Browsing by Author "Fraser, Cynthia Mary"

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64-slice computed tomography angiography in the diagnosis and assessment of coronary artery disease : systematic review and meta-analysis
(BMJ, 2008) Mowatt, Graham; Cook, Jonathan Alistair; Hillis, Graham Scott; Walker, Shonagh Mary; Fraser, Cynthia Mary; Jia, Xueli; Waugh, Norman Robert; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
Objective To assess whether 64-slice computed tomography (CT) angiography might replace some coronary angiography (CA) for diagnosis and assessment of coronary artery disease (CAD). Methods We searched electronic databases, conference proceedings and scanned reference lists of included studies. Eligible studies compared 64-slice CT with a reference standard of CA in adults with suspected/known CAD, reporting sensitivity and specificity or true and false positives and negatives. Data were pooled using the hierarchical summary receiver operating characteristic model. Results Forty studies were included; 28 provided sufficient data for inclusion in the meta-analyses, all using a cutoff of ≥ 50% stenosis to define significant CAD. In patient-based detection (n=1286) 64-slice CT pooled sensitivity was 99% (95% credible interval (CrI) 97 to 99%), specificity 89% (95% CrI 83 to 94%), median positive predictive value (PPV) across studies 93% (range 64 to 100%) and negative predictive value (NPV) 100% (range 86 to 100%). In segment-based detection (n=14,199) 64-slice CT pooled sensitivity was 90% (95% CrI 85 to 94%), specificity 97% (95% CrI 95 to 98%), median positive predictive value (PPV) across studies 76% (range 44 to 93%) and negative predictive value (NPV) 99% (range 95 to 100%). Conclusions 64-slice CT is highly sensitive for patient-based detection of CAD and has high NPV. An ability to rule out significant CAD means that it may have a role in the assessment of chest pain, particularly when the diagnosis remains uncertain despite clinical evaluation and simple non-invasive testing.
Alternative approaches to endoscopic ablation for benign enlargement of the prostate : a systematic review of randomised controlled trials
(BMJ, 2008) Lourenco, Tania; Pickard, Robert; Vale, Luke David; Grant, Adrian Maxwell; Fraser, Cynthia Mary; MacLennan, Graeme Stewart; N'Dow, James Michael Olu; Benign Prostatic Enlargement Team; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
Objective To compare the effectiveness and risk profile of newer methods for endoscopic ablation of the prostate against the current standard of transurethral resection. Design Systematic review and meta-analysis. Data sources Electronic and paper records in subject area up to March 2006. Review methods We searched for randomised controlled trials of endoscopic ablative interventions that included transurethral resection of prostate as one of the treatment arms. Two reviewers independently extracted data and assessed quality. Meta-analyses of prespecified outcomes were done using fixed and random effects models and reported using relative risk or weighted mean difference. Results We identified 45 randomised controlled trials meeting the inclusion criteria and reporting on 3970 participants. The reports were of moderate to poor quality, with small sample sizes. None of the newer technologies resulted in significantly greater improvement in symptoms than transurethral resection at 12 months, although a trend suggested a better outcome with holmium laser enucleation (random effects weighted mean difference -0.82, 95% confidence interval 1.76 to 0.12) and worse outcome with laser vaporisation (1.49, -0.40 to 3.39). Improvements in secondary measures, such as peak urine flow rate, were consistent with change in symptoms. Blood transfusion rates were higher for transurethral resection than for the newer methods (4.8% v 0.7%) and men undergoing laser vaporisation or diathermy vaporisation were more likely to experience urinary retention (6.7% v 2.3% and 3.6% v 1.1%). Hospital stay was up to one day shorter for the newer technologies. Conclusions Although men undergoing more modern methods of removing benign prostatic enlargement have similar outcomes to standard transurethral resection of prostate along with fewer requirements for blood transfusion and shorter hospital stay, the quality of current evidence is poor. The lack of any clearly more effective procedure suggests that transurethral resection should remain the standard approach.
