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Biomedical subjects

G McGwin

Publications and source records attributed to G McGwin.

70 records · Page 4Linked to original sources
PubMed1999

Systemic lupus erythematosus in three ethnic groups. IV. Factors associated with self-reported functional outcome in a large cohort study. LUMINA Study Group. Lupus in Minority Populations, Nature versus Nurture.

OBJECTIVE: To identify features of systemic lupus erythematosus (SLE) associated with poor functional outcome as measured by the 36-item Medical Outcomes Study Short Form 36 Health Survey (SF-36). METHODS: Two hundred twenty-four patients with early SLE (70 Hispanic, 83 African American, and 71 white) enrolled in a longitudinal study of outcomes were evaluated at study entry. The 8 composite scales and 2 summary measures (physical and mental) of the SF-36 were the dependent variables. Independent variables--1) sociodemographic, 2) clinical features, 3) immunologic, 4) global scores, and 5) behavioral/cultural--were examined for each of the scales and summary measures and for each ethnic group. Significant variables in these analyses were then used to construct models to determine their association with each of the scales and the 2 summary measures for the entire population and the 3 ethnic groups. RESULTS: Self-reported physical and mental functioning were most consistently associated with abnormal illness-related behaviors, helplessness, fatigue, and pain at study entry. Helplessness was more strongly associated with functioning in the Hispanics than in the African American or white patients. Pain was strongly associated with physical but not mental health. The models were quite robust, accounting for 41% to 68% of the variance for the two summary measures. CONCLUSION: Patients' attitudes toward their disease, fatigue, and pain have greater impact on self-perceived functional levels, as measured by the SF-36, than do more objective measures of disease activity and damage such as the presence of specific autoantibodies and/or the occurrence of specific organ involvement. Interventions designed to improve outcome may need to include ethnic-specific as well as general strategies.

Activities of Daily Living↗
PubMed1999

Characteristics of traffic crashes among young, middle-aged, and older drivers.

An overview of the characteristics of traffic crashes among young, middle-aged and older drivers is presented. The results suggest that the youngest and the oldest drivers were more likely to be considered at-fault. With respect to crash characteristics, older drivers were less likely to have crashes involving driver fatigue, during the evening and early morning, on curved roads, during adverse weather, involving a single vehicle, and while traveling at high speeds. Conversely, older drivers were over-represented in crashes at intersections and/or involving failure to yield the right of way, unseen objects, and failure to heed stop signs or signals. Crashes occurring while turning and changing lanes were also more common among older drivers. Alcohol was less likely to be a factor in traffic crashes involving older adults. Synthesizing these results led to the conclusion that the primary problem with the young is risk-taking and lack of skill. The strength of older drivers lies in their aversion to risk, but perceptual problems and difficulty judging and responding to traffic flow often counterbalance this attribute.

Accidents, Traffic↗
PubMed1999

Aging and dark adaptation.

Older adults have serious difficulty seeing under low illumination and at night, even in the absence of ocular disease. Optical changes in the aged eye, such as pupillary miosis and increased lens density, cannot account for the severity of this problem, and little is known about its neural basis. Dark adaptation functions were measured on 94 adults ranging in age from the 20s to the 80s to assess the rate of rod-mediated sensitivity recovery after exposure to a 98% bleach. Fundus photography and a grading scale were used to characterize macular health in subjects over age 49 in order to control for macular disease. Thresholds for each subject were corrected for lens density based on individual estimates, and pupil diameter was controlled. Results indicated that during human aging there is a dramatic slowing in rod-mediated dark adaptation that can be attributed to delayed rhodopsin regeneration. During the second component of the rod-mediated phase of dark adaptation, the rate of sensitivity recovery decreased 0.02 log unit/min per decade, and the time constant of rhodopsin regeneration increased 8.4 s/decade. The amount of time to reach within 0.3 log units of baseline scotopic sensitivity increased 2.76 min/decade. These aging-related changes in rod-mediated dark adaptation may contribute to night vision problems commonly experienced by the elderly.

Adult↗
PubMed1999

Fire fatalities in older people.

