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Biomedical subjects

A F Williams

Publications and source records attributed to A F Williams.

At least 37 records · Page 2Linked to original sources
PubMed2001

Relationship of parent driving records to the driving records of their children.

Many studies have shown that young driver crash rates can be influenced by such factors as lifestyle characteristics and licensing systems. However, the influence of parents on their teenage children's crash and violation rates has not received much attention. The present study used data from the North Carolina driver history file to match the crash and violation records of young drivers between the ages of 18 and 21 with those of their parents. Results indicate that children's driving records in the first few years of licensure are related to the driving records of their parents. Children whose parents had three or more crashes on their record were 22% more likely to have had at least one crash compared with children whose parents had no crashes. Likewise, children whose parents had three or more violations were 38% more likely to have had a violation compared with children whose parents had none. Logistic regression models showed that these relationships held when controlling for household type and child gender.

Accidents, Traffic↗
PubMed2001

A simple method for identifying and correcting crash problems on urban arterial streets.

Urban arterials by their nature carry heavy traffic volumes and generate large numbers of motor vehicle crashes. The present study involved review of police crash reports to identify precrash events and driver actions for a sample of crashes on urban arterials and describes a method for reducing such crashes based on analyses of collision patterns and identification of locations with excessive numbers of crashes of a particular type. Police-reported crash data were obtained for three urban arterials in the Washington, DC metropolitan area. A total of 2,013 crash reports were analyzed. Seven crash types accounted for nearly 90% of these reports. On each arterial studied, several locations with excessive numbers of crashes of a particular type were identified, and corresponding engineering countermeasures were recommended. Differences between the approach employed in this study and traditional blackspot analyses are discussed.

Accidents, Traffic↗
PubMed2000

Effect of Florida's graduated licensing program on the crash rate of teenage drivers.

On 1 July 1996, Florida instituted a graduated licensing program for drivers younger than age 18. For the first 3 months, holders of learner's licenses are not allowed to drive at all between 19:00 and 06:00 h; thereafter, they may drive until 22:00 h. Learner's licenses must be held for 6 months prior to eligibility for the intermediate license. Sixteen-year-old intermediate license holders are not permitted to drive unsupervised from 23:00 to 06:00 h, 17 year-olds from 01:00 to 06:00 h. All drivers younger than 18 have strict limits on the number of traffic violations they can accumulate and, effective 1 January 1997, all drivers younger than 21 are subject to a zero tolerance law for drinking and driving. Florida crash data for 1995-1997 were obtained and compared with similar data from Alabama, a state that borders Florida but does not have graduated licensing. For 15, 16, and 17 year-olds combined, there was a 9% reduction in the fatal and injury crash involvement rate in Florida during 1997, the first full year of graduated licensing, compared with 1995. On a percentage basis, crashes declined most among 15 year-olds, followed by 16 year-olds and then 17 year-olds. Reductions were not seen among Alabama teenagers nor among 18 year-olds in Florida.

Accidents, Traffic↗
PubMed2000

Neck pain and head restraint position relative to the driver's head in rear-end collisions.

This two-year investigation was designed to estimate the incidence of driver neck pain in rear-struck vehicles involved in two-vehicle collisions and to determine the relationship between neck pain and specific vehicle, human, and environmental factors. Neck pain percentages were significantly higher for female (45%) than for male (28%) drivers. For female and male drivers, neck pain likelihood increased as head restraint height decreased below the head's center of gravity, although this effect was significant only for females. Head restraint backset, the horizontal distance measured from the back of the driver's head to the front of the head restraint, was not found to be related to neck pain for female drivers. Backset trends for male drivers could not be evaluated because few male drivers had head restraints that were high enough for backset to be relevant. Reported neck pain decreased for older drivers (females only), drivers in less severe crashes, and drivers in heavier cars (females only); all head restraint analyses were adjusted for these characteristics. Women, and most likely men, in the United States would benefit greatly from international harmonization to European head restraint standards. Until then, both women and men should be encouraged to adjust their adjustable head restraints, if possible, behind their heads' centers of gravity and to sit with the backs of their heads as close as possible to their head restraints.

Accidents, Traffic↗
PubMed2000

Measurement of carbon dioxide production in very low birth weight babies.