The clinical and cost-effectiveness of open mesh repairs in adults presenting with a clinically diagnosed unilateral, primary inguinal hernia who are operated in an elective setting : systematic review and economic evaluation
(2015-11) Sharma, Pawana; Boyers, Dwayne; Scott, Neil William; Hernandez, Rodolfo Andres; Fraser, Cynthia Mary; Cruickshank, Moira; Ahmed, Irfan; Ramsay, Craig Robert; Brazzelli, Miriam Giovanna; University of Aberdeen.Aberdeen Centre for Evaluation; University of Aberdeen.Other Applied Health Sciences; University of Aberdeen.Health Economics Research Unit; University of Aberdeen.Institute of Applied Health Sciences; University of Aberdeen.Medical Statistics; University of Aberdeen.Aberdeen Health Psychology Group; University of Aberdeen.Applied Medicine
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 Sciences
Objectives: 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.
The clinical effectiveness of transurethral incision of the prostate : a systematic review of randomised controlled trials
(2010-02) Lourenco, Tania; Shaw, Matthew; Fraser, Cynthia Mary; MacLennan, Graeme Stewart; N'Dow, James Michael Olu; Pickard, Robert; University of Aberdeen.Other Applied Health Sciences; University of Aberdeen.Academic Urology Unit; University of Aberdeen.Institute of Applied Health Sciences
Efficacy and safety of using mesh or grafts in surgery for anterior and/or posterior vaginal wall prolapse: systematic review and meta-analysis.
(Elsevier Science, 2008) Jia, Xueli; Glazener, Cathryn Margaret Anne; Mowatt, Graham; MacLennan, Graeme Stewart; Fraser, Cynthia Mary; Bain, Christine; Burr, Jennifer Margaret
Background The efficacy and safety of mesh/graft in surgery for anterior or posterior pelvic organ prolapse is uncertain. Objectives To systematically review the efficacy and safety of mesh/graft for anterior or posterior vaginal wall prolapse surgery. Search strategy Electronic databases and conference proceedings were searched, experts and manufacturers contacted and reference lists of retrieved papers scanned. Selection criteria Randomised controlled trials (RCTs), non-randomised comparative studies, registries, case series involving at least 50 women, and RCTs published as conference abstracts from 2005 onwards. Data collection and analysis One reviewer screened titles/abstracts, undertook data extraction, and assessed study quality. Data analysis was conducted for three subgroups: anterior, posterior, and anterior and/or posterior repair (not reported separately). Results Forty-nine studies involving 4569 women treated with mesh/graft were included. Study quality was generally high. Median follow up was 13 months (range 1 to 51). In anterior repair, there was short-term evidence that mesh/graft (any type) significantly reduced objective prolapse recurrence rates compared with no mesh/graft (relative risk 0.48, 95% CI 0.32-0.72). Non-absorbable synthetic mesh had a significantly lower objective prolapse recurrence rate (8.8%, 48/548) than absorbable synthetic mesh (23.1%, 63/273) and biological graft (17.9%, 186/1041), but a higher erosion rate (10.2%, 68/666) than synthetic mesh (0.7%, 1/147) and biological graft (6.0%, 35/581). There was insufficient information to compare any of the other outcomes regardless of prolapse type. Conclusion Evidence for most outcomes was too sparse to provide meaningful conclusions. Rigorous long-term RCTs are required to determine the comparative efficacy of using mesh/graft.
Eltrombopag for the treatment of chronic idiopathic (immune) thrombocytopenic purpura : A Single Technology Appraisal
(NIHR Health Technology Assessment programme, 2008-12) Boyers, Dwayne; Jia, Xueli; Crowther, M; Jenkinson, David James; Fraser, Cynthia Mary; Mowatt, Graham; University of Aberdeen.Other Applied Health Sciences
Lens Extraction for Primary Angle Closure Glaucoma : a rapid systematic review
(2007-09-07T15:28:19Z) Burr, Jennifer Margaret; Fraser, Cynthia Mary
Minimally invasive therapies for the treatment of benign prostatic enlargement : systematic review of randomised controlled trials
(BMJ, 2008-10-09) Lourenco, Tania; Pickard, Robert; Vale, Luke David; Grant, Adrian Maxwell; Fraser, Cynthia Mary; MacLennan, Graeme Stewart; N'Dow, James Michael Olu; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
Objective: To compare the effectiveness and risk profile of minimally invasive interventions against the current standard of transurethral resection of the prostate. Design Systematic review and meta-analysis of randomised controlled trials. Data sources Electronic and paper records up to March 2006. Review methods: We searched for all relevant randomised controlled trials. Two reviewers independently extracted data and assessed quality. Meta-analyses of prespecified outcomes were performed with fixed and random effects models and reported using relative risks or weighted mean difference. Results 3794 abstracts were identified; 22 randomised controlled trials met the inclusion criteria. These provided data on 2434 participants. The studies evaluated were of moderate to poor quality with small sample sizes. Minimally invasive interventions were less effective than transurethral resection of the prostate in terms of improvement in symptom scores and increase in urine flow rate, with most comparisons showing significance despite wide confidence intervals. Rates of second operation were significantly higher for minimally invasive treatments. The risk profile of minimally invasive interventions was better than that of transurethral resection, with fewer adverse events. The results, however, showed significant heterogeneity. Conclusion: Which minimally invasive intervention is the most promising remains unclear. Their place in the management of benign prostate enlargement will continue to remain controversial until well designed and well reported randomised controlled trials following CONSORT guidelines prove they are superior and more cost effective than drug treatment or that strategies of sequential surgical treatments are preferred by patients and are more cost effective than the more invasive but more effective tissue ablative interventions such as transurethral resection.
