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Biomedical subjects

T Dwyer

Publications and source records attributed to T Dwyer.

At least 127 records · Page 7Linked to original sources
PubMed1987

Alcohol consumption and the risk of alcohol related cirrhosis in women.

The risks in women of cirrhosis with a likely primary alcohol aetiology were estimated for various levels of alcohol consumption in a case-control study. Data were obtained from 41 women with a first diagnosis of cirrhosis who had no evidence of non-alcohol-related cirrhosis; three matched controls were interviewed for each case. Significant increases in the risk of cirrhosis were detected at levels of consumption between 41 and 60 g daily; above this level a dose-response relation was observed. The risk of cirrhosis did not appear to be influenced by other nutritional factors or history of liver disease or use of hepatotoxic drugs. One per cent of Australian women consume more than 40 g alcohol daily, yet more than 90% of women identified with cirrhosis consumed alcohol at this level. Preventive interventions to reduce alcohol consumption in the small group of women who consume more than 40 g daily have the potential to reduce substantially the incidence of alcohol related cirrhosis.

Adult↗
PubMed1987

Chylomicrons and chylomicron remnants in coronary artery disease: a case-control study.

Epidemiologic studies of coronary artery disease have largely overlooked the role of triglyceride-rich lipoproteins circulating in the post-prandial state. We have conducted a case-control study in males which examined fasting plasma lipoproteins and lipoproteins circulating 4 h after ingestion of a test meal containing fat and cholesterol. The cases were 82 subjects with coronary artery disease confirmed by angiography, while there were two control groups: one group of 38 'hospital controls' free of significant coronary disease by angiography, and a second group of 61 'workforce controls' free of coronary disease on historical grounds. Mean plasma and LDL cholesterol levels were significantly higher and HDL cholesterol levels were significantly lower in cases than in controls. The apo-B48/apo-B100 ratio in lipoproteins Sf greater than 60 obtained 4 h post-prandially, a relative measure of chylomicron and remnant presence, was significantly higher in cases than in controls. After pooling of all data, the prevalence of coronary artery disease was found to increase progressively with the concentration of plasma cholesterol and triglycerides, total cholesterol/HDL cholesterol ratio and the apo-B48/apo-B100 ratio in Sf greater than 60, the relative risk being highest for total cholesterol/HDL cholesterol ratio. After controlling for the confounding effects of age and other lipid factors via multiple logistic regression, apo-B48/apo-B100 ratio was still a significant predictor of coronary artery disease presence (z = 1.97, P less than 0.05) in a 'dose-response' fashion. The risk of coronary artery disease in the top quartile of apo-B48/apo-B100 distribution was 2.2-fold greater than that for the bottom quartile, after adjustment for the effects of other risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Cotinine validation of self-reported smoking in commercially run community surveys.

A validation study was carried out on self-reported smoking for 1177 people in Sydney and Melbourne in 1983. Because of its long half life and the fact that smoking is its only source in body fluids, saliva cotinine was chosen as the validation measure. Cotinine levels above 250 nmol/l were used to classify people as smokers. The sensitivity of self-reported smoking was 92.6% and the specificity was 93.4%. There was some evidence that people in the process of changing their smoking status might be slow in updating their self-classification. The smoking prevalence estimate based on cotinine levels was found to be 1.7% lower than that for self-reported smoking status. The small proportion of false negatives and false positives suggests that commercially collected data banks can be valid sources of prevalence data. Correlation between cotinine level and reported cigarette consumption was not affected by sample volume, and was similar to that achieved for carbon monoxide and thiocyanate at a low 0.34. Regression analysis using self-reported cigarette consumption filter/non-filter cigarettes, and time since last cigarette as predictors, explained 13.6% of the variance in cotinine level.

Adolescent↗
PubMed1987

Targeting the smoker in an anti-smoking campaign.

Between May and September 1983, 1,661 smokers from a random sample of the populations of Sydney and Melbourne were interviewed in their homes. Of the first group, 219 were followed up 12 months later, representing a 75% response rate. Intention, measured by perceived likelihood to quit, was validated as a predictor of a later attempt to quit smoking in the cohort study. Males reported likelihood to quit more often than females. Perceived importance of smoking as a community health problem was also important in predicting attempts to change smoking status, indicating the possible importance of an agenda-setting role for the mass media in promoting change. The key finding was the interaction between health beliefs and social influence in predicting level of intention. On their own, health beliefs showed no relationship to perceived likelihood to quit, and social influence could be counterproductive. However, taken together, these two variables were strongly predictive of change. This suggests that a combination of these two messages should be used in anti-smoking campaigns.

Adolescent↗
PubMed1987

Uptake and quitting smoking trends in Australia 1974-1984.

Five cross-sectional surveys of random, cluster samples of the Australian population taken between 1974 and 1984 obtained information on the prevalence of smokers and ex-smokers. This information, however, does not provide the essential data for trend studies of smoking behavior: Estimates of the prevalence of smoking uptake and of smoking cessation are also required. The uptake rate for males ages 16-19 reached a peak in 1980. For females ages 16-19, the uptake rate reached a peak in 1983; in 1984 there was a significant drop in the percentage of female ever-smokers, which coincidentally corresponded to the introduction of large-scale, mass-media anti-smoking campaigns in Australia. A quit ratio has been defined in this study as the ratio of the proportion of ex-smokers to the proportion of those available to quit, that is, ever-smokers. This ratio enables community smoking cessation activity trends to be plotted. Quit ratios were similar for both sexes and increased at approximately 1% per year for almost all age groups studied. Overall, the percentage increase between 1974 and 1984 was greater for females than for males.

