Cost-effectiveness of vitamin E therapy in the treatment of patients with angiographically proven coronary narrowing (CHAOS trial). Cambridge Heart Antioxidant Study.

Epidemiologic studies have suggested that vitamin E (alpha-tocopherol) may play a preventive role in reducing the incidence of atherosclerosis. The aim of this paper was to conduct a cost-effectiveness analysis of vitamin E supplementation in patients with coronary artery disease using data from the Cambridge Heart Antioxidant Study (CHAOS). The study compared cost-effectiveness in the context of Australian and United States (US) health care utilization. The main clinical outcome used in the economic evaluation was the incidence of acute myocardial infarction (AMI) which was nonfatal. Utilization of health care resources was estimated by conducting a survey of Australian clinicians and published Australian and US cost data. Cost savings of $127 (A$181) and $578/patient randomized to vitamin E therapy compared with patients receiving placebo were found for Australian and US settings, respectively. Savings in the vitamin E group were due primarily to reduction in hospital admissions for AMI. This occurred because the vitamin E group had a 4.4% lower absolute risk of AMI than did the placebo group. Less than 10% of health care costs in the Australian evaluation was due to vitamin E ($150 [A$214/patient]). Our economic evaluation indicates that vitamin E therapy in patients with angiographically proven atherosclerosis is cost-effective in the Australian and US settings.

Repeatability of nutrient intakes estimated by a semiquantitative food frequency questionnaire in elderly subjects.

In order to evaluate the repeatability of nutrient values estimated from a semiquantitative food frequency questionnaire being used in a longitudinal study of the relationships between diet, hemostatic factors, and stroke risk in the elderly in Western Sydney, a subsample of 62 participants (24 men, 38 women) completed a repeat questionnaire approximately 1 month after baseline data were collected. The mean age was 78 years (range, 65 to 88; median, 78). Nutrient values calculated from the repeat questionnaire were not significantly different from the baseline results by paired t test. Intraclass correlation coefficients ranged from 0.63 for beta carotene to 0.82 for saturated fat. Quadratic weighted kappa values were calculated for quintile categories and these ranged from 0.50 for fiber to 0.86 for ethanol. These values are comparable to previously published results in elderly subjects and confirm that repeatability of nutrient intakes estimated using semiquantitative food frequency questionnaires is very high in the elderly. Older subjects may be more established in their dietary habits than younger subjects, so any tendency for repeatability to decrease due to impaired memory associated with advanced age is offset by a lower intraindividual variability in dietary habit.

The Western Sydney Stroke Risk in the Elderly Study. A 5-year prospective study.

Aging of the Australian population, as in other developed nations, will ensure that stroke remains one of the most important causes of death and disability. The Stroke Risk in the Elderly (SITE) study aims to measure prospectively the independent contribution of dietary, sociodemographic, blood lipid, blood pressure, and hemostatic factors to risk of stroke and other cardiovascular outcomes. The target population included all independently living men and women aged 65 years and over, residents in several retirement villages in western metropolitan Sydney, New South Wales, Australia. The study cohort consists of 225 men and 787 women, selected as a convenience sample from all eligible residents in the local government areas (LGAs) adjacent to Westmead Hospital. Participants attended a baseline session to complete dietary, life-style, medical, and sociodemographic questionnaires. Anthropomorphic variables and blood pressure were measured. Blood was taken for measurement of serum lipid, glucose, and hemostatic factors. Questionnaire results were compared with an age/sex-stratified, randomly selected sample drawn from the community (in the same LGAs), in order to quantify potential sampling and selection biases. The study cohort will be followed for a minimum of 5 years. The attendance rate of eligible residents for a baseline medical, dietary, life-style, and sociodemographic assessment was 72% for males and 69% for females. The study cohort was older, better educated, less ethnically diverse, and among women, less likely to have ever been married compared to people aged over 65 years in the comparison group. The baseline results suggest that hemostatic factors may be of importance in assessing risk of cardiovascular disease, (CVD), particularly in older men.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in serum lipids in Australian children: is diet responsible?

