Evaluating the impact of moving from discipline-based to integrated assessment

BACKGROUND: The move from discipline-based to problem-based learning (PBL) at Adelaide University in 2000 offered exciting opportunities to integrate the teaching and learning of the basic and clinical sciences for medical undergraduates. However, several cohorts of students still needed to progress through the first 3 years of the more traditional curriculum. Paradoxically, their readiness to function in the integrated learning and assessment environment of the last 3 years was assessed in 7 separate discipline-based examinations at the end of third year. When considerable examination-related stress was noted in the 1997 cohort and students petitioned formally for a reduced examination load, it was considered to be time for assessment to lead the way in integrating the disciplines. AIM: After introducing third year integrated written assessments in 1998, we aimed to develop an integrated practical examination (IPE) linking theory to practice, and evaluate its impact on staff and students. METHODS: After extensive staff collaboration, a structured objective multistation IPE was developed and administered in 1999 and 2000. Its utility was evaluated using a model proposed earlier. RESULTS: Assessment validity was maximised by an extensive item review process. Reliability, as measured by Cronbach's alpha, was 0.79 and 0.80 in 1999 and 2000, respectively. An independent evaluation yielded qualitative data on the examination's educational impact, cost and acceptability. CONCLUSIONS: Investing time in changing from discipline-based to integrated assessment, integrating theory and practice, resulted in gains in assessment reliability, validity and educational impact on both staff and students.     

Ventricular rate stabilization for the prevention of pause dependent ventricular tachyarrhythmias: results from a prospective study in 309 ICD recipients

Reviews of stored electrograms from ICDs revealed a 5-30% incidence of short-long-short intervals preceding the onset of recurrent ventricular tachyarrhythmias. Rate stabilization by dedicated antibradycardia pacing algorithms has, therefore, been suggested to prevent onset of pause dependent tachyarrhythmias. However, the clinical efficacy of this approach has not been studied systematically. In a prospective multicenter crossover study, patients were randomized to activation or deactivation of an implemented ventricular rate stabilization algorithm (VRS) after first implant of a dual chamber ICD. After 3 months, all patients were crossed over to the alternate programming. The rate of appropriate spontaneous VA episodes was compared between VRS On and VRS Off. Stored electrograms were reviewed for evaluation of the mode of onset of tachyarrhythmias. Overall efficacy analysis was based on 309 patients enrolled in the study. Forty percent (124/309) of the patients experienced 4,973 VA episodes. Based on an intention-to-treat analysis, VRS Off and On arrhythmia incidence was 10.2 and 6.6 normalized to 3 months, respectively (risk reduction 35%; P = 0.18) On an on-treatment basis, a reduction from 9.0 episodes to 8.1 episodes (10% risk reduction, P = 0.24) was seen. In an extended Cox model adjusting for confounding variables, the relative risk for recurrent episodes was 0.92 during VRS On compared to Off (95% CI: 0.58-1.48; P = 0.74). During VRS Off, pause dependent onset was documented in only 36 (8%) of 427 visually analyzed episodes. There was no significant reduction in the incidence of recurrent ventricular tachyarrhythmias with VRS On compared to the Off programming in this prospective study.     

Guar gum reduces postprandial hypotension in older people

OBJECTIVE: To determine whether slowing of gastric emptying and glucose absorption with guar gum would reduce the fall in blood pressure after an oral glucose load in older subjects. DESIGN: A randomized, experimental, cross-over study. SETTING: Department of Nuclear Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia. PARTICIPANTS: Ten healthy subjects, age 67 to 78. MEASUREMENTS: Simultaneous measurements of gastric emptying, blood pressure, blood glucose, serum insulin, and oral glucose absorption (3-O-methyl-D-glucose [3-OMG]) on two occasions after ingestion of 300 mL water containing 50 g glucose and 30 mL lemon juice, 3 g 3-OMG labeled with 99mTc-sulphur colloid; with or without 9 g guar gum. Blood pressure and gastric emptying were monitored for 180 minutes. RESULTS: The magnitude of the falls in systolic (P = .02), diastolic (P < .05), and mean arterial (P = .05) blood pressure were less, and gastric emptying slower (P < .05), after guar. Blood glucose, insulin, and 3-OMG concentrations were reduced (P < .001 for all) by guar. 3-OMG concentrations were inversely related to the intragastric retention of glucose (r = -0.72, P = .02) and blood pressure was inversely related to 3-OMG (r = -0.64, P < .05) after the drink without guar. The blood glucose concentration was related to 3-OMG (r > 0.64, P < .05). CONCLUSION: Guar gum reduces the magnitude of the fall in blood pressure after oral glucose. Slowing of gastric emptying and glucose absorption may represent a novel approach to the treatment of postprandial hypotension.     