Adolescent↗
PubMed1986

Evaluation of the Sydney "Quit. For Life" anti-smoking campaign. Part 2. Changes in smoking prevalence.

Between June and November 1983, the "Quit. For Life" media campaign was conducted in Sydney to reduce the prevalence of smoking. Surveys on a cross-sectional sample of the Sydney population were conducted before and after the campaign, and similar measures were undertaken in the rest of Australia for comparison. The sample sizes for both the Sydney and control areas comprised more than 4000 subjects. In addition, a cohort of 949 residents of Sydney and Melbourne were followed for changes in the prevalence of smoking during the year of the campaign. The cross-sectional survey results for 1984 and 1983 demonstrated decreases in the prevalence of smoking of approximately 1% for both men and women in Sydney compared with the rest of Australia. In the cohort study there was a 3.4% decrease in smoking prevalence in Sydney compared with a 0.8% increase in Melbourne. The pooled estimate of the difference in smoking prevalence attributable to the campaign was 2.8% (95% confidence interval, 0.5%-5.1%).

Adolescent↗
PubMed1986

Evaluation of the Sydney "Quit. For Life" anti-smoking campaign. Part 1. Achievement of intermediate goals.

The "Quit. For Life" campaign was a media-based programme that was aimed at reducing the prevalence of smoking in Sydney. The programme committee set four intermediate goals which it felt had to be met for such a change in prevalence to occur. From households selected at random in Sydney and Melbourne, 5713 people were interviewed to assess whether the campaign attained these goals. The television commercials that were designed for the campaign, their frequency and the timing of their screening produced a higher recall of the commercial's message and the use of campaign back-up services than were specified originally in the goals. During the campaign there was a progressive increase in the number of smokers in Sydney who reported that they were likely to quit; this was significantly different from Melbourne data by the end of the campaign and thus fulfilled another campaign goal. However, shortly after the campaign ended, the proportion of smokers who intended to quit smoking was the same in the two cities. A cohort study of 949 people from the baseline study showed that, during the 12-month period of follow-up, 66% of Sydney smokers tried to stop or to reduce their smoking. In the control city, Melbourne, 60% of smokers reported making such attempts. Of the original smokers, 23% in Sydney and 9% in Melbourne quit during the follow-up period--a statistically significant difference. As well, 10% of the original ex-smokers in Sydney and 11% in Melbourne relapsed, while 4% of nonsmokers in both cities began smoking by the end of the second survey.

Adolescent↗
PubMed1983

NHMRC workshop on non-pharmacological methods of lowering blood pressure. The role of physical activity.

Cross-sectional studies have demonstrated a negative association between the reported level of leisure-time activity, measured endurance fitness, and blood pressure. There have also been a number of prospective trials; the majority indicate that an increase in fitness is followed by a fall in blood pressure. Few have included control subjects--a critical defect, since a spontaneous fall in blood pressure is customary with serial measurements in individuals. The studies which did have control subjects were examined in detail. These also generally indicated a lowering of blood pressure with increasing fitness. However, other flaws in design of these studies, such as a lack of blind assessment, prohibit confident conclusions. There is a need for further randomized, controlled, single-blind trials concerning the relationship between physical activity and blood pressure.

Adult↗
PubMed1983

An investigation of the effects of daily physical activity on the health of primary school students in South Australia.

Studies of the health effects of a daily physical activity programme have been carried out in 10-year-old school children in Adelaide, South Australia. In the first phase (1978) observations on endurance fitness, four skin folds, blood pressure and blood lipids were made before and after a randomized trial over a period of 14 weeks. Comparisons were made on over 500 children drawn from classes in seven Primary schools involved in an endurance fitness programme (1 1/4 hours per day), a skill programme and the previous physical education programme (controls). The fitness group experienced significant gains in physical work capacity (PWC) and showed significant decreases in body fat compared to the other two groups. No significant differences were observed in plasma cholesterol, triglycerides and HDL cholesterol. Subsequently in the second phase (1980) observations were made on a group of 216 10-year-old children who had already experienced two years of the physical activity programme adopted after phase one. Comparison with the observations in the 10-year-old children in 1978 made prior to the intervention revealed significantly smaller skin folds and greater PWC, with lower blood pressure reaching statistical significance for diastolic pressure in boys. The findings suggest beneficial effects on health of daily physical activity programmes within existing primary school curricula. There was no evidence of any loss of academic performance as measured by arithmetic and reading tests in spite of 45-60 minutes' loss of formal teaching time each day.

Australia↗
PubMed1982

The McCollough effect in children.

In experiment 1, children between the ages of 6 and 9 years binocularly viewed red vertical and green horizontal gratings for several minutes. This would, in adults, produce a reliable orientation-specific McCollough effect, and it was present in the children. In experiment 2, a second group of children viewed the adaptation patterns with only 1 eye, the other eye being occluded. The McCollough effect was present when the adapted eye viewed the test pattern, but, as in adults, no interocular transfer was found.

Child Development↗