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Biomedical subjects

J A Baron

Publications and source records attributed to J A Baron.

At least 163 records · Page 9Linked to original sources
PubMed1989

Cholesterol and coronary heart disease. The attributable risk reduction of diet and drugs.

The efficacy of treating hypercholesterolemia is often expressed in relative terms as the ratio of risk in treated vs untreated populations. However, the clinical impact of treatment is best measured by the difference in risk, which is called the attributable risk reduction. Attributable risk reduction is most useful clinically if it is reported for specific subgroups of patients according to age, sex, and other risk factors. To illustrate this concept, its applications and limitations, we review the literature on the primary and secondary treatment of hypercholesterolemia, present the attributable risk reduction, and describe its implications for clinical practice.

Coronary Disease↗
PubMed1988

Social and economic factors in the choice of lung cancer treatment. A population-based study in two rural states.

We reviewed 1808 hospital charts representing virtually all patients given a diagnosis of non-small-cell lung cancer in New Hampshire and Vermont between 1973 and 1976 and found that the treatment of patients varied according to their marital status, medical insurance coverage, and proximity to a cancer-treatment center. Patients were more likely to be treated with surgery if they were married (odds ratio, 1.67; 95 percent confidence interval, 1.08 to 2.57) or had private medical insurance (1.52; 1.03 to 2.26). Among patients who did not have surgery, those with private insurance were more likely to receive another form of anticancer therapy--either radiation or chemotherapy (1.57; 1.18 to 2.09). Residing farther from a cancer-treatment center was associated with a greater chance of having surgery. Patients 75 years of age and older were less likely to have surgery (0.16; 0.08 to 0.35) or any other tumor-directed therapy (0.32; 0.19 to 0.54). The relation between the type of treatment and a patient's characteristics was not based on apparent differences in tumor stage or functional status, although both these factors were also strongly predictive of the type of treatment. Despite the fact that privately insured and married patients were more aggressively treated, they did not survive longer after diagnosis. We conclude that for non-small-cell lung cancer, socio-economic as well as medical factors determine treatment.

Age Factors↗
PubMed1988

Cigarette smoking and other correlates of cytologic estrogen effect in postmenopausal women.

Cigarette smoking and other factors associated with estrogen-related diseases may influence risk through hormonal mechanisms. To investigate the sex hormone associations of these risk factors, vaginal scrape cytology specimens and questionnaire data were obtained on 215 postmenopausal women at the time of routine pelvic examination. All specimens were read blindly by one cytologist, and the relationships between the indices of maturation and risk factors were assessed with regression techniques. Current cigarette smoking and obesity were associated with increased maturation. In contrast, years past menopause, parity, and coffee and tea consumption were all unrelated to vaginal epithelial maturation. These results elucidate the mechanisms underlying the antiestrogenic effect of cigarette smoking and support the concept that obesity is associated with an estrogenic effect.

Aged↗
PubMed1988

Cholesterol and coronary heart disease. The importance of patient-specific attributable risk.

The value of treating hypercholesterolemia remains controversial despite extensive investigation, in part because of the research orientation of much of the relevant literature. Most published studies report relative measures of risks such as the risk ratio. However, clinicians are concerned with the magnitude of risk, or attributable risk, the difference in risk in those with highest and lowest serum cholesterol levels. Since maximum risk modification is rarely achieved, the attributable risk often overstates the potential benefit of risk factor reduction. A variant of the attributable risk, the practical attributable risk, gives a more realistic estimate of potential benefit. Since clinicians treat individuals and not populations, these measures of risk are most useful if reported for subgroups of patients (eg, men and women, as well as those of varying age). To illustrate these concepts, we review the literature on hypercholesterolemia, report the risk ratio, attributable risk, and practical attributable risk for important patient populations, and discuss the implications for clinical practice.

Age Factors↗
PubMed1987

Sex hormones and coronary artery disease.

Previous investigators have found an increased risk of coronary heart disease in men with high levels of circulating estrogens. To elucidate further this relationship, a case-control study of atherosclerotic coronary artery disease (ASCAD) and sex hormones was undertaken in male patients. Hormone levels in men with severe ASCAD documented at angiography were compared with those in men found to be virtually free from disease and with those in a group of control subjects without signs or symptoms of ASCAD. Significantly lower total testosterone levels were observed among men with severe ASCAD compared with either control group; the free testosterone level was significantly lower than in angiographically disease-free control subjects. The same pattern of hormone levels persisted after control of covariates. Epidemiologic analysis demonstrated a fivefold decrease in risk for severe ASCAD between the lowest and the highest quartile of total testosterone. No overall pattern of association was seen between ASCAD and free or total estrogens.

Adult↗
PubMed1987

Risk factors for endemic giardiasis.

In a mail survey, 171 Hitchcock Clinic patients with giardiasis were compared with an age- and sex-matched control group of 684 clinic patients with respect to potential risk factors. Households with shallow well or surface water sources had an odds ratio (OR) for giardiasis of 2.1 (95% confidence interval (95%CI) 1.3-3.2) compared with households with drilled well or municipal water supply. Other observed risks include family member in day care program (OR 2.2 95%CI 1.3-3.7) and family member with diagnosed giardiasis (OR 17, 95%CI 7.4-37). Previously reported risks such as travel out of country (OR 3.2, 95%CI 1.5-7.2) and camping (OR 1.7, 95%CI 0.9-3.2) were also observed. Virtually no giardiasis risk was observed associated with report of dog or barnyard animal proximity. Control for confounding and adjustment for recall and non-response bias does not materially alter the risk estimates. We suggest that shallow well or surface household water source is an important and previously unrecognized giardiasis risk factor.

