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Biomedical subjects

B K Armstrong

Publications and source records attributed to B K Armstrong.

At least 91 records · Page 5Linked to original sources
PubMed1989

Public health, epidemiology and health services.

Public health and the wider aspects of health administration are connected by their common dependence on the methods of epidemiology. Epidemiology is defined herein as the discipline of occurrence research in medicine. As such, it represents a body of methods rather than knowledge, and is as much applicable to study of the occurrence of phenomena relevant to health services as to phenomena relevant to disease aetiology and prevention. In consequence, much of the information base necessary to the development of health policy is obtained by the use of epidemiological methods. Health services planning and program development depend on an understanding of the relationship between services and the population that they serve, an understanding which is provided by the application of epidemiological concepts. The ongoing delivery of programs in a manner which optimises the use of health resources depends on the ability to respond to changes in the health services environment. Recognition of the changes demanding a response depends on continuing surveillance of the "environment" by use of epidemiological techniques. Finally, the evaluation of health programs against their objectives depends to a substantial degree on the use of epidemiological methods. The discipline of epidemiology arose in public health, but it now belongs to the whole of the health system.

Adult↗
PubMed1988

Identifying people at high risk of cutaneous malignant melanoma: results from a case-control study in Western Australia.

To assess whether screening people at high risk of malignant melanoma would be effective in reducing the mortality from the disease data from 400 case-control pairs in a study of cutaneous malignant melanoma conducted in Western Australia during 1980-1 were used to predict the risk of melanoma in the remaining 111 pairs. All variables previously shown to be associated with a decrease or increase in the incidence of melanoma were considered for inclusion in a single conditional logistic regression model of the incidence of melanoma in the randomly chosen subset of 400 case-control pairs. Five of these variables--number of raised naevi on the arms, arrival in Australia before 10 years of age, history of non-melanocytic skin cancer, time spent outdoors in summer from the age of 10 to 24, and family history of melanoma--provided good discrimination between patients and controls in this sample and the 111 other case-control pairs. Among the 222 subjects in these other case-control pairs a group defined as being at high risk of melanoma by a risk score derived from these five variables contained 60 (54%) of the patients with melanoma but only 18 (16%) of the controls. These data suggest that in Western Australia more than half of all new patients with melanoma arise in an identifiable subpopulation constituting less than one fifth of the whole population. Identifying this subpopulation and screening it regularly for cutaneous malignant melanoma could be cost effective in reducing mortality from this disease.

Adolescent↗
PubMed1988

Diet and blood pressure in 9-year-old Australian children.

Relationships between blood pressure and dietary factors were investigated in 884 9-y-old Australian children. Data on usual diet were obtained from a food frequency questionnaire completed by parents. The data were used to estimate daily energy intake and intakes of 14 nutrients considered to have some potential for influencing blood pressure. Systolic and diastolic blood pressure were tested for relationships with absolute intakes and calorie-adjusted intakes of each nutrient after adjustment for potential confounders. Diastolic pressure in boys was negatively related to energy intake and to calorie-adjusted fiber intake. Mean adjusted diastolic pressure in boys in the top fiber-intake quartile was 2.5 mm Hg lower than that in the bottom fiber-intake quartile. Systolic pressure in girls was negatively related to calorie-adjusted intakes of protein and cholesterol. There were no detectable relationships between blood pressure and calorie-adjusted intakes of fats, carbohydrates, sodium, potassium, calcium, or magnesium.

Australia↗
PubMed1988

Vegetarian diet in mild hypertension: effects of fat and fiber.

Recently, a relatively small reduction in systolic blood pressure (approximately 5 mm Hg) was estimated to substantially reduce the numbers of major coronary events. The blood pressure reduction is about the same as the difference seen between typical ovolactovegetarians and omnivores. This paper reviews the evidence for the blood pressure-lowering effects of a vegetarian diet on those with elevated blood pressure. It also reviews whether the effect on blood pressure of a vegetarian diet can be attributed either to elevation of the dietary P:S ratio or to fiber intake alone.

