American journal of epidemiology
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Pregnancy histories of women interviewed as normal population controls during 1974-1981 in four case-control studies in the US and Canada were examined to identify risk factors for the occurrence of miscarriage. In total, 2,068 ever-gravid women aged 20-79 years at interview (mean age, 50.3 years) described 6,282 pregnancies, including 805 miscarriages. The roles of previous pregnancy history, age at pregnancy, and other factors were evaluated using relative risk binomial regression methods (similar to logistic regression). ⋯ Risk of miscarriage did not appear to be associated with years since previous pregnancy, height, weight or obesity, use of oral contraceptives within one year before pregnancy, or duration of oral contraceptive use. A slight increase in risk was seen for women who had ever regularly smoked cigarettes (relative risk = 1.14, 95 per cent confidence limits = 1.00, 1.30). Thus, the levels of risk of miscarriage found in this analysis are similar to those of previous studies, and the analytic methods suggest how age, obstetric history, and other factors can be simultaneously examined for associations with such risk.
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The authors cultured 2,320 patients who attended the Denver Metro Health Clinic for Sexually Transmitted Diseases from September 1981 to June 1983 to determine clinical and epidemiologic factors associated with genital chlamydial infection. Among consecutive heterosexual men with urethral discharge, 226 of 849 (27%) had positive urethral cultures, with rates significantly lower among those with profuse (18%) or purulent (19%) discharges, and higher (37%) among those with symptoms for more than seven days. In a subgroup of men without gonococci, those who had polymorphonuclear leukocytes on smear had higher isolation rates (33%) than those who did not (3%). ⋯ Younger age was significantly associated with chlamydial isolation in both men and women after controlling for sexual activity and other factors. Various patient characteristics can be combined to define subgroups of men and women, with rates of isolation ranging from under 4% to over 60%. These results can be useful in deciding whom to test and whom to treat presumptively in a public health setting.
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In a previous study, the authors reported a 45 per cent decline in ischemic heart disease mortality between cohorts selected to be representative of Alameda County, California, in 1965 and 1974. The decline could not be explained by baseline differences in the distribution of many of the known ischemic heart disease risk factors available for analysis in this cohort. This study reports the results of further analyses which evaluated the hypothesis that early detection and improved treatment contributed to the decline. ⋯ These interactions were independent of each other and were not explained by adjustment for physical activity, smoking, social connections, or body mass index. There was an increase in the prevalence of self-reported heart trouble between 1965 and 1974, especially among younger age groups. These results are consistent with the hypothesis that early detection and treatment contributed to the decline in ischemic heart disease mortality observed in the Alameda County Study.
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The relations between coffee consumption and 19-year mortality from all causes, coronary heart disease, and non-coronary causes were assessed in 1,910 white males aged 40-56 years in 1957-1958 from the Chicago Western Electric Company Study. Mortality rates, adjusted for age, serum cholesterol, diastolic blood pressure, and smoking status, were compared for those consuming 0-1, 2-3, 4-5, and 6+ cups of coffee per day; coffee intake, measured at the first anniversary examination, included both caffeinated and decaffeinated intake. Mortality from all causes was greatest in the highest and lowest intake groups. ⋯ This increased risk of coronary heart disease death was present in both smokers and nonsmokers, with adjusted relative risks of 1.62 and 2.21, respectively (95 per cent confidence limits 1.17, 2.24 and 1.06, 4.62). The increased mortality from non-coronary causes in the lowest intake group was due primarily to increased mortality from cancer and cardiovascular diseases other than coronary heart disease. The results of this study support the hypothesis that those who drink 6+ cups of coffee per day may be at an increased risk of death from coronary heart disease.