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Biomedical subjects

A R Feinstein

Publications and source records attributed to A R Feinstein.

At least 199 records · Page 11Linked to original sources
PubMed1983

An additional basic science for clinical medicine: I. The constraining fundamental paradigms.

The four main conceptual paradigms of basic biomedical research are that the explication of mechanisms is a primary goal of science; that scientific data must be "hard"; that formulation of hypotheses and counter-hypotheses is a principal creative challenge; and that experiments are the main mechanism for using scientific methods to conduct investigations. Although suitable for the spectacular accomplishments of biomedical research, these paradigms do not offer a satisfactory foundation for the additional basic science needed in the managerial decisions of patient care. For these decisions, the primary scientific goal is usually prediction rather than explication alone; the crucial data often involve "soft" information about clinical and personal phenomena; and the main creative challenge is to develop an improved methodology for getting adequate data and making unbiased comparisons. Although the experiments conducted as randomized clinical trials have been scientifically helpful, the improved methods will have to include evidence obtained in the often unplanned "experiments" of ordinary clinical practice.

Clinical Trials as Topic↗
PubMed1983

An additional basic science for clinical medicine: II. The limitations of randomized trials.

Although highly successful in investigating remedial therapy, randomized clinical trials have sometimes created rather than clarified controversy when the treatments were given for the complex problems involved in studying either the primary prevention of disease or the secondary prevention of adverse progression for an established disease. Another source of difficulty has been the inevitable conflicts created by two legitimate and justifiable but opposing policies regarding the fastidious or pragmatic goals of the trials. These problems limit the scope of clinical questions that can be answered successfully by randomized trials, but other limitations are produced by problems in logistics or ethics. Randomized trials are unfeasible for studying multiple therapeutic candidates, minor changes in therapy, "instabilities" due to rapid technologic improvements in available treatment, long-term adverse effects, studies of etiologic or other suspected "noxious" agents, and the diverse clinical roles of diagnostic technology. Consequently, despite the magnificent scientific achievements of randomized clinical trials, the foundation for a basic science of patient care will also require major attention to the events and observations that occur in the ordinary circumstances of clinical practice.

Clinical Trials as Topic↗
PubMed1983

An additional basic science for clinical medicine: III. The challenges of comparison and measurement.

The main scientific virtue of randomized allocation of treatment is an unpredictability that reduces susceptibility bias in the groups created when treatments are assigned preferentially according to prognostic differences. Even in randomized trials, however, prognostic analyses are needed for checking imbalances in the randomization, for precise clinical application of results, and for discerning disparate therapeutic effects. Improved methods of prognostic analyses can enhance effectiveness in randomized trials and credibility for nonrandomized therapeutic comparisons. Regardless of randomization, therapeutic comparisons will also be improved with better analysis of proficiency for the main treatments, better attention to identifying "soft" clinical outcome events, and development of new analytic structures for complex problems in logistics. The challenges will require better scientific methods for the two types of clinical measurement: the mensuration with which descriptive expressions are provided for individual observations; and the quantification with which individual descriptions are grouped, summarized, and compared.

Humans↗
PubMed1983

An additional basic science for clinical medicine: IV. The development of clinimetrics.

The domain of clinimetrics is concerned with quantitative methods in the collection and analysis of comparative clinical data, and particularly with improved "measurement" of the distinctively clinical and personal phenomena of patient care. The main requirement for scientific quality in data is a consistent, reproducible process of observation and expression. This requirement can be attained with appropriate attention to basic descriptive activities and to the operational criteria that convert raw descriptions into the variables, categories, and composite aggregates of suitably chosen clinimetric scales. For this work, clinicians will be challenged to "dissect" and stipulate the components of decisions that are now made with unspecified methods or judgments. Clinimetric science provides opportunities for new approaches, new sites, and new personnel in an additional type of clinical investigation that can augment the scientific basis of clinical practice, while rehumanizing the contents of research data and restoring analytic emphasis to the art of patient care.

Data Collection↗
PubMed1982

Double standards, scientific methods, and epidemiologic research.

Because suspected noxious agents can seldom be tested experimentally in people, epidemiologic investigation of the causes of disease depends on observational procedures, of which the most prominent types are cohort and case-control studies. In these studies the compared agents cannot be assigned experimentally, but many other basic experimental principles that could be employed are often overlooked, including verification of quality and accuracy in raw data, avoidance of major biases in comparison, vigilance in checking for methodologic errors, and maintenance of a careful distinction between research data that generate hypotheses and the new data needed to test these hypotheses. The problems that result when these principles are overlooked can be alleviated if etiologic research is performed and evaluated with the same standards used in other branches of science.

Diagnosis↗
PubMed1982

The limited spectrum of patients studied in exercise test research. Analyzing the tip of the iceberg.

To investigate reasons for the wide variation in formal studies of sensitivity and specificity indexes for the diagnostic efficacy of the graded exercise test for angiographically defined coronary disease, data were collected on 205 consecutive exercise tests at two hospital-based exercise laboratories. For calculations of sensitivity and specificity, stress test data are usually analyzed with many exclusions for ineligibility, with equivocal results omitted, and only in patients undergoing angiography. Consequently, only 3% of patients who received the tests in this survey would have been included in a typical formal study of diagnostic efficacy. In the same way that the visible tip of an iceberg misrepresents its extent and depth, the patients assembled in studies of diagnostic tests may be a highly selected group that misrepresents the intended population.

