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Biomedical subjects

R Q Ivers

Publications and source records attributed to R Q Ivers.

14 recordsLinked to original sources
PubMed2006

A cohort study of 20,822 young drivers: the DRIVE study methods and population.

BACKGROUND AND OBJECTIVE: Research on young drivers directly linking risk factors to serious injury and death outcomes is required. The DRIVE Study was established to facilitate this aim. This paper outlines the study methods and describes the population that has been recruited, in order to demonstrate that the necessary heterogeneity in risk factors has been attained. DESIGN, SETTING AND PARTICIPANTS: Drivers aged 17-24 years holding their first-stage provisional driver's licence from New South Wales, Australia, were recruited into a prospective cohort study. The participants were contacted by mail and asked to complete the study questionnaire at an online site or via a mailed questionnaire. Baseline data collection involved a questionnaire with questions to drivers about their training, risk perception, driver behavior, sensation-seeking behavior and mental health. Participants gave consent for prospective data linkage to their data on licensing, crashes and injuries, held in routinely collected databases. RESULTS: 20 822 drivers completed the baseline questionnaire, of whom 45.4% were men, 74.3% resided in capital cities and 25.7% in regional or remote areas. The recruited study population showed a wide variation in the risk factors under examination. For example, almost 40% of drivers reported drinking alcohol at hazardous levels and about 32% of participants seemed to be at a high or very high risk of psychological distress. Participants reported a mean of 67.3 h (median 60 h) of supervised driver training while holding their learner's permit. CONCLUSIONS: The DRIVE Study has a robust study design aimed at minimizing bias in the collection of outcome data. Analyses of baseline data showed substantial heterogeneity of risk factors in the study population. Subsequent prospective linkages comparing relative differences in exposures at baseline with the outcomes of interest have the potential to provide important new information needed to develop targeted interventions aimed at young drivers.

Accidents, Traffic↗
PubMed2006

Prevalence of helmet use among motorcycle riders in Vietnam.

OBJECTIVES: To investigate the rate of helmet use among motorcycle drivers in Hai Duong province of Vietnam during winter/spring 2005, and to compare the rates of helmet use by road types. METHOD: Population-based observational surveys. RESULTS: 16,560 motorcyclists were observed across 37 road sites (incorporating 5 road categories). The overall weighted average of helmet use for motorcyclists was 29.94%, with male drivers more likely to wear helmets than female drivers (odds ratio (OR) 1.64, 95% confidence interval (CI) 1.53 to 1.76). Male pillion passengers were less likely to wear helmets than female pillion passengers (OR 0.78, 95% CI 0.72 to 0.85). The number of adult drivers using helmets is larger as compared with that of young drivers (OR 8.56, 95% CI 5.93 to 12.19). The rates of helmet use were significantly higher (p<0.001) on compulsory roads and were 59.01%, 39.97%, 24.22%, 12.7% and 9.54% for national, provincial, district, commune and Hai Duong inner-city roads, respectively. CONCLUSION: Helmet legislation has increased the rate of helmet use by motorcycle drivers on compulsory roads. Elsewhere, rate of helmet use is very low, indicating that in the absence of legislation and enforcement, motorcyclists in Vietnam will not wear a helmet.

Adolescent↗
PubMed2005

"Banned from the streets I have paid to use": an analysis of Australian print media coverage of proposals for passenger and night driving restrictions for young drivers.

OBJECTIVE: To catalogue arguments that can be anticipated in public debate when passenger and night driving restrictions are being advocated. DESIGN AND SETTING: Frame analysis of all relevant coverage of these topics in Australian print media during the three month period between June and September 2004 when intensive debate on the topic occurred. MAIN OUTCOME MEASURES: Debating frames used in reports and commentary on passenger and night driving restrictions. RESULTS: There were 52 relevant articles published containing seven distinct frames supporting the restrictions and six opposing them. Overall, more instances of frames supporting the restrictions were published; these mostly focused on the potential for saving lives. Opposition to the restrictions focused largely on their inappropriateness as a road safety measure as well as on the importance of young people's autonomy and freedom. CONCLUSIONS: Advocates of passenger and night driving restrictions have a number of arguments available to advance their case; however, it is important to anticipate and address possible counter arguments. Future research should address the saliency of different arguments to the public and key decision makers in government.

Accidents, Traffic↗
PubMed2003

Vehicle year and the risk of car crash injury.