OBJECTIVE: To compare the epidemiology of fire-related fatalities among older, middle-aged, and young people. DESIGN: Retrospective case series. SETTING: Alabama, 1992-1997. PARTICIPANTS: All persons fatally injured in fire-related incidents in the state of Alabama from 1992 to 1997. MEASUREMENTS: The State Fire Marshal's Office provided both demographic and autopsy information about the victim. In addition, information regarding the nature and circumstances of the fire was also obtained. RESULTS: Between 1992 and 1997, there were 674 fire-related deaths in the state of Alabama. The fire-related fatality rate was highest among older persons. The fatality rate was particularly high among older black people. The rate of fatal fires caused by heating devices was higher (15.0%) among older people compared with their young and middle-aged counterparts (6.3% and 4.5%, respectively). Fatalities among older people were least likely (26.0%) to occur if smoke detectors were present, compared with deaths among young and middle-aged persons (38.3% and 33.5%, respectively). There were fewer smoke detectors present in the fatal fires of older rural black adults and white adults (0.0% and 29.0%, respectively) compared with their urban counterparts (25.0% and 47.0%, respectively). Alcohol was not a factor in fatal fires involving older adults (29.0%) compared with those involving the young (52.0%) and middle-aged adults (73.9%). CONCLUSIONS: With the growth of the percentage of older people in the population, the problem of fire-related deaths in this age group is likely to increase. Interventions focused on this age group are necessary for the state of Alabama to meet the National Health Objectives for the year 2000.

Accidents↗
PubMed1999

Systemic lupus erythematosus in three ethnic groups: III. A comparison of characteristics early in the natural history of the LUMINA cohort. LUpus in MInority populations: NAture vs. Nurture.

AIM: To determine and contrast the socioeconomic-demographic and clinical features of patients with recent onset (< or =5 y) systemic lupus erythematosus (SLE) from three ethnic groups, Hispanic, African-American and Caucasian (H, AA, C). SUBJECTS AND METHODS: SLE cases (American College of Rheumatology criteria) (incident (n = 56), prevalent (n = 173)), were enrolled in a longitudinal study at The University of Alabama at Birmingham, The University of Texas-Houston Health Science Center and The University of Texas Medical Branch at Galveston. Socioeconomic-demographic, clinical, immunological, behavioral and psychological data were obtained using validated instruments and standard laboratory techniques, and compared. RESULTS: 70 H, 88 AA and 71 C SLE patients constitute this cohort. H and AA patients were younger and of lower socioeconomic-demographic status. They also had evidence of more frequent organ system involvement (renal, cardiovascular), more auto-antibodies, more active disease (after adjusting for discrepant socioeconomic-demographic features), lower levels of social support and more abnormal illness-related behaviors (more in H than in AA). H also were more likely to have an abrupt disease onset; C were more likely to be on antimalarials but less likely to be on corticosteroids. H, AA, and C used health care resources comparably. They had similar levels of pain and physical and mental functioning after adjusting for age, disease duration, income, education, social support, illness-related behaviors, and Systemic Lupus Activity Measure or SLAM scores. CONCLUSIONS: H and AA patients have more active SLE, at an earlier age of onset, and a less favorable socioeconomic-demographic structure (worse among the H than AA) which predispose them to a less favorable natural history.

Adolescent↗
PubMed1999

Diabetes and automobile crashes in the elderly. A population-based case-control study.

OBJECTIVE: The aim of this study was to estimate the association between diabetes and its complications and at-fault automobile crashes among older drivers. RESEARCH DESIGN AND METHODS: This was a population-based case-control study. Case subjects were drivers aged > or = 65 years who had been involved in a crash during 1996 in which they were at fault. Two control groups were selected: 1) crash-involved not-at-fault subjects and 2) non-crash-involved subjects. Telephone interviewers collected information on demographic characteristics, driving habits, diabetes sequelae and treatment, other chronic medical conditions, and visual function. RESULTS: Overall, there was no association between diabetes and at-fault crash involvement. The adjusted odds ratio (OR) for diabetes was 1.1 (CI 0.7-1.9) when case subjects were compared with either control group. However, the adjusted OR for diabetes was 2.5 (0.9-7.2) among subjects who had been involved in a crash in the 4 years preceding 1996, while it was only 0.9 (0.5-1.7) among those who had not. There was no evidence of an association between treatment modalities and at-fault crash involvement. Case subjects were, although not significantly (P = 0.25), more likely (OR 2.4) to report neuropathy compared with both control groups, and retinopathy was not associated with increased crash risk. CONCLUSIONS: This study provides no evidence that older drivers with diabetes are at increased risk for automobile crashes. There remains the possibility that those with diabetes who have more severe disease or have had multiple crashes are at increased risk.

