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Carroll C, Stevenson M, Scope A, Evans P, Buckley S. Hemiarthroplasty and total hip arthroplasty for treating primary intracapsular fracture of the hip: a systematic review and cost-effectiveness analysis. Health Technol Assess 2012; 15:1-74. [PMID: 21978400 DOI: 10.3310/hta15360] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Hip fracture is a common problem in people aged > 60 years. The treatment options for individuals with high pre-fracture mobility, function and independence are hemiarthroplasty (HA) and total hip arthroplasty (THA). OBJECTIVE The aim of this report is to assess the clinical effectiveness and cost-effectiveness evidence of THA compared with HA in patients with displaced intracapsular fracture who are cognitively intact with high pre-fracture mobility or function. DATA SOURCES A systematic search was made of 11 databases of published and unpublished literature from their inception to december 2010: MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library, Biological Science Citation Index, Social Science Citation Index, Conference Proceedings Citation Index - Science, UK Clinical Trials Research Network and the National Research Register archive, Current Controlled Trials and ClinicalTrials.gov. REVIEW METHODS A systematic review of randomised controlled trials (RCTs) to assess the effectiveness of THA compared with HA in terms of dislocations, revisions, pain and function, and quality of life. Meta-analysis, independent subgroup analyses and exploratory cost-effectiveness modelling were performed. RESULTS The literature search identified 532 unique citations, of which eight RCTs with almost 1000 participants satisfied the criteria for the effectiveness review. Meta-analysis found a statistically significant increased risk of dislocation for patients treated with THA compared with HA (p = 0.01), but a reduced risk of revision (p = 0.0003). There were no differences in terms of mortality. In all trials, individuals treated with THA reported better function and mobility and less pain than those treated with HA. Four trials reporting utility data found similar trends. Sensitivity analyses indicated that there were no statistically significant differences in outcomes based on follow-up, study quality, surgical approach taken, type of head or the use of cement. Four papers reported a cost-utility analysis or the cost-effectiveness of THA compared with HA. Exploratory modelling was undertaken that showed that THA is likely to be cost-effective compared with HA even when the limitations of the data and methodology are considered. LIMITATIONS The costs and disutilities associated with revisions and dislocations were not included in the economic evaluation. CONCLUSIONS THA appears to be more cost-effective than HA. It is likely that THA will be associated with increased costs in the initial 2-year period, but lower longer-term costs, owing to potentially lower revision rates. However, these longer-term costs have not been modelled. The capacity and experience of surgeons to perform THA have not been explored and these would need to be addressed at local level were THA to become recommended for active, elderly patients in whom THA is not contraindicated. Further studies examining the impact of surgeon experience on performing the two procedures may offer more robust evidence on outcomes. FUNDING The National Institute for Health Research Health Technology Assessment programme.
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Pandor A, Goodacre S, Harnan S, Holmes M, Pickering A, Fitzgerald P, Rees A, Stevenson M. Diagnostic management strategies for adults and children with minor head injury: a systematic review and an economic evaluation. Health Technol Assess 2011; 15:1-202. [PMID: 21806873 DOI: 10.3310/hta15270] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Patients with minor head injury [Glasgow Coma Scale (GCS) score 13-15] have a small but important risk of intracranial injury (ICI) that requires early identification and neurosurgical treatment. Diagnostic assessment can use either a clinical decision rule or unstructured assessment of individual clinical features to identify those who are at risk of ICI and in need of computerised tomography (CT) scanning and/or hospital admission. Selective use of CT investigations helps minimise unnecessary radiation exposure and resource use, but can lead to missed opportunities to provide early treatment for ICI. OBJECTIVES To determine the diagnostic accuracy of decision rules, individual clinical characteristics, skull radiography and biomarkers, and the clinical effectiveness and cost-effectiveness of diagnostic management strategies for minor head injury (MHI). DATA SOURCES Several electronic databases [including MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, Cumulative Index to Nursing and Allied Health Literature (CINAHL), EMBASE