BACKGROUND: CO2 production is most commonly measured by using indirect calorimetry to quantify elimination of CO(2) in breath (VCO2). An alternative is to measure the rate at which CO2 appears in the body pool (RaCO2) by infusing a (13)C labelled bicarbonate tracer. VCO2 and RaCO2 generally differ but are related by c, a factor that adjusts for the incomplete recovery of infused tracer in the breath. The literature relating to human studies cites a wide range of values for c but the only neonatal study to determine c empirically estimated a mean value of 0.77. AIM: To estimate fractional recovery rate, c, in very low birthweight babies, and assess the feasibility of using the isotopic technique to measure CO2 production during mechanical ventilation. METHOD: Eleven spontaneously breathing, continuously fed, very low birthweight infants (median birth weight 1060 g, median gestational age 29 weeks) were studied. RESULTS: Mean (SD) VCO2 was 9.0 (2.0) ml/min (standard temperature and pressure dry, STPD) and mean (SD) RaCO2 was 9.6 (2.1) ml/min (STPD). The mean (SD) value of c was estimated as 0.95 (0.13). The 95% confidence intervals of the mean were 0.87-1.03. CONCLUSIONS: The results emphasise the importance of measuring c for a given study population rather than assuming a value based on adult studies. The close approximation of RaCO2 and VCO2 in this group of babies implies that the labelled bicarbonate infusion technique could be used to measure simply CO2 production during mechanical ventilation.

Breath Tests↗
PubMed2000

Child seating position and restraint use in three states.

OBJECTIVE: Because of risks from deploying airbags to children in front seats, extensive publicity has been aimed at getting them restrained and in rear seats. The objective of this study was to assess restraint use and seating positions among children in vehicles with and without airbags. METHOD: Surveys were conducted in cities in Michigan, North Carolina, and Texas 1998. Restraint use and seating position were noted for all children, as well as their estimated age, driver belt use, airbag presence, and vehicle license plate number. RESULTS: Fewer children were observed in the front seats of vehicles with passenger airbags (24%) than in vehicles without them (36%). Most of the children seated in front were ages 7-12 (44%-61%), followed by 3-6 year olds (29%-35%). Very few children ages 0-2 were seated in front (5%-12%). The overwhelming majority of children ages 0-2 were restrained. However, children ages 3-6 seated in the front were least likely to be restrained and most likely to be improperly restrained. Restraint use was higher when the driver was belted, but about 30% of 3-6 year olds were unrestrained even with a belted driver. CONCLUSIONS: Efforts should continue to educate parents about the importance of correct restraint use and rear seating for children, particularly once children move from child safety seats into adult belts. Efforts also should be made to enforce the seat belt laws that exist in every state.

Accident Prevention↗
PubMed2000

Controversies regarding definition of neonatal hypoglycemia: suggested operational thresholds.

The definition of clinically significant hypoglycemia remains one of the most confused and contentious issues in contemporary neonatology. In this article, some of the reasons for these contentions are discussed. Pragmatic recommendations for operational thresholds, ie, blood glucose levels at which clinical interventions should be considered, are offered in light of current knowledge to aid health care providers in neonatal medicine. Future areas of research to resolve some of these issues are also presented.

Adaptation, Physiological↗
PubMed2000

Area income as a predictor of preventable hospitalizations in the Harris County Hospital District, Houston.

This study assesses whether geographical area income based on census data is a good predictor of preventable (or ambulatory care-sensitive) hospitalizations in a large public hospital system in Texas, and how area income correlates with the socioeconomic status reported by patients. Documenting a correspondence between area and individual-level income, as well as meaningful variation in rates of avoidable hospitalizations across subgroups and areas with varying concentrations of low-income persons, points to the validity and utility of this approach for monitoring how well public hospital systems in Texas address the needs of those they most directly serve. Area income may not fully reflect the disproportionately lower socioeconomic status of patients seen in the public hospital system. Nonetheless, living in lower-income zip codes was associated with higher preventable hospitalization rates for the predominantly low-income population served by the public hospital system. A tenfold difference found in the adjusted rates of hospitalizations for preventable conditions compared with control (or marker) conditions among persons living in low-income areas signals the likelihood of substantial unmet needs in this population. Small-area analysis and related comparisons of rates of preventable hospitalizations in high- and low-income areas provide useful indicators for monitoring and assessing the performance of public hospital systems in Texas.

Ambulatory Care↗
PubMed2000

Variations in teenage activities with and without a driver's license.

High school students were surveyed every 6 months from their freshman through senior years concerning licensing, driving, and transportation to and from their various activities. Students in Delaware (learner's permit can be issued at age 15 years, 10 months; driver's license at age 16) were compared with students in Connecticut and New York (permit at age 16; license at age 16) and in New Jersey (license at age 17). During the junior year, most Delaware students, some New York and Connecticut students, and few New Jersey students were licensed. However, even during the junior year, students in the respective states did not differ significantly with respect to time spent at activities such as a paying job, homework, watching television, dating, parties, being with friends, talking on the phone, or participating in sports or school activities. Graduated licensing systems can delay full-privilege teenage licensure and reduce teenage crash rates. These systems also can increase the number of times parents and others must drive. However, the present study's results indicate that licensing delays of as much as 1 year have minimal effects on the nondriving activities of high school students.