Adult↗
PubMed1988

Vegetarian diet and blood pressure levels: incidental or causal association?

Evidence that nutrients other than the major cations may influence blood pressure levels stems from studies of acculturated vegetarians and from randomized controlled dietary trials. Earlier studies of vegetarians focused on religious groups and on vegans, making it difficult to know whether their lower blood pressures were due to diet per se or to other aspects of lifestyle. Seventh-day Adventist vegetarians showed significantly less hypertension and lower blood pressures compared with Mormon omnivores, effects which were independent of differences in obesity and not due to altered sodium intake. Subsequently, controlled dietary intervention studies in healthy normotensive omnivores provided more direct evidence for a blood pressure-lowering effect of a lactoovovegetarian diet with reversible changes of 5-6 mm Hg systolic and 2-3 mm Hg diastolic occurring over 6-wk periods. Similar dietary effects in mild hypertensive subjects provides impetus for identifying the responsible nutrients.

Adolescent↗
PubMed1988

Measuring the incidence of acute myocardial infarction: the problem of possible acute myocardial infarction.

Variations in the ratio of "definite" to "possible" myocardial infarction for non-fatal cases were examined in studies that used World Health Organization criteria. There were large variations in this ratio, variations which appeared to be due to differences in the ascertainment of non-fatal cases of "possible" myocardial infarction, which, in turn, contributed to reported differences in the incidence of myocardial infarction. A significant proportion of cases of "possible" myocardial infarction probably do not have ischemic heart disease at all, since, in our data, cases of "possible" myocardial infarction (non-fatal) with a hospital discharge diagnosis of chest pain (undiagnosed) had a risk of death that was no worse than that in the general population. Thus the most reproducible, and possibly most accurate estimates of the incidence of myocardial infarction may come from including only fatal cases of "possible" myocardial infarction with both fatal and non-fatal cases of "definite" myocardial infarction.

Acute Disease↗
PubMed1988

The epidemiology and prevention of cancer in Australia.

Based on the numbers of new cancers diagnosed, deaths from cancer and person-years of life lost as a result of death from cancer, non-melanocytic skin cancer, lung cancer, cancers of the colon and rectum, breast cancer, cancer of the prostate, melanoma, cancer of the stomach, cancer of the bladder, cancer of the pancreas, and non-Hodgkin's lymphoma were judged to be the most important cancers in Australia in 1982. Of these, only cancer of the pancreas appeared to be decreasing in frequency, and then only since 1979, while cancers of the lung and malignant melanoma of the skin were increasing rapidly. By the turn of the century the number of new cases of cancer diagnosed in Australia each year will be at least 50% higher than it was in 1982, mainly as a result of population growth and ageing. Given what is presently known about the causes of cancer it may be estimated that about one-third of cancers occurring in Australia could be prevented through feasible programmes. More than half of this change would be achieved through the elimination of tobacco smoking. A further 13% of cancer deaths, and some non-fatal cases, could be prevented by the effective implementation of cancer screening programmes of established efficacy. Even after this, however, many of the currently important cancers would remain significant. They are, therefore, priority subjects for research in cancer control.

Adolescent↗
PubMed1988

Incidence and outcome of multiple myeloma in Western Australia, 1960 to 1984.

All patients diagnosed with multiple myeloma in Western Australia have been registered since 1960; 337 men and 280 women were registered in the period 1960-84. During this period there was a 25% increase in incidence. Age adjusted incidence rates rose from 2.34 per 100,000 person years in men and 1.64 in women during the decade 1960-69 to 2.95 in men and 1.92 in women in 1980-84. Overall, the incidence was 1.36 times higher in men than in women (95% confidence interval 1.16-1.59). Survival from multiple myeloma improved substantially during the period. In 1960-69, median survival for both sexes was six months, in 1970-79 it was 19 months, and in 1980-84 median survival in men was 43 months while in women it was at least five years.