and The Cochrane Library] were searched from inception to April 2009 (updated searches to March 2010 were conducted on the MEDLINE databases only). Searches were supplemented by hand-searching relevant articles (including citation searching) and contacting experts in the field. For each of the systematic reviews the following studies were included (1) cohort studies of patients with MHI in which a clinical decision rule or individual clinical characteristics (including biomarkers and skull radiography) were compared with a reference standard test for ICI or need for neurosurgical intervention and (2) controlled trials comparing alternative management strategies for MHI. REVIEW METHODS Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool (for the assessment of diagnostic accuracy) or criteria recommended by the Effective Practice and Organisation of Care Review Group (for the assessment of management practices). Where sufficient data existed, a meta-analysis was undertaken to generate pooled estimates of diagnostic parameters. A decision-analysis model was developed using Simul8 2008 Professional software (Simul8 Corporation, Boston, MA, USA) to estimate the costs and quality-adjusted life-years (QALYs) accrued by management strategies for MHI. The model took a lifetime horizon and NHS perspective. Estimates of the benefits of early treatment, harm of radiation exposure and long-term costs were obtained through literature reviews. Initial analysis was deterministic, but probabilistic sensitivity analysis was also performed. Secondary analyses were undertaken to explore the trade-off between sensitivity and specificity in diagnostic strategies and to determine the cost-effectiveness of scenarios involving hospital admission. RESULTS The literature searches identified 8003 citations. Of these, 93 full-text papers were included for the assessment of diagnostic accuracy and one for the assessment of management practices. The quality of studies and reporting was generally poor. The Canadian CT Head Rule (CCHR) was the most widely validated adult rule, with sensitivity of 99-100% and 80-100% for neurosurgical and any ICI, respectively (high- or medium-risk criteria), and specificity of 39-51%. Rules for children had high sensitivity and acceptable specificity in derivation cohorts, but limited validation. Depressed, basal or radiological skull fracture and post-traumatic seizure (PTS) [positive likelihood ratio (PLR) > 10]; focal neurological deficit, persistent vomiting, decrease in GCS and previous neurosurgery (PLR 5-10); and fall from a height, coagulopathy, chronic alcohol use, age > 60 years, pedestrian motor vehicle accident (MVA), any seizure, undefined vomiting, amnesia, GCS < 14 and GCS < 15 (PLR 2-5) increased the likelihood of ICI in adults. Depressed or basal skull fracture and focal neurological deficit (PLR > 10), coagulopathy, PTS and previous neurosurgery (PLR 5-10), visual symptoms, bicycle and pedestrian MVA, any seizure, loss of consciousness, vomiting, severe or persistent headache, amnesia, GCS < 14, GCS < 15, intoxication and radiological skull fracture (PLR 2-5) increased the likelihood of ICI in children. S100 calcium-binding protein B had pooled sensitivity of 96.8% [95% highest-density region (HDR) 93.8% to 98.6%] and specificity of 42.5% (95% HDR 31.0% to 54.2%). The only controlled trial showed that early CT and discharge is cheaper and at least as effective as hospital admission. Economic analysis showed that selective CT use dominated 'CT all' and 'discharge all' strategies. The optimal strategies were the CCHR (adults) and the CHALICE (Children's Head injury Algorithm for the prediction of Important Clinical Events) or NEXUS II (National Emergency X-Radiography Utilization Study II) rule (children). The sensitivity and specificity of the CCHR (99% and 47%, respectively) represented an appropriate trade-off of these parameters. Hospital admission dominated discharge home for patients with non-neurosurgical injury, but cost £39 M per QALY for clinically normal patients with a normal CT. CONCLUSIONS The CCHR is widely validated and cost-effective for adults. Decision rules for children appear cost-effective, but need further validation. Hospital admission is cost-effective for patients with abnormal, but not normal, CT. The main research priorities are to (1) validate decision rules for children; (2) determine the prognosis and treatment benefit for non-neurosurgical injuries; (3) evaluate the use of S100B alongside a validated decision rule; (4) evaluate the diagnosis and outcomes of anticoagulated patients with MHI; and (5) evaluate the implementation of guidelines, clinical decision rules and diagnostic strategies. Formal expected value of sample information analysis would be recommended to appraise the cost-effectiveness of future studies. FUNDING The National Institute for Health Research Health Technology Assessment programme.
