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Biomedical subjects

J B Mitchell

Publications and source records attributed to J B Mitchell.

At least 361 records · Page 20Linked to original sources
PubMed1980

Large medicaid practices and medicaid mills.

There is growing concern that large Medicaid practices (LMPs) may be "Medicaid mills" in which low-quality care is provided. Based on survey data, this study sought to determine whether physicians who treat a disproportionate number of Medicaid patients are in fact operating mills. While practices with at least 30% Medicaid patients are a minority of all practices (15.8%), nearly 60% of all Medicaid patients receive care there. There is no evidence that LMPs can be characterized as Medicaid mills. Visit lengths are shorter in LMPs, but only by two minutes. Nor is there any widespread abuse of ancillary services, skimping on auxiliary staff, or excessive incomes. The LMP physicians, however, do tend to be older, to be trained in foreign medical schools, and to have fewer credentials, such as board certification.

Credentialing↗
PubMed1980

The usefulness of a predictive instrument to reduce inappropriate admissions to the coronary care unit.

A mathematical instrument was developed to supplement the diagnostic information available to physicians in the emergency room to improve physicians' diagnostic accuracy in managing patients with acute ischemic heart disease and thereby reduce inappropriate coronary care unit admissions. The instrument was empirically derived and is based on nine clinical, historical, and electrocardiographic predictive variables. Probabilities of acute ischemic heart disease generated by the instrument were given to the house staff in an emergency room during alternate months. Comparison of the control months (455 patients) with the experimental months (401 patients) showed the following: The overall diagnostic accuracy increased from 83% to 91% (P less than 0.005), the overdiagnostic accuracy increased from 51% to 33% (P less than 0.01), and the admission rate to the coronary care unit fell from 26% to 14% (P less than 0.001), while the inappropriate discharge rate from the emergency room did not change, 3% versus 3% (not significant).

Coronary Care Units↗
PubMed1980

Medicaid mills: fact or fiction.

Physician nonparticipation in Medicaid programs not only will restrict access of the poor to mainstream medicine but will also encourage the development of large Medicaid practices (LMPs). Policymakers have become increasingly concerned that these settings may be "Medicaid mills" in which low quality care is provided. Using HCFA survey data, this study examined the characteristics of LMPs, defined as practices in which at least 30 percent of the patients are eligible for Medicaid. Nearly 60 percent of all Medicaid patients treated in private practices are seen in these LMPs (14.5 percent of all practices). Most LMPs do not appear to be Medicaid mills. LMP physicians earn what other physicians make at best; often they earn less. Nor is there any widespread abuse of ancillary services, skimping on auxilliary staff, or excessive markups over costs, all characteristic of Medicaid mills. Visit lengths are shorter in LMPs, but only by a minute or two. A substantial "credentials gap" does exist, however; the Medicaid market is dominated by less qualified physicians. LMP physicians tend to be older, non-board certified, and graduates of foreign medical schools.

Clinical Competence↗
PubMed1979

Implications of alternative sampling strategies for emergency medical service evaluation.

Evaluations of emergency medical service (EMS) programs have been ambiguous, due in part, to problems of sample definition. Four different sampling strategies were studied: 1) all patients in cardiac arrest; 2) patients with a final diagnosis of myocardial infarction (MI); 3) patients with an emergency room diagnosis of "rule out MI"; and 4) patients identified by the ambulance team as a possible MI. Using a regional data base of all ambulance runs, we created study samples based on each of these strategies and measured the error that may be introduced as a result of sample selection. Bias was measured along three parameters of EMS system performance: 1) observed incidence of MI in the ambulance system; 2) condition recognition--the ability of the ambulance team to correctly identify acute cardiac patients; and 3) emergency room and hospital mortality rates. The emergency room diagnosis strategy systematically excludes all false-positives, while samples based on the ambulance team's assessment omit all false-negatives. The final diagnosis strategy yields significant underestimates of cardiac mortality. Samples restricted to cardiac arrests result in biased estimates of both the incidence of MI and the number of deaths.

Ambulances↗
PubMed1979

Visualization of the interphase chromosomes of Ornithogalum virens and Muntiacus muntjak.

A technique for visualizing "interphase chromosomes" was applied to nuclei of the angio-spermous plant, Ornithogalum virens (2 n = 6), and the male mammal, Muntiacus munjak (2 n = 7), in an attempt to correlate the numbers of "chromosomes" visible during interphase with the respective diploid chromosome numbers. The alterations in chromosome structure observed during G1, S, and G2 periods were comparable to those previously reported in Allium cepa and Chinese hamster (CHO line) cells [33], but for technical reasons it was only possible to make accurate counts of interphase chromosomes in the G1 nuclei of O. virens. In addition, from our observations of interphase chromosomes that were pulse-labelled with tritiated thymidine and a parallel study of premature chromosome condensation (PCC) using pulse-labelled M.muntjak cells, we conclude that, although chromatin decondensation may be required for DNA synthesis, extreme chromatin decondensation can occur in the absence of DNA synthesis. Generally a morphological description of alterations in chromatin during interphase only roughly parallels the G1, S, and G2 phases defined by autoradiography following incorporation of tritiated thymidine. We suggest that both methods are valid through different ways of describing interphase.

Animals↗
PubMed1978

Chromosome condensation and radiation-induced G2 arrest studied by the induction of premature chromosome condensation following cell fusion.

When mitotic and interphase cells are fused together, the chromosomes of the interphase cell sometimes condense prematurely. The phenomenon of premature chromosome condensation (PCC) was utilized in investigating the problem of whether the chromosomes of cells suffering a radiation-induced G2 delay are capable of condensation. Colcemide-arrested mitotic cells were fused with synchronized G2 cells, and with irradiated cells suffering a G2 delay. The frequency of PCC in mitotic X G2 binucleate cells was determined. This was compared to the PCC frequency in an unirradiated synchronized population rich in G2 cells after fusion with mitotic cells. Flash-labelling with 3HTdR and autoradiography allowed us to eliminate S-phase cells. The frequency of G2 PCCs was not significantly different for the irradiated G2-delayed or unirradiated cells. From these results we conclude that the chromosomes of cells suffering a G2 arrest are capable of condensation, although the involvement of the condensation process in radiation-induced G2 delay cannot be ruled out.

Cell Cycle↗
PubMed1978

Patient outcomes in alternative long-term care settings.

The purpose of this study was to compare health status outcomes in three alternative long-term care settings in the Veterans Administration : 1) home care; 2) community-based nursing home care; and 3) hospital-based nursing home care. Patients were measured on a behavioral index of health status, at two points in time: when transferred from the acute care hospital to one of the three treatment programs (pretest and three months later (posttest). Since patients could not be randomly distributed to programs, two methods were employed to control for potential sample selection bias: the choice of a nonequivalent control group design, and multivariate analytic techniques. First, within each program type, patients were randomly selected from both a hospital that offered only that program as a long-term care alternative and from a hospital that provided all three treatment settings. Second, multiple regression analysis was used to control for pretest differences among patients. Patients placed in the home care program displayed the greatest mean improvement in functional health status, holding all other variables constant. This treatment effect was not uniform, however; patients showed differential rates of improvement across the three programs, based upon both initial health status and prognosis.

Adult↗