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Item Systematic review of the clinical effectiveness and cost-effectiveness of oesophageal Doppler monitoring in critically ill and high-risk surgical patients(National Institute for Health Research, 2009-01) Mowatt, Graham; Houston, G.; Hernández, Rodolfo Andrés; De Verteuil, Robyn; Fraser, Cynthia Mary; Cuthbertson, Brian; Vale, Luke David; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health SciencesObjectives: To assess the effectiveness and costeffectiveness of oesophageal Doppler monitoring (ODM) compared with conventional clinical assessment and other methods of monitoring cardiovascular function. Data sources: Electronic databases and relevant websites from 1990 to May 2007 were searched. Review methods: This review was based on a systematic review conducted by the US Agency for Healthcare Research and Quality (AHRQ), supplemented by evidence from any additional studies identified. Comparator interventions for effectiveness were standard care, pulmonary artery catheters (PACs), pulse contour analysis monitoring and lithium or thermodilution cardiac monitoring. Data were extracted on mortality, length of stay overall and in critical care, complications and quality of life. The economic assessment evaluated strategies involving ODM compared with standard care, PACs, pulse contour analysis monitoring and lithium or thermodilution cardiac monitoring. Results: The AHRQ report contained eight RCTs and was judged to be of high quality overall. Four comparisons were reported: ODM plus central venous pressure (CVP) monitoring plus conventional assessment vs CVP monitoring plus conventional assessment during surgery; ODM plus conventional assessment vs CVP monitoring plus conventional assessment during surgery; ODM plus conventional assessment vs conventional assessment during surgery; and ODM plus CVP monitoring plus conventional assessment vs CVP monitoring plus conventional assessment postoperatively. Five studies compared ODM plus CVP monitoring plus conventional assessment with CVP monitoring plus conventional assessment during surgery. There were fewer deaths [Peto odds ratio (OR) 0.13, 95% CI 0.02–0.96], fewer major complications (Peto OR 0.12, 95% CI 0.04–0.31), fewer total complications (fixed-effects OR 0.43, 95% CI 0.26–0.71) and shorter length of stay (pooled estimate not presented, 95% CI –2.21 to –0.57) in the ODM group. The results of the meta analysis of mortality should be treated with caution owing to the low number of events and low overall number of patients in the combined totals. Three studies compared ODM plus conventional assessment with conventional assessment during surgery. There was no evidence of a difference in mortality (fixed-effects OR 0.81, 95% CI 0.23–2.77). Length of hospital stay was shorter in all three studies in the ODM group. Two studies compared ODM plus CVP monitoring plus conventional assessment vs CVP monitoring plus conventional assessment in critically ill patients. The patient groups were quite different (cardiac surgery and major trauma) and neither study, nor a meta-analysis, showed a statistically significant difference in mortality (fixed-effects OR 0.84, 95% CI 0.41–1.70). Fewer patients in the ODM group experienced complications (OR 0.49, 95% CI 0.30–0.81) and both studies reported a statistically significant shorter median length of hospital stay in that group. No economic evaluations that met the inclusion criteria were identified from the existing literature so a series of balance sheets was constructed. The results show that ODM strategies are likely to be cost-effective. Conclusions: More formal economic evaluation would allow better use of the available data. All identified studies were conducted in unconscious patients. However, further research is needed to evaluate new ODM probes that may be tolerated by awake patients. Given the paucity of the existing economic evidence base, any further primary research should include an economic evaluation or should provide data suitable for use in an economic model.Item The clinical effectiveness and cost-effectiveness of screening for open angle glaucoma : a systematic review and economic evaluation(Gray Publishing, 2007-10) Burr, Jennifer Margaret; Mowatt, Graham; Hernández, Rodolfo Andrés; Siddiqui, Muhammad Ardul Rehman; Cook, Jonathan Alistair; Lourenco, Tania; Ramsay, Craig R; Vale, Luke David; Fraser, Cynthia Mary; Azuara-Blanco, Augusto; Deeks, J.; Cairns, J.; Wormald, R.; McPherson, S.; Rabindranath, K.; Grant, Adrian Maxwell; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health SciencesObjectives: To assess whether open angle glaucoma (OAG) screening meets the UK National Screening Committee criteria, to compare screening strategies with case finding, to estimate test parameters, to model estimates of cost and cost-effectiveness, and to identify areas for future research. Data sources: Major electronic databases were searched up to December 2005. Review methods: Screening strategies were developed by wide consultation. Markov submodels were developed to represent screening strategies. Parameter estimates were determined by systematic reviews of epidemiology, economic evaluations of screening, and effectiveness (test accuracy, screening and treatment). Tailored highly sensitive electronic searches were undertaken. Results: Most potential screening tests reviewed had an estimated specificity of 85% or higher. No test was clearly most accurate, with only a few, heterogeneous studies for each test. No randomised controlled trials (RCTs) of screening were identified. Based on two treatment RCTs, early treatment reduces the risk of progression. Extrapolating from this, and assuming accelerated progression with advancing disease severity, without treatment the mean time to blindness in at least one eye was approximately 23 years, compared to 35 years with treatment. Prevalence would have to be about 3–4% in 40 year olds with a screening interval of 10 years to approach costeffectiveness. It is predicted that screening might be cost-effective in a 50-year-old cohort at a prevalence of 4% with a 10-year screening interval. General population screening at any age, thus, appears not to be cost-effective. Selective screening of groups with higher prevalence (family history, black ethnicity) might be worthwhile, although this would only cover 6% of the population. Extension to include other at-risk cohorts (e.g. myopia and diabetes) would include 37% of the general population, but the prevalence is then too low for screening to be considered cost-effective. Screening using a test with initial automated classification followed by assessment by a specialised optometrist, for test positives, was more cost-effective than initial specialised optometric assessment. The cost-effectiveness of the screening programme was highly sensitive to the perspective on costs (NHS or societal). In the base-case model, the NHS costs of visual impairment were estimated as £669. If annual societal costs were £8800, then screening might be considered cost-effective for a 40-year-old cohort with 1% OAG prevalence assuming a willingness to pay of £30,000 per quality-adjusted life-year. Of lesser importance were changes to estimates of attendance for sight tests, incidence of OAG, rate of progression and utility values for each stage of OAG severity. Cost-effectiveness was not particularly sensitive to the accuracy of screening tests within the ranges observed. However, a highly specific test is required to reduce large numbers of false-positive referrals. The findings that population screening is unlikely to be cost-effective are based on an economic model whose parameter estimates have considerable uncertainty. In particular, if rate of progression and/or costs of visual impairment are higher than estimated then screening could be cost-effective. Conclusions: While population screening is not costeffective, the targeted screening of high-risk groups may be. Procedures for identifying those at risk, for quality assuring the programme, as well as adequate service provision for those screened positive would all be needed. Glaucoma detection can be improved by increasing attendance for eye examination, and improving the performance of current testing by either refining practice or adding in a technology-based first assessment, the latter being the more cost-effective option. This has implications for any future organisational changes in community eye-care services. Further research should aim to develop and provide quality data to populate the economic model, by conducting a feasibility study of interventions to improve detection, by obtaining further data on costs of blindness, risk of progression and health outcomes, and by conducting an RCT of interventions to improve the uptake of glaucoma testing.