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Boufous S, Ivers R, Senserrick T, Stevenson M, Norton R, Williamson A. P2-501 Accuracy of self-report of on-road crashes and traffic offences in a cohort of young drivers: the drive study. Br J Soc Med 2011. [DOI: 10.1136/jech.2011.142976m.28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Boufous S, Ali M, Nguyen H, Stevenson M, Ivers R, Viet CP, Nguyen A. SP3-22 Child injury prevention in Vietnam: achievements and challenges. Br J Soc Med 2011. [DOI: 10.1136/jech.2011.142976o.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Dunowska M, Howe L, Hanlon D, Stevenson M. Kinetics of Equid herpesvirus type 2 infections in a group of Thoroughbred foals. Vet Microbiol 2011; 152:176-80. [DOI: 10.1016/j.vetmic.2011.04.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 04/08/2011] [Accepted: 04/14/2011] [Indexed: 01/08/2023]
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Donnelly J, Winder J, Kernohan W, Stevenson M. An RCT to determine the effect of a heel elevation device in pressure ulcer prevention post-hip fracture. J Wound Care 2011; 20:309-12, 314-8. [DOI: 10.12968/jowc.2011.20.7.309] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Lugasi T, Achille M, Stevenson M. Patients' perspective on factors that facilitate transition from child-centered to adult-centered health care: a theory integrated metasummary of quantitative and qualitative studies. J Adolesc Health 2011; 48:429-40. [PMID: 21501800 DOI: 10.1016/j.jadohealth.2010.10.016] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 10/28/2010] [Accepted: 10/30/2010] [Indexed: 11/25/2022]
Abstract
PURPOSE The purpose of this review was twofold. First, to summarize systematically the state of the research conducted on the perspective of patients on transition from child-centered care to adult-centered care (ACC). Second, based on this review of patients' perspective, to identify factors that facilitate transition to ACC. METHODS Using a metasummary methodology, we extracted, grouped, and abstracted the findings from 46 qualitative and descriptive quantitative studies involving patients before and/or after their transfer to ACC. RESULTS Empirical results on transition fall into four groups: (1) patients' feelings and concerns; (2) patients' recommendations about transition; (3) outcomes after transfer; and (4) mode of transfer. CONCLUSIONS Results are discussed within a theoretical transition framework that emphasizes the importance of fulfilling five conditions that will lead to successful transition. Given our findings, this synthesis and framework can be used to tailor transition care and direct future research.
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Stevenson M, Baillie AJ, Richards RME. Antibacterial Activity of Liposome Entrapped Chloramphenicol. J Pharm Pharmacol 2011. [DOI: 10.1111/j.2042-7158.1981.tb11690.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Stevenson M, Baillie AJ, Richards RME. Streptomycin Inactivation of Intracellular Escherichia Coli. J Pharm Pharmacol 2011. [DOI: 10.1111/j.2042-7158.1982.tb00888.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Stevenson M, Baillie AJ, Richards RME. Endocytosis of Escherichia Coli by Macrophages. J Pharm Pharmacol 2011. [DOI: 10.1111/j.2042-7158.1982.tb00887.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ara R, Pandor A, Stevens J, Rafia R, Ward SE, Rees A, Durrington PN, Reynolds TM, Wierzbicki AS, Stevenson M. Prescribing high-dose lipid-lowering therapy early to avoid subsequent cardiovascular events: is this a cost-effective strategy? Eur J Prev Cardiol 2011; 19:474-83. [PMID: 21460076 DOI: 10.1177/1741826711406616] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND While evidence shows high-dose statins reduce cardiovascular events compared with moderate doses in individuals with acute coronary syndrome (ACS), many primary care trusts (PCT) advocate the use of generic simvastatin 40 mg/day for these patients. METHODS AND RESULTS Data from 28 RCTs were synthesized using a mixed treatment comparison model. A Markov model was used to evaluate the cost-effectiveness of treatments taking into account adherence and the likely reduction in cost for atorvastatin when the patent expires. There is a clear dose-response: rosuvastatin 40 mg/day produces the greatest reduction in low-density lipoprotein cholesterol (56%) followed by atorvastatin 80 mg/day (52%), and simvastatin 40 mg/day (37%). Using a threshold of £20,000 per QALY, if adherence levels in general practice are similar to those observed in RCTs, all three higher dose statins would be considered cost-effective compared to simvastatin 40 mg/day. Using the net benefits of the treatments, rosuvastatin 40 mg/day is estimated to be the most cost-effective alternative. If the cost of atorvastatin reduces in line with that observed for simvastatin, atorvastatin 80 mg/day is estimated to be the most cost-effective alternative. CONCLUSION Our analyses show that current PCT policies intended to minimize primary care drug acquisition costs result in suboptimal care.
