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S R Leeder

Publications and source records attributed to S R Leeder.

At least 19 recordsLinked to original sources
PubMed2006

Retinal vascular calibre and the risk of coronary heart disease-related death.

OBJECTIVE: To examine whether retinal vascular calibre independently predicts risk of coronary heart disease (CHD) -related death. METHODS: In a population-based cohort study of 3654 Australians aged > or = 49 years, retinal arteriolar and venular calibres were measured from baseline retinal photographs and the arteriole to venule ratio (AVR) was calculated. CHD-related death was confirmed from the Australian National Death Index. RESULTS: Over nine years, 78 women (4.1%) and 114 men (7.8%) had incident CHD-related deaths. In people aged 49-75 years, wider venules were associated with CHD death, with relative risk (RR) 1.8 (95% confidence interval (CI) 1.1 to 2.7) and RR 2.0 (95% CI 1.1 to 3.6) per standard deviation (SD) increase in venular calibre for men and women, respectively, after adjustment for traditional risk factors. Additionally, in women aged 49-75 years, smaller AVR and narrower arterioles were associated with CHD death (RR 1.5, 95% CI 1.1 to 2.2, and RR 1.9, 95% CI 1.0 to 3.5 per SD decrease in AVR and arteriolar calibre, respectively, after adjustment). These associations were not observed in people aged > 75 years. CONCLUSIONS: These findings suggest that microvascular disease processes may have a role in CHD development in middle-aged people, particularly in women. Retinal photography may be useful in cardiovascular risk prediction.

Aged↗
PubMed2005

Retinal microvascular signs and risk of stroke and stroke mortality.

OBJECTIVE: The purpose of this study was to assess the relation of retinal microvascular signs and incident stroke and stroke mortality in an older population. METHODS: The authors took retinal photographs on baseline participants (3,654 patients aged 49+ years) of the Blue Mountains Eye Study (1992 to 1994). They assessed the presence of retinopathy (microaneurysms, retinal hemorrhages) in participants without diabetes and retinal arteriolar signs in all participants using standardized grading protocols. Incident stroke/TIA/cerebrovascular death (combined stroke events) were identified at follow-up examinations during 1997 to 1999. RESULTS: During a 7-year period, 859 participants died, 97 (11.3%) of which died of cerebrovascular causes. Of survivors, 24 had confirmed incident stroke, and 11 had incident TIA. Combined stroke events were more frequent in participants with retinopathy (5.7%), with moderate/severe arteriovenous nicking (4.2%), or with focal arteriolar narrowing (7.2%) compared with those without (1.9%). After controlling for age, sex, systolic blood pressure, smoking, and self-rated health, retinopathy was significantly associated with combined stroke events (relative risk [RR] 1.7, 95% CI 1.0 to 2.8) in persons without diabetes. This association was stronger in those without severe hypertension (RR 2.7, CI 1.2 to 6.2) or in persons with two or more retinal microvascular signs (RR 2.7, CI 1.5 to 5.2). Generalized or focal arteriolar narrowing or arteriovenous nicking was not independently associated with combined stroke events after multivariate adjustment. CONCLUSIONS: In older Australians without diabetes, retinopathy signs predict stroke or stroke-related death independent of traditional stroke risk factors.

Age Factors↗
PubMed2004

Ethics and public health.

This paper examines the differences between clinical and public health ethics and provides several examples of contemporary public health challenges that pose ethical questions. The relations among ethics, rights and obligations are explored, because public health philosophers propose these as different ways for public health to align its activities to what we value. Resources for education in relation to the ethics of public health are identified.

Australia↗
PubMed2002

Epidemiology and predictive values of risk factors for neonatal group B streptococcal sepsis.

