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The article examines the cost effectiveness of initial management of dyspepsia. A randomized clinical trial was conducted that compared a prompt endoscopy strategy with a test and treat approach for the initial management of dyspepsia in adults. Effects of the intervention on dyspepsia symptoms were pooled using meta-analysis of individual patient data. Initial management with prompt endoscopy is slightly more effective compared with a test and treat approach for inducing resolution of symptoms.

Background: Only a small number of trials have directly addressed the management of patients with "uninvestigated" dyspepsia. The design of trials to determine cost effectiveness is more complex than efficacy trials, and can be enhanced by pre-trial modelling. Methods: A simulation model of 72 alternative management strategies for a dyspeptic patient was constructed. The model simulated the flow of individual patients with potential upper Gl disorders through potential investigations and therapies, including endoscopy, non-invasive testing for H pylori, acid suppression therapy, and H pylori eradication. Epidemiological data and meta-analyses were used to specify parameters within the model. The model was used to establish the important comparisons for future research and to establish likely effect sizes in terms of cost and efficacy. Sensitivity analysis explored potential effect modifiers and the MRC-CUBE study was designed and powered on the basis of the model. Results: Recent trials have supported some of the model's findings, in that only empiric acid suppression with either an antacid or a PPI, or H pylori "test and treat", followed by acid suppression were cost effective. Test and treat was more effective, but more costly than empiric acid suppression alone. Based on the model, the minimum effect size would be 7%, assuming a maximum willingness to pay For a patient free of dyspepsia for a year of 100, and a control event rate of 70%. 1940 patients would be required for an α of 0.05 and β 0.1. Conclusions: The MRC-CUBE trial is about to start recruitment in 60 practices, a large, multi-centre trial being justified on the basis of the model. As well as informing the selection of appropriate comparisons, pre-trial modelling enables cost effectiveness trials to be powered for cost as well as effectiveness outcomes. [ABSTRACT FROM AUTHOR]

Background: This review considers management strategies (combinations of initial investigation and empirical treatments) for dyspeptic patients. Dyspepsia was defined to include both epigastric pain and heartburn., Objectives: To determine the effectiveness, acceptability, and cost effectiveness of the following initial management strategies for patients presenting with dyspepsia (a) Initial pharmacological therapy (including endoscopy for treatment failures). (b) Early endoscopy. (c) Testing for Helicobacter pylori (H. pylori )and endoscope only those positive. (d) H. pylori eradication therapy with or without prior testing., Search Strategy: Trials were located through electronic searches and extensive contact with trialists., Selection Criteria: All randomised controlled trials of dyspeptic patients presenting in primary care., Data Collection and Analysis: Data were collected on dyspeptic symptoms, quality of life and use of resources. An individual patient data meta-analysis of health economic data was conducted, Main Results: Twenty-five papers reporting 27 comparisons were found. Trials comparing proton pump inhibitors (PPI) with antacids (three trials) and histamine H2-receptor antagonists (H2RAs) (three trials), early endoscopy with initial acid suppression (five trials), H. pylori test and endoscope versus usual management (three trials), H. pylori test and treat versus endoscopy (six trials), and test and treat versus acid suppression alone in H. pylori positive patients (four trials), were pooled. PPIs were significantly more effective than both H2RAs and antacids. Relative risks (RR) and 95% confidence intervals (CI) were; for PPI compared with antacid 0.72 (95% CI 0.64 to 0.80), PPI compared with H2RA 0.63 (95% CI 0.47 to 0.85). Results for other drug comparisons were either absent or inconclusive. Initial endoscopy was associated with a small reduction in the risk of recurrent dyspeptic symptoms compared with H. pylori test and treat (OR 0.75, 95% CI 0.58 to 0.96), but was not cost effective (mean additional cost of endoscopy US$401 (95% CI $328 to 474). Test and treat may be more effective than acid suppression alone (RR 0.59 95% CI 0.42 to 0.83)., Authors' Conclusions: Proton pump inhibitor drugs (PPIs) are effective in the treatment of dyspepsia in these trials which may not adequately exclude patients with gastro-oesophageal reflux disease (GORD). The relative efficacy of histamine H2-receptor antagonists (H2RAs) and PPIs is uncertain. Early investigation by endoscopy or H. pylori testing may benefit some patients with dyspepsia but is not cost effective as part of an overall management strategy.

