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A R Dyer

Publications and source records attributed to A R Dyer.

At least 109 records · Page 6Linked to original sources
PubMed1979

A rank statistic for assessing the amount of variation explained by risk factors in epidemiologic studies.

A statistic, Q, based on the ranks of the estimated probabilities of disease is proposed for assessing the effectiveness of regression models used with dichotomous dependent variables in epidemiologic studies of risk factors for chronic diseases. The pitfalls of R2 are discussed, and the proposed statistic is compared with R2 utilizing 8.6-year incidence data from the national cooperative Pooling Project and 15-year mortality data from the Chicago Peoples Gas Company Study. Based on the risk factors, systolic blood pressure, serum cholesterol, and smoking status for middle-aged males, the proposed statistic, Q, attains from 27-44% of its maximum value for the endpoint, the first major coronary event, and from 35-46% of the maximum for death from the cardiovascular diseases.

Adult↗
PubMed1979

Racial patterns of heart rate in an employed adult population.

This study explored racial patterns of heart rate in a large population of employed Chicagoans: 39,665 adults screened in Chicago firms between late 1967 and early 1973. Of these, 30,876 were white or black adults age 18--64 with complete data, and not on drug therapy for hypertension. Mean heart rates of young black men and women were significantly lower than mean heart rates of young white men and women. This difference was not present for the age groups 35 and older. The difference was present in both smokers and non-smokers; in normotensives and in persons with elevated blood pressure; and could not be explained by differences in relative body weight. The difference persisted after simultaneous adjustment for differences in the mean values of systolic blood pressure, relative weight, serum cholesterol, post-loaded plasma glucose, and number of cigarettes smoked per day.

Adolescent↗
PubMed1979

Uric acid: a risk factor for coronary heart disease?

The association between serum uric acid and the prevalence of ECG abnormalities was analyzed for 24.997 employed men and women, white and black, age 18--64 years, from the Chicago Heart Association (CHA) Detection Project in Industry. In addition, the relationships between uric acid and 5-year mortality from all causes, from cardiovascular diseases (CVD), and from coronary heart disease (CHD) were analyzed for 7804 white men and women age 45--64 years from this study and 967 white men age 44--63 years from the Chicago People's Gas Company Study. For men, the association between uric acid and the prevalence of ECG abnormalities and with mortality appear to be secondary to associations between uric acid and other risk factors. For women, however, the associations could not be explained by other risk factors.

Arrhythmias, Cardiac↗
PubMed1977

Hypertension in the elderly.

The available data indicate that classical hypertension, defined here as a diastolic blood pressure greater than or equal to 95 mm Hg, is a widely prevalent and as important a risk factor for the cardiovascular diseases in those aged 65 and over as it is in those under 65. The limited available data also indicate that pure systolic hypertension, defined here as a systolic blood pressure exceeding 160 mm Hg with a diastolic pressure under 95 mm Hg, also very common at age 65 and over, is also related to excess cardiovascular morbidity and mortality in the elderly. However, it is not clear whether this latter relationship is indicative of cause and effect, or merely reflects the fact that in the elderly pure systolic hypertension is a sign of extensive sclerosis of large arteries. The results of Veterans Administration studies on antihypertensive therapy indicate that the elderly patient with classical hypertension is amenable to effective treatment, and that the benefits of such treatment significantly outweigh the risks. Great care is needed in the use of drugs for the management of hypertension in elderly patients, especially to minimize risk of hypotensive episodes and their possible harmful consequences; but with judicious and careful therapy, hypertension of this type can be controlled with reduction in excess risk of morbidity and mortality, at least for those with average diastolic pressures greater than or equal to 105 mm Hg. The lack of data on the benefits of treatment for those with pure systolic hypertension precludes any recommendations in regard to pharmacologic treatment of this condition.

Adult↗
PubMed1977

Alcohol consumption, cardiovascular risk factors, and mortality in two Chicago epidemiologic studies.