OBJECTIVE: To quantify the association between vehicle age and risk of car crash injury. DESIGN AND SETTING: Data from a population based case-control study conducted in the Auckland region in 1998/99 was used to examine the adjusted risk of car crash injury or death due to vehicle age, after controlling for a range of known confounders. Cases were all cars involved in crashes in which at least one occupant was hospitalized or killed anywhere in the Auckland region, and controls were randomly selected cars on Auckland roads. The drivers of the 571 case vehicles and 588 control vehicles completed a structured interview. MAIN OUTCOME MEASURE: Hospitalisation or death of a vehicle occupant due to car crash injury. RESULTS: Vehicles constructed before 1984 had significantly greater chance of being involved in an injury crash than those constructed after 1994 (odds ratio 2.88, 95% confidence interval (CI) 1.20 to 6.91), after adjustment for potential confounders. There was also a trend for increasing crash risk with each one year increase in vehicle age after adjustment for potential confounders (odds ratio 1.05, 95% CI 0.99 to 1.11; p = 0.09). CONCLUSION: This study quantifies the increased risk of car crash injury associated with older vehicle year and confirms this as an important public health issue.

Accidents, Traffic↗
PubMed2002

Risk factors for fractures of the wrist, shoulder and ankle: the Blue Mountains Eye Study.

Few studies have examined risk factors for fractures of the wrist, shoulder or ankle. The Blue Mountains Eye Study is a population-based longitudinal study in 3654 people aged 49 years or older resident in an area west of Sydney, Australia. Detailed eye examinations and interviews were carried out at baseline (1992-3) and after 5 years (1997-9). Information about fractures sustained during follow-up were collected by a combination of self-report and a search of hospital radiology records. After 4.7 years follow-up subjects had sustained 53 fractures of the distal forearm, 20 fractures of the proximal humerus and 33 ankle fractures. In multivariate models factors independently associated with wrist fractures in women were no vigorous exercise in the past 2 weeks (relative risk RR 0.4, 95% CI 0.2-0.9) and ever use of HRT (RR 0.4, 95% CI 0.1-1.0). Factors independently associated with ankle fractures were male sex (RR 0.3, 95% CI 0.1-0.8) and visual field loss (RR 2.8, 95% CI 1.2-6.6). These findings are in keeping with other studies, and suggest that different types of osteoporotic fracture have different, if overlapping, sets of risk factors.

Aged↗
PubMed2001

Sensitivity and specificity of tests to detect eye disease in an older population.

OBJECTIVE: To compare the ability of tests of visual function to detect the presence of eye disease. DESIGN: Cross-sectional study. PARTICIPANTS: Three thousand six hundred fifty-four of 4433 (82.4%) eligible residents of an area near Sydney aged 49 years and older had a detailed eye examination, including retinal and lens photography and subsequent grading of eye disease, tests of presenting and corrected visual acuity, contrast sensitivity, screening visual field and intraocular pressure. MAIN OUTCOME MEASURES: Receiver operator characteristic (ROC) curves were created and area under the curve compared for each vision test. Sensitivity and specificity were calculated for each test. RESULTS: No single vision test predicted the presence of eye disease with any consistency. Best-corrected visual acuity or contrast sensitivity had the highest area under the ROC curve for most eye diseases examined but had poor sensitivity and specificity. For glaucoma and diabetic retinopathy there was no difference in area under the curve for any of the tests examined, and no test had a good balance of sensitivity and specificity. Screening tests (performed with presenting correction) did not perform as well as nonscreening tests (those carried out after refraction with best correction). CONCLUSIONS: Current vision tests are not particularly good at detecting eye disease compared with the "gold standard" of a full eye examination performed by an ophthalmologist. Further work in this area should be carried out before vision screening programs can be recommended for implementation among older people.

Aged↗
PubMed2001

Diabetes and risk of fracture: The Blue Mountains Eye Study.

OBJECTIVE: To examine associations between measures of diabetes and risk of fracture in a population-based sample of older Australians. RESEARCH DESIGN AND METHODS: This was a prospective study of 3,654 subjects aged 49 years and older who were residents in the Blue Mountains, west of Sydney, Australia. At baseline, subjects were asked questions about history and treatment of diabetes, and fasting blood samples were taken. Photographs were taken of the retina and lens to grade retinopathy and cataract. Details of fractures (excluding rib and vertebral fractures) were collected by a combination of self-report and medical record searches; all fractures were radiologically confirmed. RESULTS: After 2 years of follow-up, we found that several diabetes-related factors were significantly associated (in multivariate models) with increased risk of all fractures combined, including presence of diabetic retinopathy (adjusted RR 5.4, 95% CI 2.7-10.8), diabetes duration > or = 10 years (3.3, 1.3-8.2), cortical cataract involving > or = 25% of the lens area (2.5, 1.3-4.7), and insulin treatment (5.9, 2.6-13.5). The proximal humerus was the only individual fracture site associated with diabetes. Diabetic retinopathy (10.3, 2.2-48.0), diabetes duration (for > or = 10 years duration; 11.4, 2.4-54.2), and insulin treatment (18.8, 4.0-88.7) were all associated with proximal humerus fracture. CONCLUSIONS: These data suggest a significantly increased risk of fracture associated with diabetic retinopathy, advanced cortical cataract, longer diabetes duration, and insulin treatment. However, there are some shortcomings in this study that may limit these findings.

