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Biomedical subjects

J Michaels

Publications and source records attributed to J Michaels.

At least 19 recordsLinked to original sources
PubMed2001

Outbreak of Serratia marcescens infection in a neonatal intensive care unit.

We report an outbreak of Serratia marcescens infection in the neonatal intensive care unit of a community hospital. The outbreak involved eight neonates, (five infected and three colonized), one of whom died. Pulsed-field gel electrophoresis confirmed that all isolates were identical strains. Cohorting and isolation of the infected neonates helped to control the outbreak. No environmental source of infection was found.

Cross Infection↗
PubMed2001

Vascular patients' preferences for local treatment: an application of conjoint analysis.

OBJECTIVES: To investigate whether and to what extent vascular patients are willing to trade expected health outcomes for improvements in non-health benefits, such as the availability of local services, in the provision of peripheral vascular surgery. METHODS: Conjoint analysis was used to elicit patient preferences via a mailed questionnaire. Respondents were asked to consider pairwise descriptions of vascular services described in terms of a number of key attributes and asked to indicate which scenario description they preferred. Multivariate regression analysis was used to estimate the relative importance of the attributes to respondents. RESULTS: Of the 339 patients invited to participate, 161 (47%) returned a completed questionnaire, although 36 (11%) were found to be internally inconsistent and could not be used, leaving 125 (36%) for analysis. An unexpected problem arose with respect to the design of the conjoint analysis questionnaire. Specifically, three of the attributes in the regression model were found to be collinear. The source of this problem, how it was overcome and how it can be avoided in future studies is discussed. The results of the regression analysis indicated that the patients who responded had a preference for local treatment to the extent that they were willing to incur increased risks of perioperative mortality and amputation to receive treatment at their local hospital. These results are discussed in connection with those from a different study which elicited patient preferences for local treatment using a standard gamble technique. CONCLUSIONS: Policy-makers, when considering the potential benefits of regionalising health care, should seek to elicit the preferences of those patients who will be affected by the reorganisation.

Community Health Services↗
PubMed2000

Is there a positive volume-outcome relationship in peripheral vascular surgery? Results of a systematic review.

OBJECTIVES: to examine the evidence for the existence, or otherwise, of a positive volume-outcome relationship in the area of peripheral vascular surgery. DESIGN: systematic overview of prospective or retrospective volume-outcome studies. DATA SOURCES: seven bibliographic databases were searched for English-language articles published between 1986 and 1998. STUDY SELECTION: thirty-six articles published in peer-reviewed journals; excluding editorials, letters or abstracts; and addressing volume and outcome in peripheral vascular surgery. Criteria were applied and agreed by consensus between two of the authors. DATA EXTRACTION: the articles identified were independently assessed by two of the authors. Studies were categorised into three distinct areas - carotid endarterectomy- (17 studies), abdominal aortic aneurysm repair (16 studies) and other vascular interventions (four studies). Within each category studies were further classified according to full adjustment, partial adjustment or no adjustment for case mix. Where discrepancies arose, decisions were referred to a third author for arbitration. DATA SYNTHESIS: findings for carotid endarterectomy identified a positive volume-outcome relationship for both mortality and stroke at the physician level. There was less support for a positive relationship for mortality at the hospital level, and no evidence of benefits for stroke in higher volume hospitals. If only studies making a full adjustment for case mix are included, there is no clear support from statistically significant evidence for or against a positive volume-outcome relationship. For repair of unruptured abdominal aortic aneurysms there is evidence of a positive volume-outcome relationship at both the physician and hospital level, with evidence being particularly strong at the level of the hospital. For ruptured aneurysms the evidence is suggestive of there not being a positive volume-outcome relationship at the hospital level, while for physicians the evidence is more balanced with no clear support either way. For other vascular interventions there were insufficient studies (n=4) from which to draw meaningful conclusions. CONCLUSIONS: our results show that evidence of a relationship between volume and outcome in peripheral vascular surgery may be attributable to factors such as lack of adjustment for case-mix, different definitions of volume and poor quality of studies, especially those of retrospective design. Future studies should address these deficiencies by making full adjustment for case mix and by being prospective in design.

Aortic Aneurysm, Abdominal↗
PubMed1999

Costing vascular surgery: A review of current reporting practice.