Adolescent↗
PubMed1986

Cigarette smoking in women with cancers of the breast and reproductive organs.

This case-control study addressed the relationship between cigarette smoking and cancers of the breast (1,741 cases), endometrium (476 cases), uterine cervix (1,174 cases), and ovary (296 cases). The lifetime smoking history of cases was compared with that of 2,128 controls, and relative risks (odds ratios) for smoking were estimated using multiple logistic regression to adjust for potential confounding by age, marital status, number of pregnancies, and Quetelet's index. With increasing amount smoked there was a statistically significant decrease in endometrial cancer risk and a statistically significant increase in cervical cancer risk. In the highest smoking category (greater than or equal to 15 pack-yr), the endometrial cancer relative risk was 0.57 [95% confidence interval (CI) of 0.37, 0.86] and the cervical cancer relative risk was 1.81 (95% CI of 1.47, 2.22). There was no apparent relationship between smoking and cancers of the breast or ovary.

Adult↗
PubMed1986

Cigarette smoking and Parkinson's disease.

Epidemiologic evidence has suggested a negative association between cigarette smoking and the risk of Parkinson's disease. Although many of the studies had limitations, in aggregate they suggest that smoking may actually be a protective exposure. Other lines of evidence support this view, especially animal data indicating a dopaminergic effect of smoking on the brain.

Brain↗
PubMed1986

A randomized controlled trial of low carbohydrate and low fat/high fiber diets for weight loss.

Among 135 overweight subjects, we conducted a three-month randomized controlled trial of two sets of dietary advice, each providing approximately 1,000 calories per day but differing in fiber, carbohydrate, and fat content. Information on weight and eating habits, as well as measures of lipoprotein and glucose metabolism were obtained at entry and one and three months later. We found that dieters given low carbohydrate/low fiber dietary advice tended to lose more weight than those given a higher carbohydrate/higher fiber regimen (5.0 vs 3.7 kg on average at three months). This pattern was particularly marked among women, and among participants who were under age 40 or of lower social class. There were no differences between the diet groups in the proportion complaining of hunger but, in general, members of the low carbohydrate group complained of more problems in dieting. There were only minor differences in the serum lipoprotein patterns during the diet period. In view of these results, we believe previous claims of the benefits of fiber for weight loss may have been overstated.

Adult↗
PubMed1984

Cancer mortality in small areas around nuclear facilities in England and Wales.

Cancer mortality trends were examined for the small areas around fourteen nuclear and five non-nuclear facilities in England and Wales. Using routine OPCS mortality data, standardized mortality ratios (SMRs) for these areas were computed for selected causes of death. Changes in the SMRs were then sought by comparing the SMRs for the five years before the facility opened with the period 10 (in some cases 15) years after start-up, and by computing the weighted regression of the SMRs on calendar year. These analyses indicate no overall pattern of increasing cancer SMRs around nuclear facilities.

Adolescent↗
PubMed1984

Incidence of lung cancer by cell type: a population-based study in New Hampshire and Vermont.

Identified were 1,906 cases of confirmed lung cancer that occurred among all residents of New Hampshire and Vermont over a 4-year period. Medical records, pathologists' reports, and, when possible, pathology slides were obtained and reviewed to assign cases to a specific histologic diagnosis. The diagnosis made by the original pathologist was generally confirmed upon review, except for the large cell undifferentiated cell type which appeared to be an unreliable classification. Among men at all ages incidence rates for squamous cell cancer far exceeded those for adenocarcinoma and small cell undifferentiated carcinoma, and the three age-incidence curves showed a similar pattern, rising until the eighth decade of life and then declining. Among women these three major cell types occurred about equally often, but the age-incidence curves differed in shape with adenocarcinoma reaching a peak incidence at an earlier age.

Adenocarcinoma↗
PubMed1984

Maternal age and breast cancer risk.

Maternal age at time of birth was investigated as a risk factor for breast cancer in a study of 1,176 matched case-control pairs. There was no pattern of increasing adjusted relative risk of breast cancer with increasing maternal age, nor was the mean maternal age of cases older than that of controls. Similar negative results were found among the subset of subjects up to 35 years old, a group previously found to show marked maternal age effects. Thus previous reports of an association between breast cancer and advanced maternal age may have been due to chance, extraneous factors, or a misleading reliance on unadjusted mean maternal ages, rather than on relative risks.

Adult↗
PubMed1983

Reye's syndrome. A review from the forensic viewpoint.

Reye's syndrome, encephalopathy and fatty change in the liver and other viscera, typically occurs suddenly in infants and children recovering from a viral illness, particularly influenza or varicella. Its rapid clinical course may suggest a drug-related insult and the differential diagnosis includes a variety of toxins. There are grounds for suspicion that exogenous substances--including aspirin--may be cofactors with recent viral illness in the syndrome's pathogenesis. For these reasons, medical examiners may be called upon to rule the diagnosis in or out, to assess the possibility of direct toxic injury, or to document presence or absence of possible cofactors. With these tasks in mind, this review summarizes the diagnostic, pathologic, and laboratory findings of Reye's syndrome and considers the roles of viral infection, heritable predispositions, and exogenous toxins in its causation. It singles out salicylate treatment for special considerations as a possible cofactor, and concludes with a suggested approach to the forensic medical investigation of possible cases of Reye's syndrome.

Aflatoxins↗