Background: This review considers management strategies (combinations of initial investigation and empirical treatments) for dyspeptic patients. Dyspepsia was defined to include both epigastric pain and heartburn., Objectives: To determine the effectiveness, acceptability, and cost effectiveness of the following initial management strategies for patients presenting with dyspepsia: (a) Initial pharmacological therapy (including endoscopy for treatment failures). (b) Early endoscopy. (c) Testing for Helicobacter pylori (H. pylori )and endoscope only those positive. (d) H. pylori eradication therapy with or without prior testing., Search Strategy: Trials were located through electronic searches and extensive contact with trialists., Selection Criteria: All randomised controlled trials of dyspeptic patients presenting in primary care., Data Collection and Analysis: Data were collected on dyspeptic symptoms, quality of life and use of resources. An individual patient data meta-analysis of health economic data was conducted, Main Results: Twenty-five papers reporting 27 comparisons were found. Trials comparing proton pump inhibitors (PPI) with antacids (three trials) and histamine H2-receptor antagonists (H2RAs) (three trials), early endoscopy with initial acid suppression (five trials), H. pylori test and endoscope versus usual management (three trials), H. pylori test and treat versus endoscopy (six trials), and test and treat versus acid suppression alone in H. pylori positive patients (four trials), were pooled. PPIs were significantly more effective than both H2RAs and antacids. Relative risks (RR) and 95% confidence intervals (CI) were; for PPI compared with antacid 0.72 (95% CI 0.64 to 0.80), PPI compared with H2RA 0.63 (95% CI 0.47 to 0.85). Results for other drug comparisons were either absent or inconclusive. Initial endoscopy was associated with a small reduction in the risk of recurrent dyspeptic symptoms compared with H. pylori test and treat (OR 0.75, 95% CI 0.58 to 0.96), but was not cost effective (mean additional cost of endoscopy US$401 (95% CI $328 to 474). Test and treat may be more effective than acid suppression alone (RR 0.59 95% CI 0.42 to 0.83)., Authors' Conclusions: Proton pump inhibitor drugs (PPIs) are effective in the treatment of dyspepsia in these trials which may not adequately exclude patients with gastro-oesophageal reflux disease (GORD). The relative efficacy of histamine H2-receptor antagonists (H2RAs) and PPIs is uncertain. Early investigation by endoscopy or H. pylori testing may benefit some patients with dyspepsia but is not cost effective as part of an overall management strategy.

Background & Aims: Helicobacter pylori "test and treat" has been recommended for the management of young dyspeptic patients without alarm symptoms, and trials have suggested that it is as effective as endoscopy. However, none of these trials have had sufficient sample size to confirm that "test and treat" costs less or to detect small differences in effect. A collaborative group has prospectively registered trials comparing prompt endoscopy with a "test and treat" approach, with the aim of performing an individual patient data meta-analysis of both effect and resource utilization data., Methods: Researchers provided data for meta-analysis, pooling effects of interventions on individual dyspepsia symptoms. Standardized unit costs were applied to resource utilization, and net benefit was calculated at patient level. Effects, costs, and net benefit were then pooled at study level., Results: Five trials were identified, containing 1924 patients (946 endoscopy [mean age, 40 years], 978 "test and treat" [mean age, 41 years]). The relative risk (RR) of remaining symptomatic after 1 year was reduced with endoscopy compared with "test and treat" (RR = 0.95; 95% confidence interval [CI]: 0.92-0.99). "Test and treat" cost 389 dollars less per patient (95% CI: 275-502 dollars). Using the net benefit approach, at no realistic level of willingness to pay per patient symptom-free did prompt endoscopy become cost-effective., Conclusions: Prompt endoscopy confers a small benefit in terms of cure of dyspepsia but costs more than "test and treat" and is not a cost-effective strategy for the initial management of dyspepsia.