OBJECTIVE: The objective of this study was to assess the level of reporting in economic studies in the area of peripheral vascular disease. Adequate reporting of data is necessary to judge the quality of economic studies by means of critical appraisal criteria. METHODS: A systematic review of the journal literature between 1986 and the first half of 1997 was undertaken. Studies that have attempted to estimate the resource consequences of one or more vascular procedure were the focus of the review. The extent of reporting in each study was assessed by using published guidelines. RESULTS: The review identified 30 articles from nine different countries for inclusion in the study. Of these, more than half were published in the last 2(1/2) years of the search period, indicating a recent and rapid growth in economic studies in this area. When subjected to the reporting guidelines, the studies performed rather poorly overall. CONCLUSIONS: Although the vascular studies can be criticized for inadequate reporting of economic data, it appears from the limited evidence from elsewhere that inadequate reporting is a problem in other clinical areas. In view of the importance of reporting to the ability to critically assess studies-and thus separate the "good" from the "bad"-there is a need for reporting to improve future published studies.

Costs and Cost Analysis↗
PubMed1996

A cost-utility analysis of laser-assisted angioplasty for peripheral arterial occlusions.

Despite the perception of many people that lasers represent the cutting edge of high-technology medicine, this form of medical technology has been subject to relatively little rigorous evaluation. This dearth of research relates particularly to economic evaluation, where there have been few attempts to justify the high cost of laser equipment. This paper details an economic evaluation of the use of laser technology as a secondary adjunct to angioplasty to treat peripheral arterial occlusions. Using data from a range of sources, including a published randomized trial, a cost-utility model is developed to estimate the costs and benefits of the laser, relative to standard angioplasty. The best available data indicate a cost-effective role for the laser, but important areas of uncertainty exist, including the laser's secondary recanalization rate, which has been estimated on the basis of limited numbers of patients. This uncertainty suggests that further research is required before widespread diffusion of the laser for use in this clinical context.

Adult↗
PubMed1995

State laws on tobacco control--United States, 1995.

PROBLEM/CONDITION: State laws on smoke-free indoor air, youth access to tobacco products, advertising of tobacco products, and excise taxes on tobacco products are summarized. REPORTING PERIOD COVERED: Legislation effective through June 30, 1995. DESCRIPTION OF SYSTEM: CDC and the National Cancer Institute (NCI) identified state laws addressing tobacco control by using LEXIS, which is an on-line legal research data base, and NCI's State Cancer Legislative Database (SCLD), which is a data base of legislation. CDC and NCI conducted detailed analyses of the content of the laws to identify specific provisions. RESULTS: CDC and NCI identified 1,238 state laws that address tobacco-control-related issues. Most laws either enact restrictions or strengthen current legislation that restricts tobacco use, sales to minors, or advertising; however, some laws preempt stronger measures by local ordinances. At the state level, forty-six states and Washington, DC require smoke-free indoor air to some degree or in some public places. All states prohibit the sale and distribution of tobacco products to minors, but only nine states restrict advertising of tobacco products. All states tax cigarettes (average excise tax is 31.5 cents per pack); 42 states also tax chewing tobacco and snuff. INTERPRETATION: State laws addressing tobacco control vary in relation to restrictiveness, enforcement and penalties, preemptions, and exceptions. ACTIONS TAKEN: The tables summarizing these laws are available through CDC's State Tobacco Activities Tracking and Evaluation (STATE) system and through NCI's SCLD. This information can be used by policy makers at the state and local levels to plan and implement initiatives on youth access to tobacco products and on the use, promotion, advertising, and taxation of tobacco products.

Advertising↗
PubMed1995

Community based heroin addicts who turn to experimental treatment rather than conventional care.

In this paper we report on a community based sample of heroin addicts not in addiction treatment who responded to the offer of experimental treatment (buprenorphine) for heroin addition. Comparison to a sample of methadone maintenance clients from the same geographic area reveals that on average the community sample began heroin use later, attained a higher level of education, and were most likely to have had a significant cohabitation relationship. The methadone maintenance sample, on the other hand, reported significantly greater regular use of drugs of abuse other than heroin. Each group may represent a different subgroup drawn from the heterogeneous heroin-addicted population. Implications for improved recruitment into treatment and enhanced treatment design are drawn from these findings.

Adult↗
PubMed1994

Overexpression of nef as a marker for restricted HIV-1 infection of astrocytes in postmortem pediatric central nervous tissues.