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Oladipo O, Conlon S, O'Grady A, Purcell C, Wilson C, Maxwell PJ, Johnston PG, Stevenson M, Kay EW, Wilson RH, Waugh DJJ. The expression and prognostic impact of CXC-chemokines in stage II and III colorectal cancer epithelial and stromal tissue. Br J Cancer 2011; 104:480-7. [PMID: 21285972 PMCID: PMC3049559 DOI: 10.1038/sj.bjc.6606055] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background: The CXC-chemokine expression is linked with colorectal cancer (CRC) progression but their significance in resected CRC is unclear. We explored the prognostic impact of such expression in stage II and III CRC. Methods: Tissue microarrays were constructed from stage II and III CRC biopsies (n=254), and the expression of CXCL1 and CXCL8, and their receptors CXCR1 and CXCR2, in malignant and adjacent normal tissue was graded by immunohistochemistry and was correlated with prognostic factors. Results: Expression of CXCL1, CXCR1 and CXCR2 was elevated in tumour epithelium relative to normal adjacent tissue (P<0.001). CXCL8 expression was detectable in the peritumoural inflammatory infiltrate. There was no overall association between CXCL1, CXCR1 or CXCR2 expression and prognostic endpoints; however, univariate subgroup survival analysis demonstrated an inverse association between CXCL1 and recurrence-free survival (RFS) in stage III patients (P=0.041). The CXCL8 positivity in the tumour infiltrate, however, correlated with earlier disease stage (P<0.001) and improved relapse-free survival across the cohort (P<0.001). Disease stage (P<0.001) and tumour infiltrate CXCL8 positivity (P=0.007) were associated with enhanced RFS in multivariate Cox regression analysis. Conclusion: Autocrine CXC-chemokine signalling may have adverse prognostic effects in early CRC. Conversely, CXCL8 positivity within the immune infiltrate may have good prognostic significance.
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Whyte S, Pandor A, Stevenson M, Rees A. Bevacizumab in combination with fluoropyrimidine-based chemotherapy for the first-line treatment of metastatic colorectal cancer. HEALTH TECHNOLOGY ASSESSMENT (WINCHESTER, ENGLAND) 2011; 14:47-53. [PMID: 21047491 DOI: 10.3310/hta14suppl2/07] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of bevacizumab in combination with fluoropyrimidine-based chemotherapy for the first-line treatment of metastatic colorectal cancer based on the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. Evidence was available in the form of one phase III, multicentre, multinational, randomised, open-label study (NO16966 trial). This two-arm study was originally designed to demonstrate the non-inferiority of oral capecitabine plus oxaliplatin (XELOX) compared with 5-fluorouracil plus folinic acid plus oxaliplatin (FOLFOX)-4 in adult patients with histologically confirmed metastatic colorectal cancer who had not previously been treated. Following randomisation of 634 patients, the open-label study was amended to include a 2 × 2 factorial randomised (partially blinded for bevacizumab) phase III trial with the coprimary objective of demonstrating superiority of bevacizumab in combination with chemotherapy compared with chemotherapy alone. Measured outcomes included overall survival, progression-free survival, response rate, adverse effects of treatment and health-related quality of life. The manufacturer's primary pooled analysis of superiority (using the intention-to-treat population) showed that after a median follow-up of 28 months, the addition of bevacizumab to chemotherapy significantly improved progression-free survival and overall survival compared with chemotherapy alone in adult patients with histologically confirmed metastatic colorectal cancer who were not previously treated [median progression-free survival 9.4 vs 7.7 months (absolute difference 1.7 months); hazard ratio (HR) 0.79, 97.5% confidence interval (CI) 0.72 to 0.87; p = 0.0001; median overall survival 21.2 vs 18.9 months (absolute difference 2.3 months); HR 0.83, 97.5% CI 0.74 to 0.93; p = 0.0019]. The NO16966 trial was of reasonable methodological quality and demonstrated a significant improvement in both progression-free survival and overall survival when bevacizumab was added to XELOX or FOLFOX. However, the size of the actual treatment effect of bevacizumab is uncertain. The ERG believed that the modelling structure employed was appropriate, but highlighted several key issues and areas of uncertainty. At the time of writing, NICE was yet to issue the guidance for this appraisal.