OBJECTIVES: To determine the incidence of and factors affecting risk factors for neonatal group B streptococcal (GBS) sepsis and their predictive values for intrapartum GBS carriage; to calculate the proportions of women eligible for intrapartum antibiotic prophylaxis (IAP) using different selection protocols. DESIGN: Cohort study. SETTING: Antenatal clinics and labour wards of a community hospital and a tertiary referral centre in western Sydney POPULATION: Women attending antenatal clinics during the study periods were invited to participate. METHODS: Approximately 500 women attending antenatal clinics were screened for GBS carriage at 26-32 weeks gestation and at delivery, using several screening methods. Clinical risk factors for neonatal sepsis were recorded during labour. MAIN OUTCOME MEASURES: Incidence of antenatal anovaginal GBS carriage and clinical risk factors during labour, their predictive values for intra-partum GBS carriage and their relationship, if any, to demographic and obstetric factors. RESULTS: Antenatal and intra-partum GBS carriage rates were similar but varied from 18% to 27%, depending on screening methods. The best positive and negative predictive values of antenatal GBS culture, for intra-partum carriage, were 69% (95% confidence interval (CI) 64-74) and 92% (95% CI 50-94) respectively Clinical risk factors occurred in similar proportions of GBS carriers and non-carriers. CONCLUSIONS: Neither early antenatal screening nor clinical risk factors are reliable predictors of intra-partum GBS carriage. Intra-partum antibiotic prophylaxis based on GBS carriage or risk factors when carrier status is unknown would involve approximately 35% of women, compared with approximately 16% if based on risk factors only Both strategies would prevent similar proportions of neonatal deaths from GBS sepsis. Compliance with a preventive protocol is the most likely determinant of its overall effectiveness.

Adult↗
PubMed2001

Ethics and evidence-based medicine.

Concerns about the ethics of evidence-based medicine (EBM) relate to possible alterations in the humane basis of clinical care. In collecting the evidence for EBM, scientists and doctors, not consumers, determine research objectives, interpret the data and implement the findings, and in doing so may disregard patients' priorities. Ethical standards, and what counts as evidence, are determined by socially or commercially powerful groups connected to powerful institutions. Such groups can generate evidence and determine "gold standard" knowledge, filtering out other, "inferior" knowledge. Applying the available evidence to predicting outcomes for individual patients involves uncertainty. Full disclosure of this uncertainty is a component of informed consent, but requires sensitivity to patients' tolerance of ambiguity. Ongoing debate about the ethics of EBM on all levels will ensure that EBM manifests intended and preferred social values and takes its rightful place in the practice of medicine and the development of health policy.

Australia↗
PubMed2001

Incidence of nursing home placement in a defined community.

OBJECTIVE: To assess cumulative incidence and non-cognitive factors predicting nursing home placement in a defined older population. DESIGN AND SETTING: Six-year follow-up of a population-based cohort living west of Sydney. PARTICIPANTS: 3654 non-institutionalised residents aged 49 years or older (82.4% of those eligible) participated in baseline examinations during 1992 to 1994. MAIN OUTCOME MEASURES: Permanent nursing home admission for long-term institutionalised aged care in New South Wales, confirmed by records of approvals by the regional Aged Care Assessment Team and subsidy payments by government. RESULTS: After excluding 384 participants who moved from the area or were lost to follow-up, 162 participants (5.0%) had been admitted to nursing homes on a permanent basis by October 1999. Of participants who died since baseline, 20% had been admitted to a nursing home before death. Of those alive, 1.6% were current nursing home residents. Six-year cumulative incidence rates for nursing home placement were 0.7%, 1.1%, 2.4%, 3.9%, 9.0%, 18.3% and 34.9% for people aged 55-59, 60-64, 65-69, 70-74, 75-79, 80-84 and 85 years or older, respectively. Non-cognitive factors at baseline predicting subsequent nursing home admission included each additional year of age (risk ratio [RR], 1.14), fair or poor compared with excellent self-rated health (RR, 2.9, 3.6), walking difficulty (RR, 3.6) and current smoking (RR, 1.9). People owning their homes had a decreased likelihood of nursing home placement (RR, 0.6). CONCLUSIONS: Incidence rates of institutional aged care doubled for each five-year interval from the age of 60 years. A range of non-cognitive factors predict nursing home placement.

Aged↗
PubMed2001

The childhood asthma prevention study (CAPS): design and research protocol of a randomized trial for the primary prevention of asthma.

The Childhood Asthma Prevention Study is a randomized controlled trial to measure whether the incidence of atopy and asthma can be reduced by house dust mite allergen reduction, a diet supplemented with omega-3 fatty acids, or a combination of both interventions. Six hundred and sixteen pregnant women whose unborn children were at high risk of developing asthma because of a family history were randomized prenatally. Study groups are as follows: Group A (placebo diet intervention, no house dust mite reduction), Group B (placebo diet intervention, active house dust mite reduction), Group C (active diet intervention, no house dust mite reduction), and Group D (active diet intervention, active house dust mite reduction). The house dust mite reduction intervention comprises use of physical and chemical methods to reduce allergen contact. The dietary intervention comprises use of a daily oil supplement from 6 months or at onset of bottle-feeding, and use of margarine and cooking oils based on sunflower or canola oils to increase omega-3 dietary intake. Data is collected quarterly until the infant is 1 year old and then half yearly until age 5 years. Questionnaires are used to collect respiratory illness history and information about diet and home environment. Dust is collected from the child's bed and bedroom and playroom floors. Blinded assessments are conducted at 18 months, 3 years, and 5 years. Skin prick tests to common allergens, blood tests, and detailed illness, medication use, and vaccination histories are collected. Primary outcomes will be the development of allergic sensitization and the presence and severity of asthma. This study is designed to measure the effectiveness of allergen reduction and dietary supplementation, both separately and in combination, for the primary prevention of atopy and asthma. The results of this study may have important implications for public health policies to reduce the incidence of childhood asthma. Control Clin Trials 2001;22:333-354

