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Biomedical subjects

A F Williams

Publications and source records attributed to A F Williams.

At least 55 records · Page 3Linked to original sources
PubMed1999

Effects of ignition interlock license restrictions on drivers with multiple alcohol offenses: a randomized trial in Maryland.

OBJECTIVES: This investigation sought to test the effectiveness of a statewide ignition interlock license restriction program for drivers with multiple alcohol-related traffic offenses. METHODS: A total of 1387 multiple offenders eligible for license reinstatement were randomly assigned to participate in an ignition interlock program (experimental group) or in the conventional postlicensing treatment program (control group). The arrest rates of these 2 groups for alcohol traffic offenses were compared for 1 year during the ignition interlock license restriction program and for 1 year after unrestricted driving privileges were returned. RESULTS: Participation in the interlock program reduced offenders' risk of committing an alcohol traffic violation within the first year by about 65%. The alcohol traffic violation rate during the first year was significantly less for participants in the interlock program (2.4%) than for those in the control group (6.7%). However, there was no statistically significant difference between these groups in the second year, after the interlock license restriction was lifted. CONCLUSIONS: Ignition interlock license restriction programs are effective at reducing recidivism among drivers with multiple alcohol offenses, at least while the restriction is in effect.

Adult↗
PubMed1998

The effect of teenage passengers on the fatal crash risk of teenage drivers.

Fatal crash-involved drivers of passenger vehicles were identified in the Fatality Analysis Reporting System for the period 1990 through 1995. Each driver was categorized as being alone in the vehicle at the time of the crash or with one or more passengers. Drivers at fault or responsible for crash occurrence were defined as all drivers involved in a single-vehicle crash, or drivers in multiple-vehicle crashes who were coded in the Fatality Analysis Reporting System as committing one or more driver errors. The results indicated that passenger presence was associated with proportionately more at-fault fatal crashes for drivers aged 24 and younger, were a neutral factor for drivers aged 25-29, and were associated with fewer at-fault involvements for drivers aged 30 and older. Relative risk of fatal crash involvement was particularly high for teenage drivers traveling, day or night, with two or more teenage passengers. Additional research is needed to determine how the added risk associated with teenage passengers riding with teenage drivers can be reduced or eliminated.

Accidents, Traffic↗
PubMed1998

Fatal crash risk for older drivers at intersections.

Risk of fatal crash involvement was calculated for older drivers relative to drivers aged 40-49 in the United States during the years 1994-1995. The results indicated that drivers ages 65-69 were 2.26 times more at risk for multiple-vehicle involvements at intersections compared with 1.29 times more at risk in all other situations. The comparable figures for drivers aged 85 and older were 10.62 for multiple-vehicle involvements at intersections compared with 3.74 for all other situations. The relative crash risk was particularly high for older drivers at uncontrolled and stop sign-controlled locations; when traveling straight or when just starting to enter the intersection; and when the specific behavioral error in the crash was failure to yield. Countermeasures will likely involve reducing or simplifying the need to detect and evaluate moving traffic coming from the left and right when at intersections. This can be accomplished by traffic signals with protected left turns, four-way stop signs, and one-way streets. Whereas such devices involve significant cost in terms of dollars and travel delay, their cost-effectiveness may have to be revisited as the United States population continues to age.

Accidents, Traffic↗
PubMed1998

The production of EAE-free lambs from infected dams using multiple ovulation and embryo transfer.

This investigation aimed to ascertain whether embryo transfer was a feasible method of breaking the disease cycle caused by Chlamydia psittaci (ovis). Ten naive ewe lambs were inoculated orally with the T76 and G188 isolates of C. psittaci (ovis) in late pregnancy. Five animals which sero-converted to the complement fixation test (CFT) were used as donors for a multiple ovulation and embryo transfer programme. Three ewes excreted chlamydiae at parturition 1 year after inoculation, with one animal exhibiting a CFT titre indicative of clinical disease. Twelve embryos collected from these three donors and transferred to seven disease-free recipients survived and were not infected, nor were their recipient dams. It therefore appears possible to infect ewe lambs during the final stages of pregnancy with the disease manifesting itself during the following breeding season. Embryos collected from infected animals do not appear to transmit the chlamydia causing enzootic abortion.

Abortion, Septic↗
PubMed1998

Effectiveness and role of driver education and training in a graduated licensing system.