1. The effects of 2, 8 and 21 day oral treatment with the specific gamma-aminobutyric acid transaminase (GABA-T) inhibitors gamma-vinyl GABA (GVG) and ethanolamine O-sulphate (EOS) on brain GABA levels, GABA-T activity, and basal and stimulated GABA release from rat cross-chopped brain hippocampal slices was investigated. 2. Treatment with GABA-T inhibitors lead to a reduction in brain GABA-T activity by 65-80% compared with control values, with a concomitant increase in brain GABA content of 40-100%. 3. Basal hippocampal GABA release was increased to 250-450% of control levels following inhibition of GABA-T activity. No Ca2+ dependence was observed in either control or treated tissues. 4. GVG and EOS administration led to a significant elevation in the potassium stimulated release of GABA from cross-chopped hippocampal slices compared with that of controls. Although stimulated GABA release from control tissues was decreased in the presence of a low Ca2+ medium, GVG and EOS treatment abolished this Ca2+ dependency. 5. GABA compartmentalization, Na+ and Cl- coupled GABA uptake carriers and glial release may provide explanations for the loss of the Ca2+ dependency of stimulated GABA release observed following GVG and EOS treatment. 6. Administration of GABA-T inhibitors led to increases in both basal and stimulated hippocampal GABA release. However, it is not clear which is the most important factor in the anticonvulsant activity of these drugs, the increased GABA content 'leaking' out of neurones and glia leading to widespread inhibition, or the increase in stimulated GABA release which may occur following depolarization caused by an epileptic discharge.

The effects of chronic treatment with the specific, mechanism-based, irreversible inhibitors of 4-aminobutyrate aminotransferase (EC 2.6.1.19; GABA transaminase), ethanolamine O-sulphate (EOS), and 4-aminohexenoate [vigabatrin; gamma-vinyl-GABA (GVG)] on the extracellular concentrations of GABA in the hippocampus have been studied using in vivo microdialysis in conscious animals. Oral dosing [3 mg/ml of drinking water, giving doses of GVG of 194 +/- 38 mg/kg/day and of EOS of 303 +/- 42 mg/kg/day (mean +/- SD)] was followed by microdialysis at 2, 8, and 21 days. The basal outflow of GABA (in the range of approximately 1-2 pmol/30 microliters/30-min sample) after 2 and 8 days of treatment was not significantly different from that in control animals, but the 21-day treatment gave significant rises in the extracellular GABA concentration (up to approximately 6-8 pmol/30 microliters/30-min sample). Both inhibitors gave similar results. Depolarisation with 100 mM K+ gave large increases in GABA release in control (approximately 20-60 pmol/30 microliters/30-min sample) and treated animals. The 8- and 21-day-treated animals showed significant increases in the stimulated release compared with control animals (approximately 80-100 pmol/30 microliters/30-min sample). Excluding Ca2+ had no significant effect on either basal or stimulated release. The significant increases in K(+)-evoked release of GABA show that the increased intracellular pool of GABA is available for release, and this may be related to the anticonvulsant action of these compounds.

Post-mortem cerebral cortex from 15 demented patients was specially collected to minimise autolysis and two membrane fractions and one soluble fraction were quantitatively examined for the major species of beta-amyloid precursor protein (APP) of high apparent molecular mass (> or = 80 kDa) together with the major mRNA species encoding APP isoforms. The number of pyramidal neurones and astrocytes, putative biochemical indices of interneurones and pyramidal neurones, and choline acetyl transferase activity were also determined. Multiple regression analysis has been used to investigate intercorrelations of APP species with biochemical and morphometric measures, free of any effects of confounding demographic variables. Subjects with Alzheimer's disease showed a loss of cholinergic activity and D-aspartate uptake compared with patients with other causes of dementia. The major finding of the study is that measures of neurones rather than astrocytes most closely correlate with the concentration of APP. Pyramidal cell numbers were positively correlated with mRNA for APP695. APP in the soluble fraction showed a negative correlation with pyramidal cell numbers and cholinergic activity. These results indicate that neurones within the cerebral cortex are the major source of APP, and that secretion of APP is dependent upon cortical pyramidal neuronal activity and cholinergic activity.