whether children seated with lap belts only are better protected with or without belt-positioning booster seats.
Methods: Crash injury ...rates among booster-age children were examined for three restraint categories: lap belt only, belt-positioning booster seat with lap belt, and booster seat with lap/shoulder belt. Data were drawn from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) and the Partners for Child Passenger Safety (PCPS) crash surveillance system for years 1997-2006 and 1998-2006, respectively. Main outcome measures were the percentage of crash-involved booster-age children with moderate or greater injury (maximum abbreviated injury score MAIS 2+).
Results: The estimated risk of MAIS 2+ injury among children restrained with lap belts and boosters was 0.12 percent (NASS-CDS) and 0.96 percent (PCPS), compared with 1.21 and 1.74 percent, respectively, for lap belts only. This difference was not significant due to small numbers of children in lap belts with boosters. In PCPS, children restrained by lap/shoulder belts and boosters had lower injury risk than children restrained by lap belts, with or without boosters.
Conclusions: Although data for children secured in lap belts with boosters are limited, the results suggest that boosters are not harmful. This finding is inconsistent with the current recommendation that booster seats not be used when children must be buckled with lap belts only. Data also confirm that booster seats with lap/shoulder belts remain the optimal protection for booster-age children.
Suicide is the 15th leading cause of death worldwide, with over 75% of suicides occurring in low-income and middle-income countries. Nonetheless, evidence on the association between suicide and ...poverty in low-income and middle-income countries is scarce. We did a systematic review to understand the association between suicidal ideations and behaviours and economic poverty in low-income and middle-income countries. We included studies testing the association between suicidal ideations and behaviours and economic poverty in low-income and middle-income countries using bivariate or multivariate analysis and published in English between January, 2004, and April, 2014. We identified 37 studies meeting these inclusion criteria. In 18 studies reporting the association between completed suicide and poverty, 31 associations were explored. The majority reported a positive association. Of the 20 studies reporting on the relationship between non-fatal suicidal ideations and behaviours and poverty, 36 associations were explored. Again, almost all studies reported a positive association. However, when considering each poverty dimension separately, we found substantial variations. These findings show a consistent trend at the individual level indicating that poverty, particularly in the form of worse economic status, diminished wealth, and unemployment is associated with suicidal ideations and behaviours. At the country level, there are insufficient data to draw clear conclusions. Available data show a potential benefit in addressing economic poverty within suicide prevention strategies, with particular attention to both chronic poverty and acute economic events.
The distribution of mannan binding protein (MBP) in blood donor sera was determined by enzyme-linked immunosorbent assay to establish normal concentrations. Abnormally low MBP concentrations were ...found in 16% (21 out of 135) of female partners and 14% (15 out of 108) of male partners of couples experiencing recurrent miscarriage, compared with < 5% of obstetrically normal controls (P < 0.005). This relationship was even stronger (9.5 versus 1.0%) and more significant (P < 0.002) when only subjects presumed to be homozygous for the mutant allele responsible for MBP deficiency were considered. By immunohistochemistry, MBP could be demonstrated in first trimester placenta. We suggest that low concentrations of MBP within the feto-placental unit increase susceptibility to fetal loss, possibly via an infection-induced placental cytokine imbalance.