Adult↗
PubMed2001

Asthma in preschool children: prevalence and risk factors.

BACKGROUND: The prevalence of asthma in children has increased in many countries over recent years. To plan effective interventions to reverse this trend we need a better understanding of the risk factors for asthma in early life. This study was undertaken to measure the prevalence of, and risk factors for, asthma in preschool children. METHODS: Parents of children aged 3-5 years living in two cities (Lismore, n=383; Wagga Wagga, n=591) in New South Wales, Australia were surveyed by questionnaire to ascertain the presence of asthma and various proposed risk factors for asthma in their children. Recent asthma was defined as ever having been diagnosed with asthma and having cough or wheeze in the last 12 months and having used an asthma medication in the last 12 months. Atopy was measured by skin prick tests to six common allergens. RESULTS: The prevalence of recent asthma was 22% in Lismore and 18% in Wagga Wagga. Factors which increased the risk of recent asthma were: atopy (odds ratio (OR) 2.35, 95% CI 1.49 to 3.72), having a parent with a history of asthma (OR 2.05, 95% CI 1.34 to 3.16), having had a serious respiratory infection in the first 2 years of life (OR 1.93, 95% CI 1.25 to 2.99), and a high dietary intake of polyunsaturated fats (OR 2.03, 95% CI 1.15 to 3.60). Breast feeding (OR 0.41, 95% CI 0.22 to 0.74) and having three or more older siblings (OR 0.16, 95% CI 0.04 to 0.71) decreased the risk of recent asthma. CONCLUSIONS: Of the factors tested, those that have the greatest potential to be modified to reduce the risk of asthma are breast feeding and consumption of polyunsaturated fats.

Asthma↗
PubMed2000

Getting new evidence into medicine.

The rate of transfer of the knowledge gained from health and medical research into evidence-based practice is determined by many factors. Preconditions for the uptake of new evidence are the availability of good evidence, ready access to the evidence, a supportive organisational environment, and effective mechanisms for promoting knowledge uptake. Evidence-based medicine is being promoted in Australia by a body of enthusiastic clinicians, public health practitioners and consumer advocates, supported by initiatives from national, State and local healthcare services and professional bodies. The short to medium term future of evidence-based medicine in Australia is likely to be shaped by three major factors: a reduction in cost and technical barriers which limit access to computerised databases; a trend towards shared decision-making between clinicians and patients; and increased demand for information to fill the gaps in research-based evidence on specific problems.

Australia↗
PubMed2000

Dietary fat and fish intake and age-related maculopathy.

OBJECTIVE: To assess whether dietary intake of fat or fish is associated with age-related maculopathy (ARM) prevalence. DESIGN: Cross-sectional, urban population-based study. PARTICIPANTS: People (N = 3654) aged 49 years or older. MAIN OUTCOME MEASURES: Subjects with ARM were identified from masked grading of retinal photographs. A 145-itemself-administered, semiquantitative food frequency questionnaire was completed adequately by 88.8% of participants and was used to assess intakes of dietary fat and fish. RESULTS: A higher frequency of fish consumption was associated with decreased odds of late ARM (odds ratio for frequency of consumption more than once per week compared with less than once per month, 0.5). Subjects with higher energy-adjusted intakes of cholesterol were significantly more likely to have late ARM, with an increased risk for late ARM for the highest compared with the lowest quintile of intake (odds ratio, 2.7). CONCLUSION: The amount and type of dietary fat intake may be associated with ARM.

Aged↗
PubMed2000

Daycare attendance before the age of two protects against atopy in preschool age children.