Romiplostim for the treatment of chronic immune or idiopathic thrombocytopenic purpura
(2009-09) Mowatt, Graham; Boachie, Charles; Crowther, Mark; Fraser, Cynthia Mary; Hernandez, Rodolfo Andres; Jia, Xueli; Ternent, Laura; University of Aberdeen.Other Applied Health Sciences; University of Aberdeen.Health Economics Research Unit
Romiplostim for the treatment of chronic immune or idiopathic thrombocytopenic purpura : a single technology appraisal
(Gray, 2009) Mowatt, Graham; Boachie, C; Crowther, M; Fraser, Cynthia Mary; Hernández, Rodolfo Andrés; Jia, X; Ternent, Laura
This paper presents a summary of the evidence review group (ERG) report into the clinical and cost-effectiveness of romiplostim for the treatment of adults with chronic immune or idiopathic thrombocytopenic purpura (ITP) based upon a review of the manufacturer’s submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submission’s evidence came from two relatively high-quality randomised controlled trials (RCTs). The ERG found no evidence that any important data were missed or that data extraction was inaccurate. In both RCTs more patients in the romiplostim than in the placebo group achieved a durable platelet response [non-splenectomised patients: romiplostim 25/41 (61%), placebo 1/21 (5%), odds ratio (OR) 24.45, 95% confidence interval (CI) 3.34 to 179.18; splenectomised patients: romiplostim 16/42 (38%), placebo 0/21 (0%), OR 8.5 (95% CI 1.15 to 372)] and an overall platelet response [non splenectomised patients: romiplostim 36/41 (88%), placebo 3/21 (14%), OR 34.74, 95% CI 7.77 to 155.38; splenectomised patients: romiplostim 33/42 (79%), placebo 0/21 (0%), OR 16.6 (95% CI 2.37 to 706]. The difference in mean period with a platelet response was 13.9 weeks (95% CI 10.5 to 17.4) in favour of romiplostim in the RCT of non-splectomised patients and 12.1 weeks (95% CI 8.7 to 15.6) in favour of romiplostim in the RCT of splectomised patients. The manufacturer’s economic model evaluated the cost-effectiveness of romiplostim compared with standard care. The ERG had concerns about the way the decision problem was addressed in the economic model and about the non-adjustment of findings for confounding factors. In non-splenectomised patients, using romiplostim as a first option treatment, the base-case incremental costeffectiveness ratio (ICER) was £14,840 per quality adjusted life-year (QALY). In splenectomised patients the ICER was £14,655 per QALY. Additional sensitivity analyses performed by the ERG identified two issues of importance: whether individuals entered the model on watch and rescue or on active therapy in the comparator arm (ICER £21,674 per QALY for non-splenectomised patients, £29,771 per QALY for splenectomised patients); whether it was assumed that any unused medicine would be wasted. Combining all of the separate sensitivity analyses, and assuming that watch and rescue was not the first-line treatment, increased the ICERs further (non-splenectomised £37,290 per QALY; splenectomised £131,017 per QALY). In conclusion, the manufacturer’s submission and additional work conducted by the ERG suggest that romiplostim has short-term efficacy for the treatment of ITP, but there is no robust evidence on long-term effectiveness or cost-effectiveness of romiplostim compared with relevant comparators.
