Biomedical subjects

John McKay

Publications and source records attributed to John McKay.

8 recordsLinked to original sources

PubMed2006

Economic evaluation of a clinical protocol for diagnosing emergency patients with suspected pulmonary embolism.

BACKGROUND: The objective of this paper is to estimate the amount of cost-savings to the Australian health care system from implementing an evidence-based clinical protocol for diagnosing emergency patients with suspected pulmonary embolism (PE) at the Emergency department of a Victorian public hospital with 50,000 presentations in 2001-2002. METHODS: A cost-minimisation study used the data collected in a controlled clinical trial of a clinical protocol for diagnosing patients with suspected PE. The number and type of diagnostic tests in a historic cohort of 185 randomly selected patients, who presented to the emergency department with suspected PE during an eight month period prior to the clinical trial (January 2002-August 2002) were compared with the number and type of diagnostic tests in 745 patients, who presented to the emergency department with suspected PE from November 2002 to August 2003. Current Medicare fees per test were used as unit costs to calculate the mean aggregated cost of diagnostic investigation per patient in both study groups. A t-test was used to estimate the statistical significance of the difference in the cost of resources used for diagnosing PE in the control and in the intervention group. RESULTS: The trial demonstrated that diagnosing PE using an evidence-based clinical protocol was as effective as the existing clinical practice. The clinical protocol offers the advantage of reducing the use of diagnostic imaging, resulting in an average cost savings of at least $59.30 per patient. CONCLUSION: Extrapolating the observed cost-savings of $59.30 per patient to the whole of Australia could potentially result in annual savings between $3.1 million to $3.7 million.

Journal Article↗

PubMed2006

Efficacy of milk versus water to reduce interfering infra-cardiac activity in 99mTc-sestamibi myocardial perfusion scintigraphy.

OBJECTIVE: Interference from infra-cardiac radionuclide activity prevents accurate interpretation of true myocardial perfusion. The study aim was to compare the efficacy of milk versus water in reducing infra-cardiac activity in myocardial perfusion scintigraphy. METHODS: We prospectively randomized 198 patients undergoing stress-rest (99m)Tc-sestamibi SPECT with exercise or pharmacological stress to drink 300 ml of water or milk prior to imaging. A semi-quantitative grading of the relative intensity of infra-cardiac activity compared to the myocardial activity and a qualitative assessment of the effect on the overall interpretation was performed. RESULTS: For stress images, there was no infra-cardiac activity in 37.9%, less intense infra-cardiac activity in 40.8%, equal in 11.7% and greater than infra-cardiac activity in 9.7% with milk, compared with 20.0%, 49.5%, 20.0% and 10.5%, respectively, with water (P=0.038). For rest images, there was also less intense infra-cardiac activity with milk compared to water (P=0.014). However, no change in subsequent image interpretation was seen. CONCLUSION: Administration of milk resulted in a significant decrease in the intensity of infra-cardiac activity compared to water. However, this did not translate into an improvement in image interpretation.

Animals↗

PubMed2006

Variations in the ability of general medical practitioners to apply two methods of clinical audit: A five-year study of assessment by peer review.

INTRODUCTION: Clinical audit has a central role in the NHS clinical governance agenda and the professional appraisal of medical practitioners in the UK. However, concerns have been raised about the poor design and impact of clinical audit studies and the ability of practitioners to apply audit methods. One method of making informed judgements on audit performance is by peer review. In the west of Scotland a voluntary peer review model has been open to general practitioners since 1999, while general practice trainees are compelled to participate as part of summative assessment. The study aimed to compare the outcomes of peer review for two methods of audit undertaken by different professional and academic groups of doctors. METHODS: Participants submitted a criterion audit or significant event analysis in standard formats for review by two informed general practitioners (GPs) using appropriate instruments. Peer review outcome data and the professional status of doctors participating were generated by computer search. Differences in proportions of those gaining a satisfactory peer review for each group were calculated. RESULTS: Of 1002 criterion audit submissions, 552 (55%) were judged to be satisfactory. GP registrars were significantly more likely than GP trainers (P < 0.001) and other established GP groups (P < 0.001) to gain a satisfactory peer review. GPs in non-training practices were less likely to achieve a satisfactory review than registrars (P < 0.001) and colleagues in training practices (P < 0.001). Of 883 SEA submissions, 541 (65%) were judged as satisfactory, with all groups gaining a similar proportion of satisfactory assessments, although GP registrars may have outperformed non-training practice GPs (P = 0.05). CONCLUSION: A significant proportion of GPs may be unable to adequately apply audit methods, potentially raising serious questions about the effectiveness of clinical audit as a health care improvement policy in general medical practice.

Clinical Competence↗

PubMed2006

Natural genetic variation in whole-genome expression in Arabidopsis thaliana: the impact of physiological QTL introgression.