A total of 5211 schoolchildren aged 10-15 years participated in an Australia-wide sample survey conducted in 1985 and completed dietary and demographic assessment, and the measurement of body mass index: 1017 children aged 12 and 15 years gave blood for serum lipid analysis. Group mean differences in serum lipids and body mass index with age, sex, socioeconomic status and ethnic origin were determined. Nutritional analysis generated group mean values for daily energy intake, per cent kilo-joules from total fat, saturated fat, monosaturated fat and polyunsaturated fat, as well as the polyunsaturated:saturated fat ratio and nutrient density of fibre. In multiple regression analyses, socioeconomic and gender based differences in serum lipids could be explained by differences in diet, whereas age group differences could not. Although there were statistically significant differences in dietary fat intake on the basis of ethnic origin, these were not reflected in differences in serum lipids. For girls, dietary fat variables were more important predictors of serum lipids than body mass index. For boys, the reverse was true. These results suggest that class differences in cardiovascular risk arise from dietary differences that are present from an early age. Sex-based differences in serum lipids seem to reflect different mechanisms in girls and boys. In the former, dietary differences are of importance but for the latter, anthropomorphic (possibly exercise-linked) differences are the most important. These findings imply that cardiovascular risk preventive programmes for children need to take into account the mechanisms of social inequality and sex-based differences.

Clinical outcomes with insulin lispro compared with human regular insulin: a meta-analysis.

We performed a meta-analysis to compare insulin lispro and human regular insulin across a range of outcomes common in modern diabetes management to establish a basis for subsequent economic evaluation. We included all identifiable head-to-head randomized controlled trials, pooling dichotomous and continuous outcomes using appropriate statistical methods. Measures associated with various aspects of glycemic control (preparandial and postprandial glycemic control, glucose excursion, and glycated hemoglobin) and with hypoglycemia were evaluated. Results showed significant differences in favor of insulin lispro in the outcomes associated with postprandial glycemic control without an increase in hypoglycemia. Outcomes associated with fasting glycemic control and overall long-term glycemic control were not significantly different between insulin lispro and human regular insulin. Alternative approaches to the meta-analysis were explored but did not alter the conclusions. Thus our meta-analysis supports the existence of significant differences between insulin lispro and human regular insulin in terms of important postprandial outcome measures in diabetes. In addition, there is a practical difference in injection timing relative to meals: human regular insulin should be administered 30 to 45 minutes before eating, whereas insulin lispro can be administered 15 minutes or less before eating. These differences should be the subject of an economic evaluation to assist in determining the place of insulin lispro in diabetes management.

Effectiveness and cost effectiveness of single bolus treatment with abciximab (Reo Pro) in preventing restenosis following percutaneous transluminal coronary angioplasty in high risk patients.

OBJECTIVE: To assess the clinical effectiveness and cost effectiveness of abciximab in preventing restenosis after percutaneous transluminal coronary angioplasty (PTCA). DESIGN: Data from a previous study, the EPIC trial, were used because only this trial was able to provide event data capable of constructing a cost effectiveness analysis over six months. All other study data reviewed supported the findings of the EPIC trial. To provide indicative results on long term health outcomes, survival and event-free survival were extrapolated using US epidemiological data in a Markov modelling process. SETTING AND PATIENTS: Patients who were at high risk for ischaemic complications after PTCA, treated in the standard manner. INTERVENTIONS: Abciximab was added to the regimen of intravenous heparin and aspirin. RESULTS: The EPIC study (n = 2099) indicated an 8.1% absolute reduction in serious cardiovascular events (95% confidence interval 3.1% to 12.7%) and a 23% relative risk reduction (p = 0.001). Based on the six month trial period, the additional cost per patient free from a serious event (Australian dollars) is $13,012 and for a special risk/benefit measure of outcome, the additional cost is $14,243. Epidemiological data support extended survival and ischaemic event-free survival with clinically successful PTCA. The results of the modelled analysis indicate a cost per additional life-year gained of $5547 and a cost per additional year event-free of $4285. CONCLUSIONS: At up to six months abciximab offers improvements in clinically important outcomes. A modelling exercise explores and highlights the likelihood of significant long term health benefits. The analysis provides information for decision makers and funders to consider the value for money of abciximab.

Childhood socioeconomic status and risk of cardiovascular disease in middle aged US women: a prospective study.