Screening tests for detecting open angle glaucoma : systematic review and meta-analysis
(The Association for Research in Vision and Ophthalmology, Inc., 2008-07-09) Mowatt, Graham; Burr, Jennifer Margaret; Cook, Jonathan Alistair; Siddiqui, M. A. Rehman; Ramsay, Craig R; Fraser, Cynthia Mary; Azuara-Blanco, Augusto; Deeks, Jonathan J
PURPOSE. To assess the comparative accuracy of potential screening tests for open angle glaucoma (OAG). METHODS. Medline, Embase, Biosis (to November 2005), Science Citation Index (to December 2005), and The Cochrane Library (Issue 4, 2005) were searched. Studies assessing candidate screening tests for detecting OAG in persons older than 40 years that reported true and false positives and negatives were included. Meta-analysis was undertaken using the hierarchical summary receiver operating characteristic model. RESULTS. Forty studies enrolling over 48,000 people reported nine tests. Most tests were reported by only a few studies. Frequency-doubling technology (FDT; C-20-1) was significantly more sensitive than ophthalmoscopy (30, 95% credible interval [CrI] 0–62) and Goldmann applanation tonometry (GAT; 45, 95% CrI 17–68), whereas threshold standard automated perimetry (SAP) and Heidelberg Retinal Tomograph (HRT II) were both more sensitive than GAT (41, 95% CrI 14–64 and 39, 95% CrI 3–64, respectively). GAT was more specific than both FDT C-20-5 (19, 95% CrI 0-53) and threshold SAP (14, 95% CrI 1-37). Judging performance by diagnostic odds ratio, FDT, oculokinetic perimetry, and HRT II are promising tests. Ophthalmoscopy, SAP, retinal photography, and GAT had relatively poor performance as single tests. These findings are based on heterogeneous data of limited quality and as such are associated with considerable uncertainty. CONCLUSIONS. No test or group of tests was clearly superior for glaucoma screening. Further research is needed to evaluate the comparative accuracy of the most promising tests.
So many filters, so little time : the development of a search filter appraisal checklist
(MLA, 2008-10) Glanville, Julie; Bayliss, Sue; Booth, Andrew; Dundar, Yenal; Fernandez, Hasina; Fleeman, Nigel David; Foster, Louise; Fraser, Cynthia Mary; Fry-Smith, Anne; Golder, Su; Lefebvre, Carol; Miller, Caroline; Paisley, Suzy; Payne, Liz; Price, Alison; Welch, Karen
Objectives: The authors developed a tool to assess the quality of search filters designed to retrieve records for studies with specific research designs (e.g., diagnostic studies). Methods: The UK InterTASC Information Specialists' Sub-Group (ISSG), a group of experienced health care information specialists, reviewed the literature to evaluate existing search filter appraisal tools and determined that existing tools were inadequate for their needs. The group held consensus meetings to develop a new filter appraisal tool consisting of a search filter appraisal checklist and a structured abstract. ISSG members tested the final checklist using three published search filters. Results: The detailed ISSG Search Filter Appraisal Checklist captures relevance criteria and methods used to develop and test search filters. The checklist includes categorical and descriptive responses and is accompanied by a structured abstract that provides a summary of key quality features of a filter. Discussion: The checklist is a comprehensive appraisal tool that can assist health sciences librarians and others in choosing search filters. The checklist reports filter design methods and search performance measures, such as sensitivity and precision. The checklist can also aid filter developers by indicating information on core methods that should be reported to help assess filter suitability. The generalizability of the checklist for non-methods filters remains to be explored.
Systematic review of economic evaluations of laparoscopic surgery for colorectal cancer
(Wiley-Blackwell, 2008) Hernández, Rodolfo Andrés; De Verteuil, Robyn; Fraser, Cynthia Mary; Vale, Luke David; Aberdeen Health Technology Assessment Group; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
Objective Colorectal cancer is one of the most common cancers and the standard surgical treatment for this cancer is open resection (OS), but laparoscopic surgery (LS) may be an alternative treatment. In 2000, a Health Technology Assessment (HTA) review found little evidence on costs and cost-effectiveness in comparing the two methods. The evidence base has since expanded and this study systematically reviews the economic evaluations on the subject published since 2000. Method Systematic review of studies reporting costs and outcomes of LS vs OS for colorectal cancer. National Health Service Economic Evaluation Database (NHS EED) methods for abstract writing were followed. Studies were summarized and incremental cost-effectiveness ratios (ICER) for common outcomes were calculated. Results Five studies met the inclusion criteria. LS generally had higher healthcare costs. Most studies reported longer operational time and shorter length of stay and similar long-term outcomes with LS vs OS. Only one outcome, complications, was common across all studies but results lacked consistency (e.g. in two studies, OS was less costly but more effective; in another study, LS was less costly but more effective; and in the further two studies, LS could potentially be cost effective depending on the decision-makers' willingness to pay for the health gain). Conclusion The evidence on cost-effectiveness is not consistent. LS was generally more costly than OS. However, the effectiveness data used in individual economic evaluation were imprecise and unreliable when compared with data from systematic reviews of effectiveness. Nevertheless, short-term benefits of LS (e.g. shorter recovery) may make LS appear less costly when productivity gains are considered.