Aged↗
PubMed2000

Visual impairment and risk of hip fracture.

As part of a case-control study, the Auckland Hip Fracture Study (1991-1994), the authors examined associations between impaired vision and risk of hip fracture. Subjects (911 cases and 910 controls aged 60 years or older) completed a questionnaire and had vision measurements taken, including measurements of visual acuity and stereopsis (depth perception). Binocular visual acuity worse than 20/60 was statistically significantly associated with increased risk of hip fracture after adjustment for age, sex, proxy response, hours of activity per week, and height (odds ratio (OR) = 1.5; 95% confidence interval (CI): 1.1, 2.0), as was having poor vision (less than 20/100) in both eyes (OR = 2.4; 95% CI: 1.0, 6.1). Having no depth perception was associated with increased risk (OR = 6.0 95% CI: 3.2, 11.1), as were categories of decreasing stereopsis (trend p = 0.0001), self-reported poor vision (OR = 1.4; 95% CI: 1.0, 1.9), not wearing glasses at the time of the fall (OR = 1.2; 95% CI: 1.0, 1.6), and increasing time since the last eye examination (trend p = 0.03). The population attributable risk of hip fracture due to poor visual acuity or stereopsis was 40%. Visual factors are important fall-related factors which influence risk of hip fracture. Risk of hip fracture may be decreased by correcting refractive error, improving stereopsis, and administering regular eye examinations.

Accidental Falls↗
PubMed2000

Visual function tests, eye disease and symptoms of visual disability: a population-based assessment.

PURPOSE: To examine associations between eye disease and tests of visual function with self-reported visual disability. METHODS: The Blue Mountains Eye Study is a cross-sectional census-based survey of eye disease in two postcode areas in the Blue Mountains, west of Sydney, Australia. Of 4433 eligible residents, 3654 (82,4%) participated. Subjects had a detailed eye examination, including tests of visual acuity, contrast sensitivity, disability glare and visual field. Lens and retinal photographs were taken and graded according to standardized protocols for presence of cataract, early and late age-related maculopathy, glaucoma, diabetic retinopathy, retinal vein occlusion and other eye diseases. An interviewer-administered questionnaire included questions about perception of visual disability. RESULTS: Scores on all tests of visual function significantly decreased with age (P < 0.0001). This decrease persisted for all tests except disability glare after excluding subjects with identifiable eye disease. The presence of one or more eye diseases was significantly associated with all (self-reported) measures of visual disability (trouble driving at night, difficulty recognizing a friend across the street, reading a newspaper or recognizing detail on televsion): mixed cataract (cortical and nuclear, or posterior subcapsular and nuclear) was associated with trouble driving at night and difficulty recognizing a friend across the street. A 10-letter (two-line) decrease in best corrected or presenting visual acuity was significantly associated with all self-reported measures of vsual dsability, as was a two-step decrease in contrast sensitvity. A five-point increase in points missing in the visual field was weakly but significantly associated with all self-reported measures of visual disability except trouble driving at night. CONCLUSIONS: Visual function declines with age. Impaired visual function was strongly, and eye disease relatively weakly associated with reports of visual disability.

Aged↗
PubMed1999

Refractive errors in an older population: the Blue Mountains Eye Study.

OBJECTIVE: To determine prevalence and associations with refractive errors in a defined older population. DESIGN: Cross-sectional study. PARTICIPANTS: A total of 3654 residents, aged 49-97, of the Blue Mountains, west of Sydney, Australia. METHODS: Comprehensive questionnaire and detailed eye examination, including refraction. MAIN OUTCOME MEASURES: Refractive error of phakic eyes, age, gender, and education. RESULTS: Prevalence rates were determined for myopia (15%), hyperopia (57%), and emmetropia (28%). Hyperopia prevalence was age-related, increasing from 36% in persons aged <60 years to 71 % of persons aged > or = 80 (P < 0.0001), whereas myopia prevalence decreased with age, from 21 % in persons aged <60 years to 10% of persons aged > or = 80 years (P < 0.0001). Younger myopic subjects in this population reported first wearing distance correction at a significantly younger age than older subjects, P < 0.0001. After adjustment for age, women were slightly more hyperopic (mean +0.75 diopters [D]) than men (mean +0.59 D, P = 0.0012. The gender-adjusted mean spherical error increased with age from +0.03 D in persons aged <60 years to +1.2 D in persons aged > or = 80 years (P < 0.0001). The gender-adjusted mean cylinder power also increased with age, from -0.6 D in persons aged <60 years to -1.2 D in persons aged > or = 80 years (P < 0.0001). The mean axis of astigmatism was "against the rule" in all age groups. Anisometropia increased with age, from a mean of 0.4 D in persons aged <60 to 0.9 D in persons aged > or = 80 years (P < 0.0001). Higher education was associated with myopia in men (P = 0.009) but not in women (P = 0.21) after adjustment for age. CONCLUSION: This report has documented the detailed refractive status of an older population, confirming previously described trends but also finding an apparent higher prevalence of myopia among younger members of this community.