OBJECTIVE: To examine prospectively the relationship of childhood socioeconomic status and risk of cardiovascular disease in middle aged women. DESIGN: A prospective cohort of women with 14 years follow up data (1976-90). SUBJECTS: A total of 117,006 registered female nurses aged 30 to 55 years in 1976 and free of diagnosed coronary heart disease, stroke, and cancer at baseline. MAIN OUTCOME MEASURES: Incident fatal coronary heart disease, non-fatal myocardial infarction, and stroke (fatal and non-fatal). RESULTS: Low socioeconomic status in childhood was associated with a modestly increased risk of incident non-fatal myocardial infarction and total cardiovascular disease in adulthood. Compared with middle aged women from white collar childhood backgrounds, the age adjusted risk of total cardiovascular disease for women from blue collar backgrounds was 1.13 (95% CI 1.02, 1.24) and that of non-fatal myocardial infarction was 1.23 (95% CI 1.06, 1.42). No significant increase in risk was observed for stroke or fatal coronary heart disease. Adjustment for differences in family and personal past medical history, medication use, exercise, alcohol intake, diet, birth weight, being breastfed in infancy, and adult socioeconomic circumstance somewhat attenuated the increased risks observed for women from blue collar childhood socioeconomic backgrounds. In multivariate analysis, women whose fathers had been manual labourers had the highest relative risk of total coronary heart disease (RR = 1.53; 95% CI 1.09, 2.16) and non-fatal myocardial infarction (RR = 1.67; 95% CI 1.11, 2.53) when compared with women whose fathers had been employed in the professions. CONCLUSION: In this group lower childhood socioeconomic status was associated with a small but significant increase in the risk of total coronary heart disease as well as non-fatal myocardial infarction. For women from the most socioeconomically disadvantaged childhood backgrounds, the association is not explained by differences in a large number of cardiovascular risk factors, by differences in adult socioeconomic status, or by differences in indices of nutrition during gestation or infancy.

Social support, marital status and living arrangement correlates of cardiovascular disease risk factors in the elderly.

Marital status and indices of social support are associated with mortality due to coronary heart disease and stroke. This association seems not entirely due to differences in recognised cardiovascular disease risk factors. The Western Sydney Stroke risk in the Elderly Study examined the relationship between marital status, living arrangements, widowhood and extent of social support, and risk factors for cardiovascular disease in men and women aged over 65 years. Unmarried men had the lowest mean HDL-C levels. Men living alone had the highest mean systolic blood pressures. The lower mean HDL-C levels and higher DBP levels seen among widows were not statistically significant after adjustment for differences in past medical history and education levels. The extent of social support was not associated with any significant differences in cardiovascular risk factor levels among men or women. We conclude that some of the increased risk of cardiovascular disease associated with socio-demographic factors among men in this age-group may be due to differences in primary cardiovascular disease risk factors. However, some of the mechanisms underlying risk of cardiovascular disease in this age-group remains obscure.

Gender-based differences in the treatment of young offenders by the police and the children's court in New South Wales, Australia.

It has been consistently reported that young males commit crimes with an average frequency five times greater than their female peers. Most data supporting this view are derived from juvenile court and police statistics. Studies using data derived from self-reported behaviour suggest that the true relative frequency may be closer to 2:1. Police and juvenile justice data for the year 1994-5 in New South Wales, Australia, were analysed in an attempt to determine whether court and police statistics might reflect a form of selection bias, where the likelihood of arrest, trial and/or sentence is a function of gender, rather than frequency and nature of offence. The results suggest that the 5:1 gender ratio reflects a strong component of gender bias in the workings of the juvenile justice system in New South Wales. If suspected of a given crime, young males are more likely to be denied bail and (if found guilty) to be given a harsher sentence than young females suspected (or found guilty) of the same crime. Overall, if found guilty of an offence, boys were four times more likely than girls to receive a custodial sentence. Therefore, boys are selectively denied access to alternate rehabilitation resources which are made available to girls who are in trouble with the law. The juvenile justice system in New South Wales requires careful examination and reform if such apparently deeply entrenched biases are to be eliminated.

Are hemostatic factors responsible for the paradoxical risk factors for coronary heart disease and stroke?

BACKGROUND: The paradoxical occurrence of a high risk of stroke in some populations at low risk for coronary heart disease has long been known. Recently, evidence has appeared linking the paradoxical risk to population-based differences in diet, serum cholesterol, and alcohol intake. However, the pathophysiological mechanism of action that would explain this paradox is unlikely to be atherosclerosis alone. SUMMARY OF COMMENT: Several recent cross-sectional and prospective population studies have shown that hemostatic factors vary between populations in a manner consistent with the paradox. Studies have also shown that certain hemostatic factors are independent predictors of risk of coronary heart disease, ischemic stroke, and, probably, hemorrhagic stroke. CONCLUSIONS: Risk factors that enhance thrombosis and reduce fibrinolysis are capable of explaining the paradoxical occurrence of the incidence of coronary heart disease and stroke in certain populations.