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Maund E, McKenna C, Sarowar M, Fox D, Stevenson M, Pepper C, Palmer S, Woolacott N. Dronedarone for the treatment of atrial fibrillation and atrial flutter. HEALTH TECHNOLOGY ASSESSMENT (WINCHESTER, ENGLAND) 2011; 14:55-62. [PMID: 21047492 DOI: 10.3310/hta14suppl2/08] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This paper presents a summary of the evidence review group (ERG) report on the clinical effectiveness and cost-effectiveness of dronedarone for the treatment of atrial fibrillation (AF) or atrial flutter 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 process. The population considered in the submission were adult clinically stable patients with a recent history of or current non-permanent AF. Comparators were the current available anti-arrhythmic drugs: class 1c agents (flecainide and propafenone), sotalol and amiodarone. Outcomes were AF recurrence, all-cause mortality, stroke, treatment discontinuations (due to any cause or due to adverse events) and serious adverse events. The main evidence came from four phase III randomised controlled trials, direct and indirect meta-analyses from a systematic review, and a synthesis of the direct and indirect evidence using a mixed-treatment comparison. Overall, the results from the different synthesis approaches showed that the odds of AF recurrence appeared statistically significantly lower with dronedarone and other anti-arrhythmic drugs than with non-active control, and that the odds of AF recurrence are statistically significantly higher for dronedarone than for amiodarone. However, the results for outcomes of all-cause mortality, stroke and treatment discontinuations and serious adverse events were all uncertain. A discrete event simulation model was used to evaluate dronedarone versus antiarrhythmic drugs and standard therapy alone. The incremental cost-effectiveness ratio of dronedarone was relatively robust and less than 20,000 pounds per quality-adjusted life-year. Exploratory work undertaken by the ERG identified that the main drivers of cost-effectiveness were the benefits assigned to dronedarone for all-cause mortality and stroke. Dronedarone is not cost-effective relative to its comparators when the only effect of treatment is a reduction in AF recurrences. In conclusion, uncertainties remain in the clinical effectiveness and cost-effectiveness of dronedarone. In particular, the clinical evidence for the major drivers of cost-effectiveness (all-cause mortality and stroke), and consequently the additional benefits attributed in the economic model to dronedarone compared to other anti-arrhythmic drugs are highly uncertain. The final guidance, issued by NICE on 25 August 2010, states that: Dronedarone is recommended as an option for the treatment of non-permanent atrial fibrillation only in people: whose atrial fibrillation is not controlled by first-line therapy (usually including beta-blockers), that is, as a second-line treatment option, and who have at least one of the following cardiovascular risk factors: - hypertension requiring drugs of at least two different classes, diabetes mellitus, previous transient ischaemic attack, stroke or systemic embolism, left atrial diameter of 50 mm or greater, left ventricular ejection fraction less than 40% (noting that the summary of product characteristics [SPC] does not recommend dronedarone for people with left ventricular ejection fraction less than 35% because of limited experience of using it in this group) or age 70 years or older, and who do not have unstable New York Heart Association (NYHA) class III or IV heart failure. Furthermore, 'People who do not meet the criteria above who are currently receiving dronedarone should have the option to continue treatment until they and their clinicians consider it appropriate to stop'.