Coronary Angiography↗
PubMed1982

A controlled evaluation of the risk of bacterial endocarditis in persons with mitral-valve prolapse.

The absence of controlled evidence and the high prevalence of mitral-valve prolapse have created substantial uncertainty about whether this condition is an important risk factor for bacterial endocarditis. We evaluated this risk in a case-control study of hospital inpatients who had undergone echocardiography and who lacked any known cardiovascular risk factors for endocarditis, apart from mitral-valve prolapse and isolated mitral-regurgitant murmurs. Thirteen (25 per cent) of 51 patients with endocarditis had mitral-valve prolapse, as compared with 10 (seven per cent) of the 153 matched controls without endocarditis. For the 51 matched case-control sets, the odds ratio (8.2; 95 per cent confidence interval, 2.4 to 28.4) indicated a substantially higher risk of endocarditis for people with mitral-valve prolapse than for those without it. This association remained statistically significant when parenteral drug abuse and routine antibiotic prophylaxis preceding dental work and other forms of instrumentation were taken into account. Furthermore, the risk may be higher than is indicated by this study, since 46 per cent of the controls underwent echocardiography for clinically suspected mitral-valve prolapse, suggesting an overrepresentation of mitral prolapse in the control group. The results support the contention that mitral-valve prolapse is a significant risk factor for bacterial endocarditis.

Adult↗
PubMed1982

Toxic shock and tampons. Evaluation of the epidemiologic evidence.

The main evidence that tampons are an etiologic cofactor in the development of toxic shock syndrome (TSS) comes from epidemiologic case-control studies. The patients chosen as cases in those studies were assembled from reports submitted to health agencies in response to publicity that may have influenced physicians to diagnose TSS and to submit reports particularly in situations where the patient was a menstruating tampon user. When the submitted reports were checked for fulfillment of TSS diagnostic criteria, and when cases or controls were asked about antecedent tampon usage, suitable scientific precautions were not used to achieve "blinded" objective decisions. Since these biases would have distorted the statistical relationships, the etiologic role of tampons in TSS has not been scientifically proved.

Clinical Trials as Topic↗
PubMed1982

Rapid growth rate in breast cancer: a confounding variable in adjuvant-chemotherapy trials.

In randomised trials of adjuvant chemotherapy for node-positive breast cancer, significant benefits has been seen in premenopausal but not postmenopausal patients. A possible explanation for this distinction is that premenopausal groups contain a greater proportion of patients with rapidly growing tumours that respond well to chemotherapy. The purpose of this study was to assess the plausibility of this explanation, using a clinical index to estimate rate of growth. From a cohort of women with primary breast cancer, none of whom had received adjuvant chemotherapy, an adjuvant-treated population was simulated by means of a study of the 164 patients who would have been eligible for entry into an adjuvant trial. The prognosis for each patient was categorised according to premenopausal or postmenopausal status, nodal status (1-3 or greater than or equal to 4), and growth rate of the cancer (non-rapid or rapid). Patients with rapid growth rates comprised a greater proportion of the premenopausal group (32%) than of the postmenopausal group (20%). On the assumption that adjuvant chemotherapy would preferentially benefit the rapid-growth stratum, the potential impact of the disproportionate distribution of the rapid-growth-rate stratum on the results of adjuvant trials was calculated. The results showed that a disparity in distribution of the rapid-growth-rate stratum could account for the apparently greater benefit in premenopausal patients.

Age Factors↗
PubMed1981

Improved observational method for studying therapeutic efficacy. Suggestive evidence that lidocaine prophylaxis prevents death in acute myocardial infarction.

Criteria for patient eligibility in a randomized clinical trial can be used to improve the design of observational case-control studies. The new strategy has been illustrated in a case-control investigation of whether lidocaine prophylaxis prevents death in patients with acute myocardial infarction. From among patients hospitalized with myocardial infarction in a special care unit during 1974 to 1978, there were 151 fatalities (cases) and 151 survivors (controls) selected for study. After removal of the ineligible cases and controls, lidocaine prophylaxis was found to have no effect on death from pump failure or nonarrhythmic causes, but was significantly protective against death from ventricular arrhythmias, particularly in patients with congestive heart failure. If confirmed by rigorously designed longitudinal studies, the improved case-control technique could serve as a useful "screening' device to assess the efficacy of medical or surgical treatments that cannot be tested with randomized clinical trials.

Acute Disease↗
PubMed1981

Histopathologic distinctions in the relationship of estrogens and endometrial cancer.

The slides of 233 patients included in a case-control study of estrogens and endometrial cancer were reviewed to determine how often endometrial cancer was misdiagnosed and whether patients with uterine cancer had other coexistent endometrial diseases. Reasonably close agreements were found among the original diagnoses and those of three additional reviewers (the total range of disagreements among all pathologists was from 2% to 16%). Proliferative and hyperplastic endometrium coexisted in many specimens from patients with endometrial cancer, and especially in those who had used estrogen replacement therapy. In contrast, estrogen therapy had seldom been used by patients whose cancers were not accompanied by these proliferative and hyperplastic lesions. In addition, these changes were found significantly more often in women with grade 1 cancers than grade 2 or 3 cancers. We conclude from these data that diagnostic misclassification is uncommon and that coexistent proliferative and hyperplastic lesions occur frequently, especially among women with grade 1 cancers. The data also suggest that the frequent finding of grade 1 cancer in estrogen users is due to bleeding that results from the stimulated coexistent benign proliferating endometrium.

Endometrial Hyperplasia↗