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Biomedical subjects

A R Feinstein

Publications and source records attributed to A R Feinstein.

At least 253 records · Page 14Linked to original sources
PubMed1979

Intravaginal estrogen creams and endometrial cancer: no causal association found.

In two case-control studies of estrogens and endometrial cancer, women were asked about previous use of intravaginal estrogen creams. In a set of cases and controls chosen by conventional procedures from a tumor registry, the odds ratio was 0.90. In an alternative set of cases and controls who had all received dilatation and curettage or hysterectomy, the odds ratio was 0.82. Despite the reported relationship between oral estrogens and endometrial cancer and although intravaginal estrogen creams are readily absorbed by the vaginal mucosa, we detect no causal association for their use.

Connecticut↗
PubMed1979

Anticoagulants and myocardial infarction. The problems of pooling, drowning, and floating.

The time and expense required for adequate-sized, randomized control trials may often tempt investigators to try to answer long-standing clinical questions by retrospective analysis of data combined from old studies. In a recent example of such "pooling," the authors concluded not only that anticoagulation is beneficial in acute myocardial infarction but also that further experimental trials would be unethical. This conclusion can be disputed because of scientific, statistical, and clinical standards that were not fulfilled in the "pooled" analysis. Scientifically, the pooling of data from different sources can be valid only if the component studies contain patients who are sufficiently similar in diagnosis, clinical severity, principal treatment, and outcome events. Mathematically, exact numbers rather than percentages should be pooled. Clinically, even when the pooling process is appropriate, recent changes in ancillary therapy may negate the applicability of the old data to current medical practice.

Anticoagulants↗
PubMed1979

Pretherapeutic morbidity in the prognostic staging of acute leukemia.

To classify the clinical severity of acute leukemia, we have used the degrees of pretherapeutic infection and hemorrhage to construct a taxonomy containing three "stages". The stages are associated with survival gradients that are clinically and statistically distinctive in both acute lymphoblastic leukemia and acute nonlymphoblastic leukemia. Median survival ranged from 64.0 months for stage 1 to 10.5 months for stage 3 in acute lymphoblastic leukemia, and from 7.1 months for stage 1 to 1.2 months for stage 3 in acute nonlymphoblastic leukemia. The gradients, which persist when other prognostic factors and secular therapeutic changes are taken into account, are more distinctive than those found with other forms of stratification.

Acute Disease↗
PubMed1979

Analysis of clinical susceptibility bias in case-control studies. Analysis as illustrated by the menopausal syndrome and the risk of endometrial cancer.

Epidemiologic studies of causes of disease rarely contain adjustments for inequalities in diseases susceptibility caused by baseline differences in clinical phenomena. In the controversial association between estrogens and endometrial cancer, the menopausal syndrome was suspected as an independent risk factor for the development of endometrial cancer, irrespective of estrogen use. To investigate this suspicion, personal interview data from a case-control investigation were collected and analyzed. The odds ratio for the association between menopausal symptoms and endometrial cancer was 1.12 and 0.85 for two different sets of cases and controls assembled at the same institution. When the data were partitioned according to estrogen usage, the odds ratios became consistently less than one. The results suggest that the menopausal syndrome is not a risk factor for endometrial cancer.

Aged↗
PubMed1978

Alternative analytic methods for case-control studies of estrogens and endometrial cancer.

In a case-control study of estrogens and endometrial cancer, alternative sampling methods were used to eliminate the detection bias that arises from the increased diagnostic attention received by women with uterine bleeding after estrogen exposure. In a set of cases and controls chosen by conventional procedures the odds ratio was 11.98. In an alternative set of cases and controls at the same institution, consisting of patients who had all received dilatation and curettage or hysterectomy because of uterine bleeding, the odds ratio was 1.7. A methodologic analysis demonstrates detection bias arising from the pattern of hospital referral and shows the way in which the bias is neglected or increased by conventional sampling procedures, but reduced by the alternative procedure. The magnitude of the association between estrogens and endometrial cancer has been greatly overestimated because of detection bias; when an appropriate compensation for the bias is introduced, the odds ratio approaches a value much closer to 1.

Aged↗
PubMed1978

Problems of spectrum and bias in evaluating the efficacy of diagnostic tests.

To determine why many diagnostic tests have proved to be valueless after optimistic introduction into medical practice, we reviewed a series of investigations and identified two major problems that can cause erroneous statistical results for the "sensitivity" and "specificity" indexes of diagnostic efficacy. Unless an appropriately broad spectrum is chosen for the diseased and nondiseased patients who comprise the study population, the diagnostic test may receive falsely high values for its "rule-in" and "rule-out" performances. Unless the interpretation of the test and the establishment of the true diagnosis are done independently, bias may falsely elevate the test's efficacy. Avoidance of these problems might have prevented the early optimism and subsequent disillusionment with the diagnostic value of two selected examples: the carcinoembryonic antigen and nitro-blue tetrazolium tests.

Bacterial Infections↗