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Clapham K, Khavarpour F, Bolt R, Stevenson M. Child injury in an urban Australian indigenous community: the safe koori kids intervention. Inj Prev 2011. [DOI: 10.1136/ip.2010.029215.495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Stevenson M. Handling and restraining aggressive dogs. Vet Rec 2011; 168:309. [DOI: 10.1136/vr.d1676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Boufous S, Ivers R, Senserrick T, Stevenson M, Norton R, Williamson A. Accuracy of self-report of on-road crashes and traffic offences in a cohort of young drivers: the DRIVE study. Inj Prev 2011. [DOI: 10.1136/ip.2010.029215.290] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Martiniuk ALC, Ivers RQ, Glozier N, Patton GC, Lam LT, Boufous S, Senserrick T, Williamson A, Stevenson M, Norton R. Self-harm and risk of motor vehicle crashes in youth: the DRIVE prospective cohort study. Inj Prev 2011. [DOI: 10.1136/ip.2010.029215.360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Bandyopadhyay S, Canning J, Biswas P, Stevenson M, Dasgupta K. A study of regenerated gratings produced in germanosilicate fibers by high temperature annealing. OPTICS EXPRESS 2011; 19:1198-1206. [PMID: 21263661 DOI: 10.1364/oe.19.001198] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In light of recent proposals linking structural change and stresses within regenerated gratings, the details of regeneration of a seed Type-I Bragg grating written in H2 loaded germanosilicate fiber annealed at high temperatures (~900°C) are systematically explored. In particular, the influence of the strength of the grating, the effect of GeO2 doping concentration and the annealing conditions on regeneration are studied. We show that the role of dopants such as Ge and F contribute nothing to the regeneration, consistent with previous results. Rather, they may potentially be detrimental. Strongest regenerated gratings with R ~35% from a 5mm seed grating could be obtained in fibres with the lowest GeO2 concentrations such as standard telecommunications-compatible grade fibre.
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Benschop J, Spencer S, Alban L, Stevenson M, French N. Bayesian Zero-Inflated Predictive Modelling of Herd-Level Salmonella Prevalence for Risk-Based Surveillance. Zoonoses Public Health 2010; 57 Suppl 1:60-70. [DOI: 10.1111/j.1863-2378.2010.01355.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Owen J, Carroll C, Cooke J, Formby E, Hayter M, Hirst J, Lloyd Jones M, Stapleton H, Stevenson M, Sutton A. School-linked sexual health services for young people (SSHYP): a survey and systematic review concerning current models, effectiveness, cost-effectiveness and research opportunities. Health Technol Assess 2010; 14:1-228, iii-iv. [PMID: 20561461 DOI: 10.3310/hta14300] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Report based on a service-mapping study and a systematic review concerning sexual health services for young people, either based in or closely linked to schools. OBJECTIVES To identify current forms of school-based sexual health services (SBSHS) and school-linked sexual health services (SLSHS) in the UK, review and synthesise existing evidence from qualitative and quantitative studies concerning the effectiveness, acceptability and cost-effectiveness of these types of service and to identify potential areas for further research. DATA SOURCES Electronic databases were searched from 1985 onwards. For published material: the Cochrane Library (1991-), MEDLINE, PREMEDLINE (2007-), CINAHL, EMBASE, AMED, ASSIA (1987-), IBSS, ERIC, PsycINFO, Science Citation Index (SCI) and Social Sciences Citation Index. For unpublished material and grey literature: the Social Care Institute of Excellence Research Register; the National Research Register (1997-), ReFeR; Index to Theses, and HMIC. REVIEW METHODS A service-mapping questionnaire was circulated to school nurses in all parts of the UK, and semistructured telephone interviews with service coordinators in NHS and local authority (LA) roles were conducted. An evidence synthesis was performed based on a systematic review of the quantitative evidence about service effectiveness, qualitative evidence about user and professional views and a mixed-methods synthesis. A proof-of-concept model for assessing cost-effectiveness was drawn up. RESULTS Three broad types of UK sexual health service provision were identified. Firstly, SBSHS staffed by school nurses, offering 'minimal' or 'basic' levels of service. Secondly, SBSHS and SLSHS staffed by a multiprofessional team, but not medical practitioners, offering 'basic' or 'intermediate' levels of service. Thirdly, SBSHS and SLSHS staffed by a multiprofessional team, including medical practitioners offering 'intermediate' or 'comprehensive' levels of service. The systematic review showed that SBSHS are not associated with higher rates of sexual activity among young people, nor with an earlier age of first intercourse. There was evidence to show positive effects in terms of reductions in births to teenage mothers, and in chlamydial infection rates among young men, although this evidence coming primarily from the USA. Therefore, the findings need to be tested in relation to UK-based services. Also evidence to suggest that broad-based, holistic service models, not restricted to sexual health, offer the strongest basis for protecting young people's privacy and confidentiality, countering perceived stigmatisation, offering the most comprehensive range of products and services, and maximising service uptake. Findings from the mapping study also indicate that broad-based services, which include medical practitioner input within a multiprofessional team, meet the stated preferences of staff and of young people most clearly. Partnership-based developments of this kind