Differences in modifiable cardiovascular disease risk factors in Australian schoolchildren: the results of a nationwide survey.

Two thousand four hundred schoolchildren ages 9, 12, and 15 years were randomly selected to participate in the Health and Fitness Survey of Australian Schoolchildren in 1985. Data on blood lipids, aerobic fitness, blood pressure, and obesity were obtained through physical measurement. Information on socioeconomic status and ethnic origin was collected via questionnaire. Serum total cholesterol and low and high-density lipoprotein cholesterol were lowest in the oldest age group. Girls had significantly higher serum lipid levels, the difference being greatest at 15 years. However, comparison of the total cholesterol/high-density lipoprotein cholesterol ratio showed a trend in the direction of decreasing risk with increasing age for girls, with the reverse being found in boys. Fifteen-year-old girls were also the fattest and least fit of all the children, but had significantly lower systolic and diastolic blood pressures than their male peers. Children of Asian ethnic origin had significantly lower systolic and diastolic blood pressures and a significantly higher mean high-density lipoprotein cholesterol and were less likely to be overweight compared with other ethnic groups. Children from Mediterranean/Middle-East countries were significantly fatter and had a higher mean diastolic blood pressure than the other ethnic groups. These differences were detectable at age 9 years. Children from lower socioeconomic backgrounds were fatter and had a significantly lower mean high-density lipoprotein cholesterol and higher mean serum triglyceride levels. As with ethnic origin, these differences were detectable at age 9 years. The results demonstrate that age, sex, ethnic origin, and socioeconomic status can be used as variables to describe mean differences in the levels of cardiovascular risk factors in the national population of children. As some elevations in risk factors appear to be present in the youngest age group and these levels correlate with fatty streak and fibrous plaque formation in young adulthood, preventive programs should aim at intervention prior to puberty.

Cigarette smoking in Australian schoolchildren.

Six thousand, four hundred and fifty-one schoolchildren who were aged nine to 15 years completed a questionnaire about their patterns of cigarette use, as part of the nation-wide Health and Fitness Survey of Australian Schoolchildren which was conducted in 1985. The survey yielded figures for the prevalence of cigarette smoking by age, sex, socioeconomic status and ethnic origin. It also provided data on the relationship between parental smoking and smoking in children. By the age of 15 years, 32.4% of the girls and 26.0% of the boys in the study sample had smoked at least one cigarette in the seven days before they were surveyed. In some of the age-groups, the average number of cigarettes that were consumed by girl smokers equalled or exceeded that of their male counterparts. There were no significant differences in the prevalence of current cigarette smoking with differences in socioeconomic status. This finding contrasts with the pattern of use in adults. Ethnic origin was a statistically-significant predictor of smoking behaviour in children. Significantly-fewer children of Asian ethnic origin were current smokers. Parental smoking status also appeared to be an important determinant of smoking behaviour in schoolchildren. This influence was more important for girls than for boys, particularly when the mother was a smoker. The over-all findings suggest that many features of the adult pattern of cigarette use are established by the age of 15 years. The findings also supported the trend towards increased cigarette consumption by girls compared with boys that was noted by earlier researchers. These findings should encourage a serious reappraisal of the role of cigarette advertising in the promotion of smoking in young persons.

Recommended body mass index cutoff values for overweight screening programmes in Australian children and adolescents: comparisons with North American values.

OBJECTIVE: Guidelines for screening children and adolescents for overweight have recently been published by a North American Expert Committee. As Australian clinicians might uncritically adopt these recommendations, we explore the consequences of applying North American body mass index (BMI) cutoff values to an Australian population. METHODOLOGY: The Australian BMI cutoffs were calculated using the methods recommended from height and weight data for 8492 schoolchildren aged 7-15 years old. RESULTS: Smoothed Australian BMI cutoffs were similar to those derived from the first United States National Health and Nutrition Examination Survey (NHANES-I) values for whites. However, the NHANES-I cutoffs would result in systematic misclassification. Among 7 year olds, the NHANES-I 85th percentile cutoff would wrongly classify 4.6% of normal males and 9.1% of normal females as 'at risk of overweight'. At age 14 years, the NHANES-I 95th percentile cutoff would misclassify 3.5% of children as 'overweight' instead of 'at risk of overweight'. CONCLUSION: Australian screening programmes should use BMI cutoffs appropriately derived from local measurements, and these are given for Australian children.