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Biomedical subjects

A Fink

Publications and source records attributed to A Fink.

At least 109 records · Page 6Linked to original sources

Derivation of clinical indications for carotid endarterectomy by an expert panel.

We used a two-round consensus panel method to derive and rate the appropriateness of comprehensive sets of detailed clinical indications for performing carotid endarterectomy. Before meeting, nine nationally influential physicians rated 675 indications; after review and discussion, they rated 864. The method did not force unanimity; our purposes were not only to encourage agreement but also to uncover areas of disagreement concerning the procedure's appropriate use. The panelists agreed on the level of appropriateness for 54 per cent of the final 864 indications and disagreed on 18 per cent. Ratings were reliably reproduced six to eight months after the completion of the process. The physicians' indications and ratings were consistent with those in the literature, and statistical analysis demonstrated that they followed logical clinical rationale. We conclude that consensus methods that do not force agreement can be used with panels of physicians to produce detailed, reliable, and valid indications. They can also identify medically controversial reasons for using a procedure that can serve as a starting point for a research agenda.

Carotid Arteries↗

Educating physicians and treating patients in the ambulatory setting. Where are we going and how will we know when we arrive?

We evaluated 15 group practices in general internal medicine in university hospitals with regard to access to and quality of care, patients' satisfaction with that care, and quality of residency education provided. We used these data to speculate about potential changes in ambulatory care programs in university teaching hospitals. All 15 practices participated for 4 years. One third of their patient population had no medical insurance. Practice patients had twice as many chronic illnesses as did the general population, and two fifths of patients stayed at least 2 years in the practice. Few faculty members spent more than 14 hours weekly in the practices, and housestaff worked an average of 4 hours per week. Patient waiting times did not meet ideal standards, but patient satisfaction was higher than in a general population. Compliance with quality of care criteria was not exceptional; for example, 10% of eligible patients received an annual influenza vaccination. Housestaff assigned a relatively low ranking to their educational experience in the practices. We recommend the institution of additional experimental programs in ambulatory care and housestaff education to improve the quality of care in the ambulatory setting.

Continuity of Patient Care↗

Providing primary general medical care in university hospitals: efficiency and cost.

Data on efficiency, costs, and profits of 15 internal medicine outpatient group practices in university hospitals were collected for 9 months from interviews, a time-motion study, observations, and reviews of bills. Charges for a follow-up visit were about 25% higher than Medicare's allowable charges, but differed threefold across practices. Physicians spent more than half their allocated patient care or supervision time in other activities and 14% of nursing time was used for direct patient care. Visits to second- and third-year residents cost one half of those to faculty. Faculty supervision of second- and third-year residents was limited; it was, on average, 2 minutes per follow-up visit. Despite these inefficiencies, bad debts, and educational costs, practices appeared to break even financially. We conclude it is financially feasible for university hospitals to provide primary care to disadvantaged populations.

Costs and Cost Analysis↗

Sufficiency of clinical literature on the appropriate uses of six medical and surgical procedures.

We reviewed the English-language clinical literature on carotid endarterectomy, cholecystectomy, upper gastrointestinal endoscopy, colonoscopy, coronary angiography and coronary artery bypass graft procedure to identify the appropriateness of using these procedures in 1981. Most of the 803 relevant articles and textbooks were published after 1975; about 10% of the 571 research studies were randomized, controlled trials, while two thirds were retrospective studies. Incomplete or contradictory information was available on the indications for and efficacy of using the procedures; almost no data were available on costs and use; data on complications failed to specify patients' symptoms or the relationship between complications and reasons for doing the procedure.

Books↗

Use of carotid endarterectomy in five California Veterans Administration medical centers.

Although carotid endarterectomy is a controversial and frequently performed surgical procedure, little is known about the clinical appropriateness of its use in actual practice. Are the majority of procedures performed for highly accepted clinical reasons? We studied the clinical appropriateness of 107 procedures performed on 95 patients in 1981 in five Veterans Administration teaching medical centers. Standards for judging appropriate use were based on the recommendations of a multidisciplinary panel of nine physicians. Fifty-five percent of the procedures studied were judged clearly appropriate, 32% equivocal, and 13% clearly inappropriate. The rate of serious operative complications was 5.6%. These results suggest that carotid endarterectomy is overutilized within at least some segments of the Veterans Administration population.

Age Factors↗

Variations in the use of medical and surgical services by the Medicare population.

We measured geographic differences in the use of medical and surgical services during 1981 by Medicare beneficiaries (age greater than or equal to 65) in 13 large areas of the United States. The average number of Medicare beneficiaries per site was 340,000. We found large and significant differences in the use of services provided by all medical and surgical specialties. Of 123 procedures studied, 67 showed at least threefold differences between sites with the highest and lowest rates of use. Use rates were not consistently high in one site, but rates for procedures used to diagnose and treat a specific disease varied together, as did alternative treatments for the same condition. These results cannot be explained by the actions of a small number of physicians. We do not know whether physicians in high-use areas performed too many procedures, whether physicians in low-use areas performed too few, or whether neither or both of these explanations are accurate. However, we do know that the differences are too large to ignore and that unless they are understood at a clinical level, uninformed policy decisions that have adverse effects on the health of the elderly may be made.