Accidents, Traffic↗
PubMed1999

Using nonlinear regression to estimate parameters of dark adaptation.

An objective technique for estimating the kinetics of dark adaptation is presented, with which one can evaluate models with multiple parameters, evaluate several models of dark adaptation simultaneously, and rapidly analyze large data sets. Another advantage is the ability to simultaneously estimate transition times and rates of sensitivity recovery. Finally, this nonlinear regression technique does not require that the distributional properties of the data be transformed, and thus, parameter estimates are in meaningful units and reflect the actual rate of recovery of sensitivity.

Adult↗
PubMed1998

Visual processing impairment and risk of motor vehicle crash among older adults.

CONTEXT: Motor vehicle crash risk in older drivers has been associated with visual acuity loss, but only weakly so, suggesting other factors contribute. The useful field of view is a measure that reflects decline in visual sensory function, slowed visual processing speed, and impaired visual attention skills. OBJECTIVE: To identify whether measures of visual processing ability, including the useful field of view test, are associated with crash involvement by older drivers. DESIGN: Prospective cohort study with 3 years of follow-up, 1990-1993. SETTING: Ophthalmology clinic assessment of community-based sample. PATIENTS: A total of 294 drivers aged 55 to 87 years at enrollment. MAIN OUTCOME MEASURE: Motor vehicle crash occurrence. RESULTS: Older drivers with a 40% or greater impairment in the useful field of view were 2.2 times (95% confidence interval, 1.2-4.1) more likely to incur a crash during 3 years of follow-up, after adjusting for age, sex, race, chronic medical conditions, mental status, and days driven per week. This association was primarily mediated by difficulty in dividing attention under brief target durations. CONCLUSION: Reduction in the useful field of view increases crash risk in older drivers. Given the relatively high prevalence of visual processing impairment among the elderly, visual dysfunction and eye disease deserve further examination as causes of motor vehicle crashes and injury.

Accidents, Traffic↗
PubMed1998

Identifying crash involvement among older drivers: agreement between self-report and state records.

Older drivers have a high crash rate per vehicle mile of travel. Coupled with the growth of the number of older drivers on the road, this has generated interest in the identification of factors which place older drivers at increased risk. However, much of the existing research on medical and functional risk factors for crash involvement has generally been inconsistent. Methodological differences between studies have been hypothesized as being partly responsible for such inconsistencies. The source of information used to identify crash-involved drivers has been identified as one such difference. This paper reports on the agreement between self-report and state record for identifying crash involved-older drivers. We also sought to determine whether the prevalence of visual and cognitive impairment differs across crash-involved drivers identified by either or both sources. Finally, we assessed whether risk factors for crash involvement differed when crash-involved drivers were identified by either self-report or state records. Results indicated that there was a moderate level of agreement between self-reported and state-recorded crash involvement (kappa = 0.45). However, we did find significant differences between crash-involved drivers identified via state records and/or self-report with respect to demographic (age, race), driving (annual mileage, days per week driven), and vision impairment (acuity, contrast sensitivity, peripheral visual field sensitivity, useful field of view). We also found that the possibility for biased measures of association is real. Useful field of view impairment was associated with both self-reported and state-recorded crash involvement; however, the magnitude of the associations was disparate. Moreover, glaucoma was identified as a significant risk factor when considering state-recorded crashes but not self-reported crashes. While validation of these findings is required, research designed to identify risk factors for crash involvement among older drivers should carefully consider the issue of case definition, particularly if self-report is used to identify crash-involved older drivers.

Accidents, Traffic↗
PubMed1998

Vision impairment, eye disease, and injurious motor vehicle crashes in the elderly.