Early attendance at daycare has been shown to protect against atopy, as defined by a positive skin prick test. One proposed hypothesis for this association is that early exposure to other children protects against atopy by facilitating the spread of infections among children. An alternative hypothesis is that children attending daycare centers have less atopy due to lower levels of exposure to indoor allergens. Our aim was to determine whether attendance at daycare before age 2 years protects against atopy in Australian preschool age children and to test the two alternative hypotheses, as well as a number of potential confounding factors. We conducted a cross-sectional study of children aged 3-5 years living in one humid coastal city (Lismore, n = 286) and one dry, inland city (Wagga Wagga, n = 364) in New South Wales, Australia, in 1995. Atopy was assessed by skin prick tests to six common allergens. Daycare attendance and other possible risk factors for atopy were measured by a parent-completed questionnaire. Children who attended daycare before age 2 years had a reduced risk of atopy at 3-5 years. The greatest effect was seen in children who attended a daycare center (odds ratio (OR), 0.26; 95% CI, 0.14-0.50) rather than family daycare (OR, 0.66; 95% CI, 0.41-1.04). The results of this study do not support either of the proposed hypotheses, nor can the effect be explained by any of the other potential confounders measured. Further work is needed to determine the exposure that is responsible for the protective effect of daycare attendance on atopy.

Age Factors↗
PubMed2000

Acute effects of low levels of ambient ozone on peak expiratory flow rate in a cohort of Australian children.

BACKGROUND: We enrolled a cohort of primary schoolchildren with a history of wheeze (n = 148) in an 11-month longitudinal study to examine the relationship between ambient ozone concentrations and peak expiratory flow rate. METHODS: Enrolled children recorded peak expiratory flow rates (PEFR) twice daily. We obtained air pollution, meteorological and pollen data. In all, 125 children remained in the final analysis. RESULTS: We found a significant negative association between daily mean deviation in PEFR and same-day mean daytime ozone concentration (beta-coefficient = 0.88; P = 0.04) after adjusting for co-pollutants, time trend, meteorological variables, pollen count and ALTERNARIA: count. The association was stronger in a subgroup of children with bronchial hyperreactivity and a doctor diagnosis of asthma (beta-coefficient = -2.61; P = 0.001). There was no significant association between PEFR and same-day daily daytime maximum ozone concentration. We also demonstrated a dose-response relationship with mean daytime ozone concentration. CONCLUSIONS: Moderate levels of ambient ozone have an adverse health effect on children with a history of wheezing, and this effect is larger in children with bronchial hyperreactivity and a doctor diagnosis of asthma.

Air Pollutants↗
PubMed1999

Sceptical medicine.

Explore the source record for details and available documents.

Attitude of Health Personnel↗
PubMed1999

Dietary antioxidants and age-related maculopathy: the Blue Mountains Eye Study.

OBJECTIVE: To assess associations between the stages of age-related maculopathy (ARM) and dietary intake of carotene, vitamin C, retinol, and zinc. DESIGN: Cross-sectional, population-based study. PARTICIPANTS: A total of 3654 subjects 49 years of age and older from a defined area, west of Sydney, Australia, participated. A total of 2900 participants (79.4%) completed accurate food records. INTERVENTION: Masked grading of stereoscopic macular photographs, detailed interviewer-administered questionnaire, and 145-item self-administered food frequency questionnaire. MAIN OUTCOME MEASURES: Late ARM and early ARM were diagnosed from photographic grading. RESULTS: The authors found no statistically significant associations between ARM and dietary intake of either carotene, zinc, or vitamins A or C, either from diet or supplements or from the combined intake from diet and supplements. Multivariate-adjusted odds ratios (95% confidence interval) were calculated comparing highest to lowest dietary intake quintiles. For late ARM, the odds ratios were carotene, 0.7 (range, 0.3-2.0); vitamin A, 1.2 (range, 0.5-3.3); vitamin C, 1.3 (range, 0.5-3.4); and zinc, 1.0 (range, 0.4-2.8). For early ARM, the odds ratios were carotene, 0.7 (range, 0.4-1.1); vitamin A, 1.2 (range, 0.7-2.0); vitamin C, 0.9 (range, 0.5-1.4); and zinc, 0.8 (range, 0.5-1.3). No significant trends were apparent. Adjustment for energy intake also showed no associations between these antioxidants and ARM. Further, no associations were found between increasing intake of foods high in antioxidant vitamins and decreasing prevalence of either late or early ARM. CONCLUSIONS: The authors found no associations between ARM and dietary antioxidants, either from diet alone or including supplements, or from selected foods, in the Blue Mountains Eye Study population.

Aged↗