Aged↗

Setting standards of performance for program evaluations: the case of the teaching hospital general medicine group practice program.

Program evaluation is like research in its use of the scientific method. An important difference is that evaluations result in judgments of merit. What are the standards for making the judgments? Little attention has been paid to their selection and use. This article reports on how standards were set in an evaluation of the structure of fifteen of the nation's university hospitals who participated in the Teaching Hospital General Medicine Group Practice Program (sponsored by the Robert Wood Johnson Foundation). Many sources were used to select standards including a review of the literature, expert advice and actual data from two years of the programs's performance. Also, the standard-setting process was a participatory one in which all potentially competing views were provided with a forum for discussion. Finally, standards were set in advance of the collection of information, facilitating the selection of study designs and analysis techniques. Almost all project directors stated that the process helped them in program planning and gave them ideas for research and evaluation. Because standard-setting has mutual benefits, we recommend that it take place during program planning.

Evaluation Studies as Topic↗

Evaluation of ambulatory care training by graduates of internal medicine residencies.

In 1984, 154 physicians who had completed residencies in internal medicine at 15 major teaching hospitals in 1982 evaluated their residency training in ambulatory care. A majority of the physicians would have liked more experience in practical areas related to career planning and office management, more input from subspecialties such as orthopedics and dermatology, greater knowledge about the management of psychosocial problems, and more information about exercise and nutrition. Although many physicians also wanted more time devoted to several other topics, less than 20 percent recommended spending less time on 26 of the 27 topics being evaluated. Since these recommendations are similar to those reported in evaluation studies published over the past 25 years, it appears that training programs in internal medicine have not been successful in restructuring their curricula to meet many of the needs of practicing physicians.

Ambulatory Care↗

Leukocyte adherence inhibition assay in the diagnosis and follow-up of colorectal cancer patients.

Antitumor immune response to colorectal cancer extract was tested by the tube leukocyte adherence inhibition (LAI) assay. Of 70 colorectal cancer patients, 38 (54%) were LAI-positive. In contrast, 15 of 159 (9%) healthy individuals and 2 of 28 (7%) patients with nonmalignant diseases were positive. The LAI activity disappeared a few months after surgery and remained negative in patients with no evidence of disease as well as in patients with disseminated progressed disease. A change of LAI from negative to positive during the follow up period correlated in some cases with the recurrence of the disease, but was observed also in cases with no clinical evidence of disease.

Colonic Neoplasms↗

Diagnostic value of the computerized tube leukocyte adherence inhibition (LAI) assay for human colorectal, breast and lung cancers.

We have tested by the computerized tube leukocyte adherence inhibition (LAI) assay, 319, 100 and 342 patients and controls for the presence of antitumor immunity to colorectal, breast and lung cancers. The assay was standardized and its sensitivity increased by using, as a challenging antigen, spent medium of human carcinoma cell lines and by the addition of prostaglandin E2 (PGE2). By large, the sensitivity of the assay (after the addition of PGE2) was inversely related to tumor burden, namely, it was 82.7, 78.9, and 88.6% as compared to 57.1, 33.3, and 29.6% for the early and late stages of colorectal, breast and lung cancers, respectively. Calculating the frequency of disease in the population studied and in comparison with known frequencies of the same in the general population, the positive and negative predicting values (PVpos, PVneg) were obtained. Our results demonstrate that the LAI assay cannot be applied for mass screening since its low PVpos would impair its effectiveness. However, its application to a population at high risk for developing a particular malignancy or as a second-line modality to more conventional screening methods would increase its cost-effectiveness and favor its applicability.

Breast Neoplasms↗

Physician ratings of appropriate indications for six medical and surgical procedures.

We convened three panels of physicians to rate the appropriateness of a large number of indications for performing a total of six medical and surgical procedures. The panels followed a modified Delphi process. Panelists separately assigned initial ratings, then met in Santa Monica, California where they received reports showing their initial ratings and the distribution of the other panelists ratings. They discussed the indications and revised the indications lists, then individually assigned final ratings. There was generally better agreement on the final ratings than on the initial ratings. Based on reasonable criteria for agreement and disagreement, and excluding one outlying procedure, the panelists agreed on ratings for 42 to 56 per cent of the indications, and disagreed on 11 to 29 per cent.

Angiography↗

Organ specific neoantigens reactive in the leukocyte adherence inhibition assay: affinity purification of human colon carcinoma antigen and its cross-reactive protein using monoclonal antibodies.