Systematic review of the clinical effectiveness and cost-effectiveness and economic modelling of minimal incision total hip replacement approaches in the management of arthritic disease of the hip
(Gray Publishing, 2008-06) De Verteuil, Robyn; Imamura, Mari; Zhu, S.; Glazener, Cathryn Margaret Anne; Fraser, Cynthia Mary; Munro, N.; Hutchison, James Douglas; Grant, Adrian Maxwell; Coyle, D.; Coyle, K.; Vale, Luke David; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Medicine
Objectives: To assess the clinical effectiveness and cost-effectiveness of minimal incision approaches to total hip replacement (THR) for arthritis of the hip. Data sources: Major electronic databases were searched from 1966 to 2007. Relevant websites were also examined and experts in the field were consulted. Review methods: Studies of minimal (one or two) incision THR compared with standard THR were assessed for inclusion in the review of clinical effectiveness. A systematic review of economic evaluations comparing a minimal incision approach to standard THR was also performed and the estimates from the systematic review of clinical effectiveness were incorporated into an economic model. Utilities data were sourced to estimate quality-adjusted life-years (QALYs). Due to lack of data, no economic analysis was conducted for the two mini-incision surgical method. Results: Nine randomised controlled trials (RCTs), 17 non-randomised comparative studies, six case series and one registry were found to be useful for the comparison of single mini-incision THR with standard THR. One RCT compared two mini-incision THR with standard THR, and two RCTs, five non-randomised comparative studies and two case series compared two mini-incision with single mini-incision THR. The RCTs were of moderate quality. Most had fewer than 200 patients and had a follow-up period of less than 1 year. The single mini-incision THR may have some perioperative advantages, e.g. blood loss [weighted mean difference (WMD) –57.71 ml, p < 0.01] and shorter operative time, of uncertain practical significance. It may also offer a shorter recovery period and greater patient satisfaction. Evidence on long-term outcomes (especially revision) is too limited to be useful. Lack of data prevented subgroup analysis. With respect to the two-incision approach, data were suggestive of shorter recovery compared with single-incision THR, but conclusions must be treated with caution. The costs to the health service, per patient, of single mini-incision THR depend upon assumptions made, but are similar at 1 year (£7060 vs £7350 for standard THR). For a 40-year time horizon the costs were £11,618 for mini-incision and £11,899 for standard THR. Two existing economic evaluations were identified, but they added little, if any, value to the current evidence base owing to their limited quality. In the economic model, mini-incision THR was less costly and provided slightly more QALYs in both the 1- and 40-year analyses. The mean QALYs at 1 year were 0.677 for standard THR and 0.695 for mini-incision THR. At 40 years, the mean QALYs were 8.463 for standard THR and 8.480 for mini-incision. At 1 year the probabilistic sensitivity analyses indicate that mini-incision THR has a 95% probability of being cost-effective if society’s willingness to pay for a QALY were up to £50,000. This is reduced to approximately 55% for the 40-year analysis. The results were driven by the assumption of a 1-month earlier return to usual activities and a decreased hospital length of stay and operation duration following mini-incision THR. If mini-incision THR actually required more intensive use of resources it would become approximately £200 more expensive and would only be cost-effective (cost per QALY > £30,000) if recovery was 1.5 weeks faster. A threshold analysis around risk of revision showed, using the same cost per QALY threshold, mini-incision THR would have to have no more than a 7.5% increase in revisions compared with standard THR for it to be no longer considered cost-effective (one more revision for every 200 procedures performed). Further sensitivity analysis involved relaxing assumptions of equal long-term outcomes where possible. and broadly similar results to the base-case analysis were found in this and further sensitivity analyses. Conclusions: Compared with standard THR, minimal incision THR has small perioperative advantages in terms of blood loss and operation time. It may offer a shorter hospital stay and quicker recovery. It appears to have a similar procedure cost to standard THR, but evidence on its longer term performance is very limited. Further long-term follow-up data on costs and outcomes including analysis of subgroups of interest to the NHS would strengthen the current economic evaluation.