Aged↗
PubMed1999

Sensory impairment and driving: the Blue Mountains Eye Study.

OBJECTIVES: This study examined the associations between vision, hearing, loss, and car accidents. METHODS: A cross-sectional survey of 3654 people aged 49 years and older in the Blue Mountains, Australia, was used. Each subject had a detailed eye examination and interview. RESULTS: Self-reported car accident rates in the past year among 2379 current drivers were 5.6% for those aged 49 to 79 years and 9.1% for those 80 years and older. A 2-line difference in visual acuity was associated with increased risk of accidents (adjusted prevalence ratio [PR] = 1.6), as was visual acuity worse than 6/18 in the right eye (PR = 2.0), overall moderate hearing loss (PR = 1.9), and hearing loss in the right ear (PR = 1.8). CONCLUSIONS: Sensory loss in drivers may be an important risk factor for car accidents.

Accidents, Traffic↗
PubMed1998

Visual impairment and falls in older adults: the Blue Mountains Eye Study.

OBJECTIVES: To examine the association between visual impairment and falls in older people. DESIGN: Cross-sectional survey of eye disease with retrospective collection of falls data. SETTING: Two postcode areas in the Blue Mountains west of Sydney, Australia. PARTICIPANTS: All people 49 years of age and older were invited to participate, 3654 (82.4%) of 4433 eligible residents took part, and 3299 answered questions about falls. MEASUREMENTS: Subjects had a detailed eye examination and answered questions about health and vision status, use of medication, and number of falls in the previous 12 months. RESULTS: Tests of visual function that had a statistically significant association with two or more falls after adjustment for confounders were visual acuity (prevalence ratio (PR) 1.9 for visual acuity worse than 20/30), contrast sensitivity (PR 1.2 for a 1-unit decrease at 6 cycles per degree), and suprathreshold visual field screening (PR 1.5 for 5 or more points missing). However, only visual acuity and contrast sensitivity were significantly associated with two or more falls per 1 standard deviation decrease. The presence of posterior subcapsular cataract (PR 2.1) and use of nonmiotic glaucoma medication (PR 2.0) had a statistically significant association with two or more falls; presence of age-related macular degeneration, diabetic retinopathy, and cortical or nuclear cataract did not. CONCLUSION: Visual impairment is strongly associated with two or more falls in older adults. In addition to poor visual acuity, visual factors such as reduced visual field, impaired contrast sensitivity, and the presence of cataract may explain this association.

Accidental Falls↗
PubMed1997

Lack of association between localized cataract and visual field loss: the Blue Mountains Eye Study.

PURPOSE: To examine whether localized cataract is related to localized field defects on suprathreshold visual field testing. METHODS: Suprathreshold screening visual fields (Humphrey 76-point test) and lens photographs, graded using the Wisconsin System, were performed on participants attending the Blue Mountains Eye Study, which examined 3654 subjects residing in an area west of Sydney, NSW, Australia. The results for 2276 subjects were analysed in the present study. RESULTS: There were no significant relationships between total points missing in the visual field and the degree of cortical, posterior subcapsular (PSC) or nuclear cataract after adjusting for confounders (test for trend P = 0.9, 0.7 and 0.9, respectively). Adjusted prevalence ratios and 95% confidence limits for the association between 10 or more points missing and the presence of cataract were 0.94 (0.77-1.25) for cortical, 1.26 (0.82-1.93) for PSC and 1.06 (0.86-1.30) for nuclear cataract. Similarly, there was no relationship between the presence of cortical or PSC cataract and sectoral visual field loss in any quadrant or hemifield. CONCLUSIONS: Neither cortical, nuclear nor PSC cataracts increase the total points missing on the 76-point suprathreshold field test. Similarly, neither cortical nor PSC cataracts cause sectoral visual field loss on this screening field test. In the presence of cataract, sectoral visual field loss on non-thresholding visual field screeners must be attributed to other causes, such as glaucoma. The present study provides a clinical alert that localized field loss is unlikely to be related to cataract.

Aged↗