The objective of this case-control study was to identify visual risk factors for vehicle crashes by elderly drivers which result in injury. The sample consisted of licensed current drivers between 55 and 87 years of age who resided in Jefferson County, Alabama. Subjects were identified through Alabama Department of Public Safety (ADPS) files. Two groups of cases were identified. One group (N = 78) was defined as those drivers who had incurred at least one vehicle crash between 1985 and 1990 resulting in an injury to anyone in the involved vehicles according to the accident report. The other case group (N = 101) consisted of drivers involved in non-injurious crashes during the same time period. Controls (N = 115), also selected from ADPS files, were older drivers not involved in crashes during the same five-year period. Subjects underwent a battery of visual processing tests and a comprehensive eye examination. The main results were that restricted useful field of view and glaucoma were the only significant independent predictors of injurious crash involvement. Odds ratios (ORs) for reductions in the useful field of view of 23-40%, 41-60% and greater than 60% were 4.2 (95% confidence interval [CI], 1.5-11.8), 13.6 (95% CI, 5.8-39.7), and 17.2 (95% CI, 5.3-55.6), respectively, compared to reductions of less than 23% (p for trend < 0.001). The OR for glaucoma was 3.6 (95% CI, 1.0-12.6). Useful field of view impairment was the only variable independently associated with non-injurious crash involvement. This study implies that impaired visual processing and glaucoma may play a role in the etiology of older driver crashes which result in injury.

Accidents, Traffic↗
PubMed1998

Pediatric pedestrian injuries: a community assessment using a hospital surveillance system.

OBJECTIVE: To provide a descriptive demographic and environmental account of pedestrian injuries among children aged < or =15 years in Jefferson County, Alabama. METHODS: This was a retrospective study with a case definition for inclusion of individuals, aged < or =15 years, who suffered a pedestrian injury and sought care at The Children's Hospital of Alabama between 1989 and 1991. Demographic and injury-related information was obtained from the medical record and analyses were performed using t-test and a simple correlation. RESULTS: The majority of the cases were nonwhite, and nearly half had Medicaid or were uninsured. The most common injuries were fractures and closed head trauma. The geographic locations of injury events were not uniformly distributed: a comparison of areas wherein an injury occurred with those that were injury-free revealed a number of significant differences with regard to specific demographic, socioeconomic, and ecological factors. CONCLUSIONS: Some of the possible manageable environmental risk factors identified in this study were relatively high posted speed limits; sidewalks that were narrow, absent, or in a state of disrepair; vehicular parking on both sides of the street; and the absence of a divided highway. In this community, the most cost-effective educational intervention may best be targeted to elementary-aged schoolchildren living in areas with low-income families and that have a high density of children.

Accidents, Traffic↗
PubMedDate not supplied

Vision impairment and driving.

Driving is the primary mode of travel in many countries. It facilitates the performance of routine daily activities and is thus integral with the concept of quality of life. Vision is inarguably a fundamental component of safe driving. Drivers with certain eye conditions reduce their driving exposure and restrict their driving to the safest times, yet there is preliminary evidence that some eye conditions increase the risk of crashes. Visual acuity is only weakly related to crash involvement, whereas peripheral vision appears to play a more critical role. Color vision deficiency by itself is not a threat to safe driving. Based on the current literature, it is unclear whether other types of visual sensory impairment have a significant impact on driving safety and performance. Tests of visual attention and processing speed show great promise as methods of identifying high-risk drivers. There is a serious need for well-designed studies in key practical areas, such as the safety of low-vision drivers who use bioptic telescopes, the impact of monocular vision impairment on safety, and the effectiveness of vision rescreening policies after initial licensure. For ophthalmologists to guide patients about driving fitness, valid and reliable assessment tools must be developed and made widely available.

Accidents, Traffic↗
PubMedDate not supplied

The epidemiology of fire-related deaths in Alabama, 1992-1997.

The state of Alabama has one of the highest fire-related fatality rates in the nation. The goal of this study was to present the epidemiology of fire-related deaths in the state of Alabama. Fatality reports for all fire-related deaths in the state of Alabama from 1992 to 1997 were obtained from the State Fire Marshall's Office. Fatality rates were calculated and compared according to age, sex, and race. Descriptive statistics were generated for population and fire characteristics. Fatality rates were higher among black people, men, children, and older people. Approximately half (48.8%) of the deaths occurred between the months of November and March; July had the lowest proportion of deaths (5.0%). Residential fires accounted for the largest proportion of deaths. Fatality rates were higher for mobile home residents. Overall, smoke detectors were present in only 32.5% of the residential fires. The presence of smoke detectors was more common with deaths in urban locations (41.8%) than with deaths in rural locations (20.8%). The most frequently reported cause of fatal fires was misuse of cigarettes. More than half of the victims aged 18 years and older tested positive for alcohol. Fire prevention efforts should focus on smoke detectors, fire-safe cigarettes, and alcohol. Mobile home residents should also be targeted for fire prevention initiatives.

Accident Prevention↗