Systematic review of the clinical effectiveness and cost-effectiveness of 64-slice or higher computed tomography angiography as an alternative to invasive coronary angiography in the investigation of coronary artery disease
(Gray Publishing, 2008-05) Mowatt, Graham; Cummins, E.; Waugh, N.; Walker, S.; Cook, Jonathan Alistair; Jia, Xueli; Hillis, Graham S.; Fraser, Cynthia Mary
Objectives: To assess the clinical effectiveness and cost-effectiveness, in different patient groups, of the use of 64-slice or higher computed tomography (CT) angiography, instead of invasive coronary angiography (CA), for diagnosing people with suspected coronary artery disease (CAD) and assessing people with known CAD. Data sources: Electronic databases were searched from 2002 to December 2006. Review methods: Included studies were tabulated and sensitivity, specificity, positive and negative predictive values calculated. Meta-analysis models were fitted using hierarchical summary receiver operating characteristic curves. Summary sensitivity, specificity, positive and negative likelihood ratios and diagnostic odds ratios for each model were reported as a median and 95% credible interval (CrI). Searches were also carried out for studies on the cost-effectiveness of 64-slice CT in the assessment of CAD. Results: The diagnostic accuracy and prognostic studies enrolled over 2500 and 1700 people, respectively. The overall quality of the studies was reasonably good. In the pooled estimates, 64-slice CT angiography was highly sensitive (99%, 95% CrI 97 to 99%) for patientbased detection of significant CAD (defined as 50% or more stenosis), while across studies the negative predictive value (NPV) was very high (median 100%, range 86 to 100%). In segment-level analysis compared with patient-based detection, sensitivity was lower (90%, 95% CrI 85 to 94%, versus 99%, 95% CrI 97 to 99%) and specificity higher (97%, 95% CrI 95 to 98%, versus 89%, 95% CrI 83 to 94%), while across studies the median NPV was similar (99%, range 95 to 100%, versus 100%, range 86 to 100%). At individual coronary artery level the pooled estimates for sensitivity ranged from 85% for the left circumflex (LCX) artery to 95% for the left main artery, specificity ranged from 96% for both the left anterior descending (LAD) artery and LCX to 100% for the left main artery, while across studies the positive predictive value (PPV) ranged from 81% for the LCX to 100% for the left main artery and NPV was very high, ranging from 98% for the LAD (range 95 to 100%), LCX (range 93 to 100%) and right coronary artery (RCA) (range 94 to 100%) to 100% for the left main artery. The pooled estimates for bypass graft analysis were 99% (95% CrI 95 to 100%) sensitivity, 96% (95% CrI 86 to 99%) specificity, with median PPV and NPV values across studies of 93% (range 90 to 95%) and 99% (range 98 to 100%), respectively. This compares with, for stent analysis, a pooled sensitivity of 89% (95% CrI 68 to 97%), specificity 94% (95% CrI 83 to 98%), and median PPV and NPV values across studies of 77% (range 33 to 100%) and 96% (range 71 to 100%), respectively. Sixty-four-slice CT is almost as good as invasive CA in terms of detecting true positives. However, it is somewhat poorer in its rate of false positives. It seems likely that diagnostic strategies involving 64-slice CT will still require invasive CA for CT test positives, partly to identify CT false positives, but also because CA provides other information that CT currently does not, notably details of insertion site and distal run-off for possible coronary artery bypass graft (CABG). The high sensitivity of 64-slice CT avoids the costs of unnecessary CA in those referred for investigation but who do not have CAD. Given the possible, although small, associated death rate, avoiding these unnecessary CAs through the use of 64-slice CT may also confer a small immediate survival advantage. This in itself may be sufficient to outweigh the very marginally inferior rates of detection of true positives by strategies involving 64-slice CT. The avoidance of unnecessary CA through the use of 64-slice CT also appears likely to result in overall cost savings in the diagnostic pathway. Only if both the cost of CA is relatively low and the prevalence of CAD in the presenting population is relatively high (so that most patients will go on to CA) will the use of 64-slice CT be likely to result in a higher overall diagnostic cost per patient. Conclusions: The main value of 64-slice CT may at present be to rule out significant CAD. It is unlikely to replace CA in assessment for revascularisation of patients, particularly as angiography and angioplasty are often done on the same occasion. Further research is needed into the marginal advantages and costs of 256-slice machines compared with 64-sliceCT, the usefulness of 64-slice CT in people with suspected acute coronary syndrome, the potential of multislice computed tomography to examine plaque morphology, the role of CT in identifying patients suitable for CABG, and the concerns raised about repetitive use, or use of 64-slice or higher CT angiography in younger individuals or women of childbearing age.