Formal driver education/training programs exist in almost all jurisdictions around the world. They are generally accepted as an efficient and effective means for learning to drive, and, more importantly, for learning to drive safely, although empirical evidence for safety benefits is lacking. Recently, there has been a heightened interest in driver education/training, largely as a result of the adoption of graduated licensing in a few jurisdictions in North America and elsewhere. These jurisdictions have effectively elevated the status of driver education/training by integrating it into the licensing system. Implicitly, this suggests that driver education provides safety benefits. This article provides a contemporary review of the value of driver education/training, particularly in relation to new licensing systems such as graduated ones. The article examines the safety benefits of driver education/training and considers the merits of integrating driver education/training programs with new approaches to the licensing of young drivers.

Accidents, Traffic↗
PubMed1997

Effects of race and socioeconomic status on survival of 1,332 black, Hispanic, and white women with breast cancer.

BACKGROUND: A survival disadvantage for black women with breast cancer, which persists after controlling for stage of the disease, has been reported. This study investigates the effects of race and socioeconomic status (SES) on breast cancer survival after controlling for age, stage, histology, and type of treatment. METHODS: Kaplan-Meier and Cox proportional hazards models were used to analyze the interaction between race and SES in predicting survival in a sample of 163 black, 205 Hispanic and 964 white women with breast cancer treated at M.D. Anderson Cancer Center a (1987-1991). RESULTS: The results of univariate and multivariate analyses indicate that race was not a significant predictor of survival after adjusting for SES and other confounding factors such as demographic and disease characteristics. SES remained a significant predictor of survival after all adjustments were made. There was no evidence of differences in type of treatment by race or SES if adjustments were made for stage. CONCLUSIONS: These results suggest that institutional factors, such as access to treatment, do not explain survival differences by race or SES. Other factors associated with low SES, such as life-style and behavior, may affect survival.

Black or African American↗
PubMed1997

Drinking drivers missed at sobriety checkpoints.

OBJECTIVE: Sobriety checkpoints are an effective deterrent to alcohol-impaired driving although a substantial proportion of drinking drivers who pass through checkpoints are missed. The present study was designed to determine the extent to which police officers correctly identify individuals with blood alcohol concentrations (BACs) at or above 0.05% at checkpoints, and if there are characteristics of drivers, vehicles or checkpoints that are associated with decreased chances of detection. METHOD: To determine which drivers are likely to be missed, drivers not detained by police for additional sobriety evaluation were interviewed and voluntary breath samples were provided at 156 sobriety checkpoints in North Carolina. RESULTS: More than 50% of the drivers with BACs in excess of 0.08% and almost 90% of drivers with BACs in excess of 0.05% were not detained by officers. For drivers with BACs of 0.05% or higher, women and those 35 or younger were more likely to be missed than were men and older drivers. Drivers without passengers were more likely to be missed than those with passengers. Drivers were also more likely to be missed during weekend checkpoints. Similar results were found for drivers with BACs at or above 0.08%. CONCLUSIONS: Alerting police officers to characteristics of drinking drivers more likely to be missed may improve detection rates. In addition, passive alcohol sensors could improve the effectiveness and efficiency of sobriety checkpoints in detecting drinking drivers.

Adolescent↗
PubMed1997

Hypoglycaemia of the newborn: a review.

It is almost a century since hypoglycaemia (a reduction in the glucose concentration of circulating blood) was first described in children, and over 50 years since the condition was first recognized in infants. Nevertheless, controversy still surrounds the definition, significance, and management of neonatal hypoglycaemia. Technological developments such as bedside glucose monitoring have, paradoxically, exacerbated rather than eased the situation. This article reviews the literature on hypoglycaemia of the newborn, and covers the following: historical aspects; glucose homeostasis and metabolic adaptation at birth; the effect of low blood glucose levels on the central nervous system; the definition of hypoglycaemia; screening; prevention; treatment; research needs; and concludes with recommendations for prevention and management.

Blood Glucose↗
PubMed1997

Night driving restrictions for youthful drivers: a literature review and commentary.

The research literature on night driving curfews is reviewed. Driving at night involves high risk, particularly for young beginners. Although only about 15 percent of the total miles of 16-17-year-old drivers occur between 9 p.m. and 6 a.m., about 40 percent of their fatal crashes take place during these hours. Curfews that limit recreational driving at night without an adult have been found to substantially reduce nighttime crashes. Parents of teenagers strongly endorse curfews and favor earlier starting times than prevail in most jurisdictions with curfews. A night driving curfew is an essential component of graduated licensing, a system that phases in young beginners to full-privilege licensure, limiting initial driving to lower-risk situations.