also conform to the broad policy principles embodied in the Every Child Matters framework in the UK and allied policy initiatives. However, neither these service models nor narrower ones have been rigorously evaluated in terms of their impact on the key outcomes of conception rates and sexually transmitted infection (STI) rates, in the UK or in other countries. Therefore, appropriate data were not found to support cost-effectiveness modelling. LIMITATIONS Low response rate to the questionnaire. Scotland, Wales and Northern Ireland were under-represented. Also, the distinction made in the questionnaire between 'general health' and 'sexual health' services did not prove robust. CONCLUSIONS There is no single, dominant service model in the UK. The systematic review demonstrated that the evidence base for these services remains limited and uneven, and draws largely on US studies. Qualitative research is needed to develop robust process and outcome indicators for the evaluation of SLSHS/SBSHS in the UK. These indicators could then be used both in local evaluations, and in large, longitudinal studies of service effectiveness and cost-effectiveness. Future research should examine the impact of the differing types of services currently evolving in the UK, encompassing school-based and school-linked models, as well as models with and without medical practitioner involvement.
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Song HC, Kim JS, Hodgkiss WS, Kuperman WA, Stevenson M. High-rate multiuser communications in shallow water. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2010; 128:2920-2925. [PMID: 21110587 DOI: 10.1121/1.3488309] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Passive multiuser communications in shallow water previously was demonstrated in the 3-4 kHz band using a time reversal approach. This paper extends those experimental results in three respects. First, a larger bandwidth at higher frequency (11-19 kHz) is employed allowing for the use of various symbol rates (or bandwidths). Second, two different shaping pulses are examined: a raised cosine filter and LFM (linear frequency modulation) chirp. Third, the adaptive time reversal approach with spatial nulling is applied to suppress the crosstalk among users. It is shown that the use of a larger bandwidth is beneficial along with the time reversal receiver which can handle significant intersymbol interference with minimal computational complexity. In addition, adding each user degrades the performance by about 4 dB for the benefit of linear increase in data rate. It is demonstrated that an aggregate data rate of 60 kbits/s can be achieved with a 7.5 kHz bandwidth (a spectral efficiency of 8 bits/s Hz) by three users distributed over 4.2-m depth at a 2.2 km range in shallow water using 16-QAM (quadrature amplitude modulation).
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98
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Agirre E, Soroa A, Stevenson M. Graph-based Word Sense Disambiguation of biomedical documents. Bioinformatics 2010; 26:2889-96. [DOI: 10.1093/bioinformatics/btq555] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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99
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Whyte S, Pandor A, Stevenson M, Rees A. Bevacizumab in combination with fluoropyrimidine-based chemotherapy for the first-line treatment of metastatic colorectal cancer. Health Technol Assess 2010. [DOI: 10.3310/hta14suppl2-07] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of bevacizumab in combination with fluoropyrimidine-based chemotherapy for the first-line treatment of metastatic colorectal cancer based on the manufacturer’s submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. Evidence was available in the form of one phase III, multicentre, multinational, randomised, open-label study (NO16966 trial). This two-arm study was originally designed to demonstrate the non-inferiority of oral capecitabine plus oxaliplatin (XELOX) compared with 5-fluorouracil plus folinic acid plus oxaliplatin (FOLFOX)-4 in adult patients with histologically confirmed metastatic colorectal cancer who had not previously been treated. Following randomisation of 634 patients, the open-label study was amended to include a 2 × 2 factorial randomised (partially blinded for bevacizumab) phase III trial with the coprimary objective of demonstrating superiority of bevacizumab in combination with chemotherapy compared with chemotherapy alone. Measured outcomes included overall survival, progression-free survival, response rate, adverse effects of treatment and health-related quality of life. The manufacturer’s primary pooled analysis of superiority (using the intention-to-treat population) showed that after a median follow-up of 28 months, the addition of bevacizumab to chemotherapy significantly improved progression-free survival and overall survival compared with chemotherapy alone in adult patients with histologically confirmed metastatic colorectal cancer who were not previously treated [median progression-free survival 9.4 vs 7.7 months (absolute difference 1.7 months); hazard ratio (HR) 0.79, 97.5% confidence interval (CI) 0.72 to 0.87; p = 0.0001; median overall survival 21.2 vs 18.9 months (absolute difference 2.3 months); HR 0.83, 97.5% CI 0.74 to 0.93; p = 0.0019]. The NO16966 trial was of reasonable methodological quality and demonstrated a significant improvement in both progression-free survival and overall survival when bevacizumab was added to XELOX or FOLFOX. However, the size of the actual treatment effect of bevacizumab is uncertain. The ERG believed that the modelling structure employed was appropriate, but highlighted several key issues and areas of uncertainty. At the time of writing, NICE was yet to issue the guidance for this appraisal.