Chronic heart failure in Australian general practice. The Cardiac Awareness Survey and Evaluation (CASE) Study

OBJECTIVES: To investigate the frequency and general practitioner awareness of patients with chronic heart failure (CHF), and to evaluate a cardiac algorithm and document cardiac investigations performed in establishing this diagnosis. DESIGN AND SETTING: Between March and August 1998, consecutive patients aged 60 years and older presenting to their GP were assessed. In patients previously diagnosed with CHF, aetiology and diagnostic assessments were documented. In patients with suspected CHF (by a standardised algorithm, based on World Health Organization guidelines), further investigations and GP diagnosis were recorded. PATIENTS: 80 consecutive patients were assessed by each of 341 GPs throughout Australia, reflecting the Australian metropolitan/rural population mix of 1996. This provided a total of 22060 evaluable patients. MAIN OUTCOME MEASURES: Estimated numbers of patients with CHF in general practice (previously and newly diagnosed); major aetiological factors; use of ancillary diagnostic tests; drugs prescribed. RESULTS: CHF was diagnosed in 2905 of 22060 patients (13.2%) (2485 previously diagnosed and 420 newly diagnosed). Major aetiological factors were ischaemic heart disease and hypertension. Echocardiography had been performed in 64% of previously diagnosed patients, but was performed in only 22% of possible CHF patients. Angiotensin-converting enzyme (ACE) inhibitors were prescribed in 58.1% of patients with CHF. Patients with evidence of left ventricular dysfunction were more likely to have received ACE inhibitors. CONCLUSIONS: CHF appears to be very common in the elderly, based on GP diagnosis of the condition. Of 100 patients aged 60 years and over presenting to their GP, two new cases of CHF will be detected using a simple clinical algorithm in conjunction with appropriate diagnostic tests. ACE inhibitors appear to be underutilised.     

The coastal environment and human health: microbial indicators,pathogens, sentinels and reservoirs

Innovative research relating oceans and human health is advancing our understanding of disease-causing organisms in coastal ecosystems. Novel techniques are elucidating the loading, transport and fate of pathogens in coastal ecosystems, and identifying sources of contamination. This research is facilitating improved risk assessments for seafood consumers and those who use the oceans for recreation. A number of challenges still remain and define future directions of research and public policy. Sample processing and molecular detection techniques need to be advanced to allow rapid and specific identification of microbes of public health concern from complex environmental samples. Water quality standards need to be updated to more accurately reflect health risks and to provide managers with improved tools for decision-making. Greater discrimination of virulent versus harmless microbes is needed to identify environmental reservoirs of pathogens and factors leading to human infections. Investigations must include examination of microbial community dynamics that may be important from a human health perspective. Further research is needed to evaluate the ecology of non-enteric water-transmitted diseases. Sentinels should also be established and monitored, providing early warning of dangers to ecosystem health. Taken together, this effort will provide more reliable information about public health risks associated with beaches and seafood consumption, and how human activities can affect their exposure to disease-causing organisms from the oceans.     

The pharyngeal effect of partial nasal obstruction.

The case histroy and cinematoradiographic findings of a baby with partial nasal obstruction are presented. This infant's restriction to air entry at the nose led to severe airway obstruction during inspiration by a forward movement of the posterior pharyngeal wall and backward movement of the tongue and lower jaw. At the height of inspiration, there was total airway occlusion in the pharynx. These events can be explained by the pressure drop that takes place behind a restriction if air is sucked through it forcibly from an area of atmospheric pressure. Studies of postpalatal pressures in adults and infants demonstrate such a drop in pressure during nasal breathing if the nose is partly obstructed. If the adult or infant is able to respond to the diminished nasal airway by mouth breathing, there is no postpalatal pressure drop. It is suggested that partial nasal obstruction in a sleeping obligatory nasal-breathing infant could result in a sucking back of the tongue over the larynx in this "cafe coronary" type of situation. This could be the mechanism of the obstructive type of apnea recorded by Steinschneider, and of the asphyxial type of death that is suggested by autopsies on some "cot death" victims. This hypothesis is consistent with the frequency of infection of rhinitis and pharyngitis in victims of sudden infant death syndrome and with the seasonal incidence. Prevention of this obstructive type of apnea would depend on the recognition of infants showing inspiratory and expiratory changes in pharyngeal airway size as can be seen externally by the movements in the carotid triangle of the neck and confirmed by roentgenography or cinematoradiography.