Accidents, Traffic↗
PubMed1996

Differences in young driver crash involvement in states with varying licensure practices.

Teenage driver licensing practices and the crashes of teenagers were compared in several states with differing laws and policies regarding licensure. High school seniors in Delaware, a state with laws that allow early driving and licensure, reported that they first drove on a public road, obtained a learner's permit and obtained a driver's license at younger ages than high school seniors in other northeastern states (Connecticut, New Jersey and upstate New York). State crash data indicated that Delaware and Connecticut, which allow unrestricted licensing at age 16, showed the highest rates of 16-year-old driver involvements in nonfatal and fatal injury crashes. Pennsylvania and upstate New York, which have night driving curfews for 16 year-olds, showed lower crash rates overall and much lower crash rates during their respective curfew hours. New Jersey and Nassau and Suffolk counties, where unsupervised driving by 16 year-olds is generally not allowed, showed the lowest crash rates for 16 year-olds. Graduated licensing programs that include delayed full-privilege licensure, night driving curfews, and extended periods of supervised practice driving are a possible countermeasure for the high motor vehicle crash rates of young drivers.

Accidents, Traffic↗
PubMed1996

The use of feedback signs to increase observed daytime seat belt use in two cities in North Carolina.

Well publicized enforcement programs in North Carolina have raised seat belt use to about 80%. In an effort to find techniques to raise belt use further, signs providing feedback to drivers on belt use rates were introduced in two communities, Asheboro (population 18,000) and Greensboro (population 183,000). Feedback signs remind motorists about belt use and imply a constant and vigorous enforcement presence. The signs were prominently posted by the roadside at high volume locations; belt use information was changed weekly based on observational surveys. Observed daytime driver belt use in Asheboro increased from an average of 75% before the signs to 89% after the signs were established. At urban sites in Greensboro, driver belt use increased from 80% to 86%. Right front passenger belt use increased significantly in Asheboro but not in Greensboro. There were no changes in belt use at two interstate exit sites in Greensboro. Reasons for the differential success rates may relate to differences in initial belt use rates, community size, amount of publicity, and numbers of encounters with the signs. It is clear, however, that feedback signs can be an important supplement to belt use enforcement programs.

Accidents, Traffic↗
PubMed1995

Traffic accident involvement rates by driver age and gender.

Passenger-vehicle travel data from the 1990 Nationwide Personal Transportation Survey were combined with crash data from the 1990 Fatal Accident Reporting System and the 1990 General Estimates System to produce crash involvement rates per vehicle-mile of travel. Elevated rates were observed for drivers aged 16-19 and 75 and over. The oldest drivers had the highest fatal involvement rate, while the youngest drivers had the highest rate of involvement in all police-reported crashes. Men had a higher risk than women of experiencing a fatal crash, while women had higher rates of involvement in injury crashes and all police-reported crashes.

Accidents, Traffic↗
PubMed1995

Classifying urban crashes for countermeasure development.

Efforts to reduce urban crash rates have been hampered by a lack of information about motor vehicle crash types. The present study is based on a systematic sample of 4,526 police crash reports from four urban areas. The sample was weighted to give each area equal representation. Diagrams and narrative descriptions from each report were reviewed, and the most common crash types based on precrash driver/vehicle behavior, were identified. Fourteen crash types were defined, and five of these were found to account for 76% of all crash events and 83% of injury crashes. Although the rank order of the five types differed from city to city, they accounted for the vast majority (69%-81%) of the crashes in each. Potential countermeasures are discussed based on the predominant crash types identified in this study. For example, ran traffic control crashes, the most common types, might be reduced by changes in signal timing, providing all-red signal intervals, increasing sign visibility, and increasing sight distances.

Accidents, Traffic↗
PubMed1995

Analysis of fatal motorcycle crashes: crash typing.

There were 2074 crashes fatal to a motorcycle driver in the United States during 1992. A computer program was developed to convert Fatal Accident Reporting System (FARS) data for these crashes into standard format English language "crash reports". The computer generated reports were analyzed and crash type categories were defined. Five defined crash type categories accounted for 1785 (86%) of the 2074 crash events: Ran off-road (41%); ran traffic control (18%); oncoming or head-on (11%); left-turn oncoming (8%); and motorcyclist down (7%). Alcohol and excessive speed were common factors associated with motorcyclist crash involvement. Left turns and failure to yield were common factors associated with the involvement of other motorists. Suggested countermeasures include helmet use and enforcement of speed and impaired driving laws.

Acceleration↗