Adolescent↗
PubMed1999

Evaluation of red light camera enforcement in Oxnard, California.

Red light cameras are increasingly being used to supplement police efforts to enforce against noncompliance with traffic signals--a substantial contributing factor in urban motor vehicle crashes. Camera enforcement is intended to modify driver behavior through both general deterrence and punishment of individual violators. A before/after quasi-experimental design with controls was employed to evaluate the influence of a red light camera enforcement program on red light violation rates in the city of Oxnard, CA. A total of 14 intersections (nine camera sites, three non-camera sites, and two control sites) were studied. Overall, the red light violation rate was reduced approximately 42% several months after the enforcement program began. Increases in driver compliance with red lights were not limited to the camera-equipped intersections but spilled over to nonequipped intersections as well. Results of public opinion surveys conducted approximately 6 weeks before, 6 weeks after, and 6 months after the camera enforcement program began indicated that nearly 80% of Oxnard residents support using red light cameras as a supplement to police efforts to enforce traffic signal laws.

Accidents, Traffic↗
PubMed1999

Prevalence and characteristics of red light running crashes in the United States.

About 40% of motor vehicle crashes occur at intersections. In recent years, the number of crashes at traffic signals has increased considerably. A major cause of such crashes is drivers disregarding traffic signals. Despite concerns about the frequent occurrence of red light violations and the significant crash consequences, relatively little is known about the overall prevalence and characteristics of red light running crashes. The present study examines the prevalence of red light running crashes on a national basis and identifies the characteristics of such crashes and the drivers involved. Cities with especially high rates of fatal red light running crashes are identified. Countermeasures to reduce red light running crashes based on collision patterns and characteristics of drivers involved are discussed. It was estimated that about 260000 red light running crashes occur annually in the United States, of which approximately 750 result in fatalities. Comparisons were made between red light running drivers and drivers deemed not to have run red lights in these same crashes. As a group, red light runners were more likely than other drivers to be younger than age 30, male, have prior moving violations and convictions for driving while intoxicated, have invalid driver's licenses, and have consumed alcohol prior to the crash. Comparisons also were made between characteristics of red light runners involved in daytime and nighttime crashes. Nighttime red light runners were more likely than daytime runners to be young, male, and have more deviant characteristics, 53% having high blood alcohol concentrations.

Accidents, Traffic↗
PubMed1999

'Putting the pressure on': a study of compression sleeves used in breast cancer-related lymphoedema.

Breast cancer-related lymphoedema is a chronic, progressive condition characterized by swelling in the arm and adjacent trunk, with changes to the skin and underlying tissues. The application of compression garments is an essential component in the long-term management of lymphoedema. A wide range of garments is available in the UK; however, there is limited literature to guide therapists in their appropriate selection. This paper reviews the effects of compression therapy, outlines the components of lymphoedema treatment, and discusses features of lymphoedema compression sleeves. A small study of nine women with breast cancer-related lymphoedema is reported. The study investigates the interface pressure profiles of a selection of commonly used compression sleeves as measured by the Oxford Pressure Monitor. The results showed a wide variation in the interface pressures for all sleeves. A graduated profile along the length of the arm was not always present, Two layers of garments led to markedly increased pressures at the top of the arm but the pressures along the arm did not double. The possible implications for clinical practice are discussed.

Aged↗
PubMed1999

An antipodean evaluation of problem-based learning by clinical educators.

This paper reports an evaluation by clinical nurse educators of problem-based learning (PBL) in a 3-year Australian undergraduate nursing programme. This method of learning is reliant on the students' ability to learn in a self-directed mode and is considered to bridge the 'theory-practice' gap more effectively. The purpose of this evaluation was to ascertain if this was the case. Data were collected from interviewing clinical nurse teachers at the end of the first and third years of implementing the PBL programme. Findings revealed an improvement in the students' ability to inquire and learn in a self-directed manner, and the development of a more holistic view of the patient. More conspicuous was the students' inability to perform psychomotor skills. The students also lacked knowledge in the areas of fundamental anatomy and physiology. Recommendations and actions taken by the school are discussed. This evaluation highlighted the need for continual evaluation and implementation of strategies to meet the needs of quality nurse education.

Attitude of Health Personnel↗
PubMed1999

Graduated licensing comes to the United States.

OBJECTIVE: To describe the young driver problem and the emergence of graduated licensing as a way to address it. METHODS: Literature review and commentary. RESULTS: Twenty-four states in the United States adopted versions of graduated licensing in 1996-98; initial results show positive effects. CONCLUSIONS: A major public health movement is under way that can be expected to produce significant reductions in crashes and injuries involving young drivers.

Accidents, Traffic↗