Agricultural Workers' Diseases↗
PubMed1988

Epidemiology of malignant melanoma: intermittent or total accumulated exposure to the sun?

In accordance with the sunlight hypothesis for its etiology, the incidence of malignant melanoma generally increases with increasing proximity to the equator. There are exceptions to this pattern, prominent among which is the tendency for incidence to increase with increasing distance from the equator beyond latitude 50 degrees north in Europe. This anomaly is probably explicable in terms of climatic factors, geographic variation in skin pigmentation, and the sun-seeking behavior of those in the north. The incidence of malignant melanoma is increasing at about 5% a year in most white populations, while there is no consistent tendency for it to increase in black populations. This difference suggests that the increase is due to increasing sun exposure. Evidence from recent case-control studies is consistent with both intermittent intense exposure and total accumulated exposure to the sun causing an increase in risk of malignant melanoma. Reconciliation of these two different patterns of effect of sun exposure may lie in more careful measurement of sun exposure and analysis of exposure specific to the site at which each melanoma is observed to occur.

Australia↗
PubMed1988

Mortality in miners and millers of crocidolite in Western Australia.

It is known that 6505 men and 411 women were employed in the mining and milling of crocidolite at Wittenoom in the Pilbara region of Western Australia between 1943 and 1966. Employment was usually brief (median duration four months) and exposure intense (median estimated cumulative exposure 6 fibres/cc years). The vital status of 73% of the men and 58% of the women employed in the industry was known at 31 December 1980, providing 95 264 person-years of follow up with 820 deaths in men and 4914 person-years with 23 deaths in women. The standardised mortality ratio (SMR) for all causes in men was 1.53 (95% confidence interval 1.43 to 1.64). Statistically significant excess death rates were observed in men for neoplasms, particularly malignant mesothelioma (32 deaths), neoplasms of the trachea, bronchus, and lung (SMR 2.64), and neoplasms of the stomach (SMR 1.90); respiratory diseases, particularly pneumoconiosis (SMR 25.5); infections, particularly tuberculosis (SMR 4.09); mental disorders particularly alcoholism (SMR 4.87); digestive diseases, particularly peptic ulceration (SMR 2.46) and cirrhosis of the liver (SMR 3.94); and injuries and poisonings, particularly non-transport accidents (SMR 2.36). The excess mortality from pneumoconiosis, malignant mesothelioma, and respiratory cancers, but not stomach neoplasms, was dependent on time since first exposure and cumulative exposure. There was no increase in mortality from laryngeal cancer (SMR 1.09) or neoplasms other than those listed. The SMR for all causes in women was 1.47 (95% confidence interval 0.98-2.21) and for neoplasms 1.99; there was one death from malignant pleural mesothelioma.

Adult↗
PubMed1988

Variation in hospital morbidity in the male workforce of Western Australia.

The associations of hospital morbidity with occupation were studied in Western Australian men of working age in 1981-2. Data on hospital morbidity were derived from a population based system that covered all short stays in hospitals in the state. Occupations were grouped into 12 major categories and conditions were coded using the International Classification of Diseases. Armed services personnel had the highest overall rate of hospital admissions, followed by transport and communications workers and by administrative and managerial workers. Injuries were the most common cause of referral to hospital. Four occupational groups, farmers and allied workers, miners and quarrymen, transport and communications workers, and craftsmen, production workers, and labourers were often associated with injury. Diseases of the musculoskeletal system and connective tissue were the second most common cause for referral and were increased in transport and communications workers, and in craftsmen, production workers, and labourers. Several other associations between causes of hospital admission and major occupational groups were observed, including associations of circulatory system diseases with professional and technical work and with administrative and managerial work. The excess of hospital admissions due to factors associated with occupation was estimated to be 12,665 admissions a year or 24.9% of the total in working men.

Adolescent↗