A long-standing and fundamental question in biology is how genes influence complex phenotypes. Combining near-isogenic line mapping with genome expression profiling offers a unique opportunity for exploring the functional relationship between genotype and phenotype and for generating candidate genes for future study. We used a whole-genome microarray produced with ink-jet technology to measure the relative expression level of over 21,500 genes from an Arabidopsis thaliana near-isogenic line (NIL) and its recurrent parent. The NIL material contained two introgressions (bottom of chromosome II and top of chromosome III) of the Cvi-1 ecotype in a Ler-2 ecotype genome background. Each introgression 'captures' a Cvi allele of a physiological quantitative trait loci (QTL) that our previous studies have shown increases transpiration and reduces water-use efficiency at the whole-plant level. We used a mixed model anova framework for assessing sources of expression variability and for evaluating statistical significance in our array experiment. We discovered 25 differentially expressed genes in the introgression at a false-discovery rate (FDR) cut-off of 0.20 and identified new candidate genes for both QTL regions. Several differentially expressed genes were confirmed with QRT-PCR (quantitative reverse transcription-polymerase chain reaction) assays. In contrast, we found no statistically significant differentially expressed genes outside of the QTL introgressions after controlling for multiple tests. We discuss these results in the context of candidate genes, cloning QTL, and phenotypic evolution.

Arabidopsis↗

PubMed2005

Reducing the use of diagnostic imaging in patients with suspected pulmonary embolism: validation of a risk assessment strategy.

OBJECTIVES: The aims of this study were to measure the: (i) effects of implementation of a new risk assessment strategy for patients with suspected pulmonary embolism (PE) on the use of imaging and D-dimer assay; (ii) negative predictive value for PE of a combination of low risk and negative D-dimer assay; and (iii) compliance of ED clinicians with the strategy. METHODS: A non-randomized clinical trial was conducted in the ED of a 720-bed teaching hospital between November 2002 and August 2003. Study subjects with suspected PE were compared with 191 randomly selected historical controls. The risk assessment strategy of Kline et al. was disseminated and implemented. RESULTS: The negative predictive value for PE was 99% (95% confidence interval [CI] = 97-100%) in 114 patients with low risk and negative D-dimer. There was a 21% absolute reduction in the rate of imaging following the implementation of the risk assessment strategy (56% vs 77%, P < 0.001). CONCLUSION: Low risk combined with a negative D-dimer result may allow exclusion of PE without imaging.

Anticoagulants↗

PubMed2004

Treatment of chronic prostatitis/chronic pelvic pain syndrome with tamsulosin: a randomized double blind trial.

PURPOSE: We compared the efficacy of tamsulosin with placebo for the treatment of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). MATERIALS AND METHODS: In a double blind phase II trial, 58 patients 55 years old or younger with moderate to severe CP/CPPS were randomized to receive 0.4 mg tamsulosin or placebo for 6 weeks. Patients were assessed on days -14 and -1 during a 2-week washout, and on days 15 and 45. The primary end point was the change from baseline in total National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) score on day 45. Secondary end points were the change from baseline in total NIH-CPSI score on day 15 and the change from baseline in pain, urinary symptoms and quality of life/impact domains of the NIH-CPSI on days 15 and 45. Analyses of responders were performed post hoc. RESULTS: On day 45 the treatment effect (difference between treatment groups in change from baseline) was -3.6 (p = 0.04) in favor of tamsulosin. The overall effect of tamsulosin was a function of the baseline total NIH-CPSI score. Treatment effect increased significantly as the baseline score increased (for total NIH-CPSI p <0.01). Tamsulosin efficacy was superior to placebo at the 75th percentile of baseline score for the total NIH-CPSI score (-8.3, p <0.01), the pain domain (-2.9, p = 0.02), the urinary symptoms domain (-2.3, p <0.01) and the impact/quality of life domain (-2.1, p = 0.02). The efficacy of tamsulosin increased with time (no significant treatment difference at 15 days) and tamsulosin was well tolerated. CONCLUSIONS: Tamsulosin was superior to placebo in providing symptomatic relief in men with CP/CPPS, particularly in those with more severe symptoms.

Adrenergic alpha-1 Receptor Antagonists↗

PubMed2004

Economic development and its influences and risks for nutrition, cuisine and health.

This paper reviews the evidence on some of the major trends in economic development at a global level and assess their influence on food, nutrition and health. Food and nutrition are themselves broad topics, and each is influenced by a myriad of local and international forces, making them both interesting and important, but also challenging in their complexity. It is especially difficult to deal with such a vast and complicated terrain in such a short paper, and one must inevitably deal only superficially with a number of complex areas. This paper will review a number of key forces for change in the global system, with a focus on the implications of each for food and nutrition. Each area is central to the experience of economic, social and political development, particularly in the period since 1945, and each is tied in various ways with that complex and interrelated set of changes that we call globalisation. Seven key factors will be explored: global population growth, leading to strong pressures on world availability of arable land and food; increasing integration in the global economy, as measured through such things as trade, financial flows and information exchanges, and with specific implications for the food industry and for trade in food products; growing gaps between rich and poor countries; similar increases in disparities between rich and poor segments within individual countries; the rapid growth of cities in the developing world, resulting in massive challenges for the food supply systems of many nations; the growth within some countries, for example in a number of Asian countries, of a "new middle class" with distinctive patterns of consumption; and, high levels of population movements between countries resulting in the creation of significant communities of immigrants in a number of nations. Examples will be drawn from the two regions familiar to the author, Asia and Sub-Saharan Africa, but with a particular emphasis on East Asia.

Asia↗

PubMed2003

Chronic cough.

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Adult↗