Systematic review of the clinical effectiveness and cost-effectiveness of laparoscopic surgery for inguinal hernia repair.
(2005) McCormack, Kirsty; Wake, B.; Gonzalez Perez, Juan Gregorio; Fraser, Cynthia Mary; Cook, Jonathan Alistair; McIntosh, Emma; Vale, Luke David; Grant, Adrian Maxwell; University of Aberdeen.Other Applied Health Sciences
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 Sciences
Objectives: 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.
Systematic review of the effectiveness and cost-effectiveness of Healozone for the treatment of occlusal pit/fissure caries and root caries.
(Gray Publishing, 2006-05) Brazzelli, M; McKenzie, L.; Fielding, Shona; Fraser, Cynthia Mary; Clarkson, J.; Kilonzo, Mary Mueni; Waugh, N.
Systematic review of the effectiveness of preventing and treating Staphylococcus aureus carriage in reducing peritoneal catheter-related infections
(Gray Publishing, 2007-07) McCormack, Kirsty; Rabindranath, K.; Kilonzo, Mary Mueni; Vale, Luke David; Fraser, Cynthia Mary; McIntyre, L.; Thomas, Sumesh; Rothnie, H.; Fluck, N.; Gould, Ian M; Waugh, Norman Robert; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
Objectives: To determine the clinical effectiveness and cost-effectiveness of (1) alternative strategies for the prevention of Staphylococcus aureus carriage in patients on peritoneal dialysis (PD) and (2) alternative strategies for the eradication of S. aureus carriage in patients on PD. Data sources: Major electronic databases were searched up to December 2005 (MEDLINE Extra up to 6 January 2006). Review methods: Electronic searches were undertaken to identify published and unpublished reports of randomised controlled trials and systematic reviews evaluating the effectiveness of preventing and treating S. aureus carriage on peritoneal catheterrelated infections. The quality of the included studies was assessed and data synthesised. Where data were not sufficient for formal meta-analysis, a qualitative narrative review looking for consistency between studies was performed. Results: Twenty-two relevant trials were found. These fell into several groups: the first split is between prophylactic trials, aiming to prevent carriage, and trials which aimed to eradicate carriage in those who already had it; the second split is between antiseptics and antibiotics; and the third split is between those that included patients having the catheter inserted before dialysis started and people already on dialysis. Many of the trials were small or short-term. The quality was often not good by today’s standards. The body of evidence suggested a reduction in exit-site infections, but this did not seem to lead to a significant reduction in peritonitis, although to some extent this reflected insufficient power in the studies and a low incidence of peritonitis in them. The costs of interventions to prevent or treat S. aureus carriage are relatively modest. For example, the annual cost of antibiotic treatment of S. aureus carriage per identified carrier of S. aureus was estimated at £179 (£73 screening and £106 cost of antibiotic). However, without better data on the effectiveness of the interventions, it is not clear whether such costs are offset by the cost of treating infections and averting changes from peritoneal dialysis to haemodialysis. Although treatment is not expensive, the lack of convincing evidence of clinical effectiveness made cost-effectiveness analysis unrewarding at present. However, consideration was given to the factors needed in a hypothetical model describing patient pathways from methods to prevent S. aureus carriage, its detection and treatment and the detection and treatment of the consequences of S. aureus (e.g. catheter infections and peritonitis). Had data been available, the model would have compared the costeffectiveness of alternative interventions from the perspective of the UK NHS, but as such it helped identify what future research would be needed to fill the gaps. Conclusions: The importance of peritonitis isnot in doubt. It is the main cause of people having to switch from peritoneal dialysis to haemodialysis, which then leads to reduced quality of life for patients and increased costs to the NHS. Unfortunately, the present evidence base for the prevention of peritonitis is disappointing; it suggests that the interventions reduce exit-site infections, but not peritonitis, although this may be due to trials being in too small numbers for too short periods. Trials are needed with larger numbers of patients for longer durations.