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Maund E, McKenna C, Sarowar M, Fox D, Stevenson M, Pepper C, Palmer S, Woolacott N. Dronedarone for the treatment of atrial fibrillation and atrial flutter. Health Technol Assess 2010. [DOI: 10.3310/hta14suppl2-08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This paper presents a summary of the evidence review group (ERG) report on the clinical effectiveness and cost-effectiveness of dronedarone for the treatment of atrial fibrillation (AF) or atrial flutter 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 process. The population considered in the submission were adult clinically stable patients with a recent history of or current non-permanent AF. Comparators were the current available anti-arrhythmic drugs: class 1c agents (flecainide and propafenone), sotalol and amiodarone. Outcomes were AF recurrence, all-cause mortality, stroke, treatment discontinuations (due to any cause or due to adverse events) and serious adverse events. The main evidence came from four phase III randomised controlled trials, direct and indirect meta-analyses from a systematic review, and a synthesis of the direct and indirect evidence using a mixed-treatment comparison. Overall, the results from the different synthesis approaches showed that the odds of AF recurrence appeared statistically significantly lower with dronedarone and other anti-arrhythmic drugs than with non-active control, and that the odds of AF recurrence are statistically significantly higher for dronedarone than for amiodarone. However, the results for outcomes of all-cause mortality, stroke and treatment discontinuations and serious adverse events were all uncertain. A discrete event simulation model was used to evaluate dronedarone versus antiarrhythmic drugs and standard therapy alone. The incremental cost-effectiveness ratio of dronedarone was relatively robust and less than £20,000 per quality-adjusted life-year. Exploratory work undertaken by the ERG identified that the main drivers of cost-effectiveness were the benefits assigned to dronedarone for all-cause mortality and stroke. Dronedarone is not cost-effective relative to its comparators when the only effect of treatment is a reduction in AF recurrences. In conclusion, uncertainties remain in the clinical effectiveness and cost-effectiveness of dronedarone. In particular, the clinical evidence for the major drivers of cost-effectiveness (all-cause mortality and stroke), and consequently the additional benefits attributed in the economic model to dronedarone compared to other anti-arrhythmic drugs are highly uncertain. The final guidance, issued by NICE on 25 August 2010, states that: Dronedarone is recommended as an option for the treatment of non-permanent atrial fibrillation only in people: whose atrial fibrillation is not controlled by first-line therapy (usually including beta-blockers), that is, as a second-line treatment option, and who have at least one of the following cardiovascular risk factors: - hypertension requiring drugs of at least two different classes, diabetes mellitus, previous transient ischaemic attack, stroke or systemic embolism, left atrial diameter of 50 mm or greater, left ventricular ejection fraction less than 40% (noting that the summary of product characteristics [SPC] does not recommend dronedarone for people with left ventricular ejection fraction less than 35% because of limited experience of using it in this group) or age 70 years or older, and who do not have unstable New York Heart Association (NYHA) class III or IV heart failure. Furthermore, ‘People who do not meet the criteria above who are currently receiving dronedarone should have the option to continue treatment until they and their clinicians consider it appropriate to stop’.
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