Multivariate analysis of the association at baseline between problem drinking and cardiovascular risk factors among 1,233 white male employees of the Chicago Peoples Gas Company age 40-59 showed the 38 problem drinkers with significantly higher blood pressures and cigarette consumption and significantly lower relative weights than the others. Similar analysis among 1,899 white male employees of the Hawthorne Works of the Western Electric Company in Chicago age 40-55 showed the 117 men consuming 5 or more drinks per day with significantly higher blood pressures and cigarette use than the others. No significant differences were recorded between heavy drinkers and the others in serum cholesterol level. The gas company problem drinkers had significantly higher 15-year mortality rates from all causes, cardiovascular diseases, coronary heart disease, and sudden death. These differences could not be entirely explained by their blood pressure, smoking, and relative weight status. The Western Electric heavy drinkers had increased 10-year mortality rates both for all causes and noncardiovascular causes.

Adult↗
PubMed1976

The relationship of education to blood pressure: findings on 40,000 employed Chicagoans.

The relationship of education to both actual blood pressure and the prevalence of high blood pressure, based on a systolic pressure of 160 mm Hg or greater or a diastolic pressure of 95 mm Hg or greater, was analyzed among 27,033 men and women, white and black, age 25-44 and 45-64, from the Chicago Heart Association Detection Project in Industry. The educational status of each individual was categorized as not a high school graduate, high school graduate, some college, or college graduate. A statistically significant inverse association between education and high blood pressure was present in all groups of whites. This association could not be "accounted for" by differences in age, relative weight, and heart rate among the educational strata. Controlling for these variables did, however, lessen the association. Among black males a significant inverse association between education level and blood pressure was found for the younger group. For the older black males there was a clear inverse association although with the small numbers it did not achieve statistical significance. For black females there was no clear association.

Adult↗
PubMed1975

High blood-pressure: a risk factor for cancer mortality?

Univariate and multivariate analyses have been made of the relationship of systolic and diastolic blood-pressure measured at study entry to subsequent 14-year mortality among 1233 White males originally age 40-59 in 1958 from the Chicago Peoples Gas Company prospective study. With age, serum-cholesterol, and cigarettes per day controlled, both elevated systolic and electaed diastolic blood-pressure in 1958 were found to be strongly related to subsequent mortality from cancer in the men of this study. The possibility that this finding was due either to an association between antihypertensive medication in general, and cancer, or to an association was found that could explain the excess cancer mortality among those with elevated blood-pressure in 1958, either with medication in general, or with reserpine and rauwolfia in particular. These findings thus pose the question, is high blood-pressure associated with an increased risk of death due to cancer?

Adult↗
PubMed1975

Prevalence of intestinal parasites in Latino residents of Chicago.

In 1970, 250,000 Spanish-speaking persons resided in Chicago, 80,000 of whom were Puerto Rican. Because migration to Chicago is constantly occurring from areas where intestinal parasites are endemic, a survey was conducted in a predominantly Puerto Rican neighborhood to determine the prevalence of these parasites and to provide impetus for further case finding and treatment programs. The survey was part of an epidemiologic and cutreach workers going door-to-door obtained histories, hematocrits, and single stool specimens from 358 individuals. An overall intestinal parasite prevalence rate of 18.6% (67 persons) was found. Specific rates were Trichuris trichiura 13.9% (50 cases), hookworm 6.6% (24 cases), Giardia lamblia (3.9% (14 cases), and Strongyloides stercoralis 1.7% (6 cases). There were no cases of Ascaris lumbricoides or ENTAMOEBA HISTOLYTICA, Although several nonpathogenic protozoa were found. The most affected age groups were 15--24 years followed by 5--14. Two of the Giardia cases were individuals never out of the continental United States. An incidental finding was a high rate of low hematocrit readings not correlated with the parasite findings.

Adolescent↗
PubMedDate not supplied

A method for combining results from several prospective epidemiologic studies.

An approach to the problem of a single study lacking adequate power to examine an important question is to combine the data from several studies to allow a more powerful test of the hypothesis in question. The present paper describes a method used by the International Collaborative Group to pool data on 54,492 men aged 40-69 from 10 population studies in 7 countries to examine the association between cholesterol level and risk of death from cancer. Furthermore, there was a suggestion that the inverse association observed in some studies might be the result of an effect of undetected cancer on cholesterol level, rather than an increase in cancer risk resulting from low cholesterol levels. This paper describes the process for selection of the method used to evaluate this possibility over other potential approaches and the results obtained in the analysis of the International Collaborative Group data that support this hypothesis. This report also indicates how one might expect some of the analyses described to compare with analyses based on a discrete version of the Cox proportional hazards model.

Aged↗