A monoclonal antibody (mAb) was prepared against a semipurified preparation of an organ specific neoantigen (OSN) reactive in the leukocyte adherence inhibition (LAI) assay. The mAb (LC20.1) induces a positive LAI response when incubated with leukocytes of normal individuals in the presence of OSN derived from either human colon or lung carcinoma cell lines. Absorption of crude OSN preparations from these cell lines on immobilized LC20.1 mAb eliminates all the LAI reactive material suggesting that the mAb recognizes a common determinant on OSN from both colon and lung carcinomas. The LC20 mAb was used to affinity purify the colon cancer OSN as well as a cross-reactive normal protein from the urine of colon cancer patients and healthy donors, respectively. The colon cancer OSN and normal cross-reactive protein display an apparent molecular weight of 29,000, have a similar linear tryptic peptide map, and are indistinguishable by isoelectric focusing analysis. Regardless of the molecular similarity, only the colon cancer OSN preparation could induce a positive LAI when incubated with leukocytes of colon cancer patients. Seven additional anti-colon cancer OSN mAbs were prepared against purified material. These mAbs can be divided into three groups, each of which recognizes a distinct antigenic determinant that is shared by the colon cancer neoantigen and its cross-reactive normal protein.

Animals↗

Ketotifen, disodium cromoglycate, and verapamil inhibit leukotriene activity: determination by tube leukocyte adherence inhibition assay.

Peripheral blood leukocytes (PBL) from asthmatic individuals lose their former ability to adhere to glass when incubated with leukotriene C4 (LTC4). A modified leukotriene-induced leukocyte adherence inhibition (LAI) assay was therefore used to study the ability of anti-asthmatic drugs to abrogate such activity. Ketotifen, disodium cromoglycate, Verapamil, and dimethpyridene, all at concentrations of 2 X 10(-6) M, were co-cultured with 2 X 10(-7) M LTC4 and their effect on the LTC4-induced LAI determined. Verapamil, Ketotifen, and disodium cromoglycate all inhibited the LTC4 activity while the H1 antagonist, dimethpyridene, did not. These results suggest that the beneficial effect of Verapamil, Ketotifen, and disodium cromoglycate in bronchial asthma is probably as calcium antagonists that cause the inhibition of leukotriene activity.

Calcium↗

Antitumor immune response to colorectal cancer antigen detected by the leukocyte adherence inhibition test (LAI) in groups at high risk for colorectal cancer.

Colorectal cancer is the second leading cause of cancer death in western populations. As treatment outcome is highly correlated with stage at diagnosis, early detection is a very important task. Three high-risk groups for colorectal cancer (first-degree relatives of colorectal cancer patients; individuals with past history of colorectal neoplasms, polyps, or carcinoma; and patients with ulcerative colitis) were screened for colonic neoplasms. The study program included the leukocyte adherence inhibition test (LAI), a specific immune response test for colorectal cancer antigen; fiberoptic sigmoidoscopy or colonoscopy; and guaiac impregnated slide test. The main finding was the detection of 92 positive LAI tests out of 451 high-risk individuals tested (20%), compared to eight positive tests out of 194 (4.1%) in a control group. Fifty-six colonic neoplasms were found out of 344 (16%) colonoscopies performed, most of them adenomatous polyps and a few carcinomas. Our findings, compared with the expected 2-3% neoplasms in low-risk groups, would prove that the screenees were indeed at high risk. However, only 11/56 (19%) of the polyps identified were LAI positive. The number of polyps found among LAI positive individuals were, so far, 11/92 (11%). The guaiac impregnated slide test for occult blood in the stool was performed in 221 screenees. Of these only 10 were positive (4.5%) compared with the average of 1% positive tests in low-risk groups.

Antigens, Neoplasm↗

Cesium and cobalt transfer from soil to vegetation on permanent pastures.

The Cs transfer from soil into pasture vegetation was investigated by using a variation of experimental conditions: (I) 67 pots with 7 kg soil from 3 marshy and 1 sandy site in the lower Weser region in Northwest Germany are used in a greenhouse with 134Cs under 8 different experimental procedures for 2 harvests; (II) 3 undisturbed 50 kg lysimeters were observed for 137Cs and 60Co transfer under outdoor conditions for 4 harvests, depth profiles of the activity were determined afterwards; (III) the transfer of the atmospheric fallout 137Cs directly to the vegetation and from soil to vegetation after preventing its direct uptake by plastic covers was determined at 4 locations in the open pasture. The experiments resulted in higher Cs transfer in the case of podzolic soil and/or direct injection of Cs solution into the rooting zone of old permanent pasture vegetation while the Cs transfer was about 2-4 fold lower when the radioactive solution was applied to newly sown grass. Transfer often decreases with increasing age of Cs in the soil. In addition, statistical analysis of the widely scattered data did not show significant results for the influence of type of marsh, experimental procedure, soil factors with pH of (4.5-6.1), organic carbon, amount of added Cs (microquantity), exchangeable, K, and total Ca. Some figures are given for 60Co. The observed transfer factors, combined from all experiments appear lognormally distributed with median values 0.22 on podzolic and 0.09 on marshy soils (Bq/kg fresh plant per Bq/kg air dried soil).

Agriculture↗