In previous studies, using polymerase chain reaction amplification of HIV-1 genes directly from pathologic tissues of children who died with AIDS encephalopathy, we showed that the reading frame of the HIV-1 regulatory nef gene is open, suggesting that the nef protein was expressed. We now show, using immunocytochemistry and in situ hybridization with nef-specific probes in postmortem pediatric CNS tissues, that nef mRNA and protein are present in up to 20% of astrocytes in tissue sections selected for extensive histopathology. By contrast, HIV-1 structural proteins such as gag and their coding mRNAs are present in multinucleated giant cells that harbor productive infection and are the hallmark of HIV-1 infection in the CNS. These findings are consistent with the nonproductive infection of glial cells observed in vitro, and imply that HIV-1 infection of astrocytes is restricted to early regulatory gene products, of which nef is the best target as it is expressed at high levels and is membrane-anchored. In developing central nervous tissues of children, restricted and latent HIV-1 infection of astrocytes may be extensive and contribute significantly to HIV-1 neuropathogenesis.

Aged↗
PubMed1993

Glomerulonephritis in rheumatoid arthritis.

We present data on 10 patients with RA who developed glomerulonephritis which was not related to gold or penicillamine therapy. Although two of these patients had received gold this had been discontinued 13 and 18 yr before the diagnosis of glomerulonephritis. Seven patients presented with nephrotic syndrome and three with proteinuria and microscopic haematuria. Renal histology showed a membranous nephropathy (five patients), mesangial IgA nephropathy (two patients), focal segmental necrotizing glomerulonephritis (two patients) and focal segmental glomerulosclerosis (one patient).

Adult↗
PubMed1993

Airway secretion clearance by mechanical exsufflation for post-poliomyelitis ventilator-assisted individuals.

Pulmonary complications from impaired airway secretion clearance mechanisms are major causes of morbidity and mortality for post-poliomyelitis individuals. The purpose of this study was to review the long-term use of manually assisted coughing and mechanical insufflation-exsufflation (MI-E) by post-poliomyelitis ventilator-assisted individuals (PVAIs) and to compare the peak cough expiratory flows (PCEF) created during unassisted and assisted coughing. Twenty-four PVAIs who have used noninvasive methods of ventilatory support for an average of 27 years, relied on methods of manually assisted coughing and/or MI-E without complications during intercurrent respiratory tract infections (RTIs). Nine of the 24 individuals were studied for PCEF. They had a mean forced vital capacity (FVC) of 0.54 +/- 0.47L and a mean maximum insufflation capacity achieved by air stacking of ventilator insufflations and glossopharyngeal breathing of 1.7L. The PCEF were as follows: unassisted, 1.78 +/- 1.16L/sec; following a maximum assisted insufflation, 3.75 +/- 0.73L/sec; with manual assistance by abdominal compression following a maximum assisted insufflation, 4.64 +/- 1.42L/sec; and with MI-E, 6.97 +/- 0.89L/sec. We conclude that manually assisted coughing and MI-E are effective and safe methods of airway secretion clearance for PVAIs with impaired expiratory muscle function who would otherwise be managed by endotracheal suctioning. Severely decreased maximum insufflation capacity but not vital capacity indicate need for a tracheostomy.

Aged↗
PubMed1993

Breast disease and the general surgeon. II. Effect of audit on the referral of patients with breast problems.

OBJECTIVES: To determine the number of patients with breast problems referred to general surgical clinics in a district general hospital and to assess the effect of changes implemented following the previous study on waiting time, investigations performed, and management of the patients. DESIGN: Two prospective outpatient audits with patient details recorded on questionnaires by the medical staff. SETTING: The general surgical outpatient clinics of a single general surgical firm at Newbury District Hospital, Berkshire. PATIENTS: Those patients attending the above clinics during two 3-month periods, 1 October to 31 December 1989 (Study 1), and 16 April to 19 July 1990 (Study 2). RESULTS: Of new referrals, 25% were for a breast problem. The waiting time fell from a median of 22 days in Study 1 to 10 days in Study 2. There was no significant difference between the studies for the proportion of each type of investigation performed. Between 80% and 85% of new patients did not need admission for an operation; however, of those operations performed, 65% were for carcinoma. The number of patients diagnosed as having carcinoma was the same in the two studies. CONCLUSIONS: That 25% of new, and up to 40% of follow-up patients seen in a general surgical clinic have breast problems. Many patients do not regard their symptoms as worrying and will not attend early clinic appointments even if these are offered. Writing to patients and general practitioners with the results of investigations ensures quicker receipt of the diagnosis and treatment plan, and reduces follow-up attendance. Only 15-20% of new patients need admission for an operation, and carcinoma is found in only 13-17%. Open access to the clinics does not result in general practitioners referring patients unnecessarily with breast problems.

Appointments and Schedules↗