Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Barnaby C Reeves is active.

Publication


Featured researches published by Barnaby C Reeves.


Circulation | 2007

Increased Mortality, Postoperative Morbidity, and Cost After Red Blood Cell Transfusion in Patients Having Cardiac Surgery

Gavin J. Murphy; Barnaby C Reeves; Chris A. Rogers; Syed I.A. Rizvi; Lucy Culliford; Gianni D. Angelini

Background— Red blood cell transfusion can both benefit and harm. To inform decisions about transfusion, we aimed to quantify associations of transfusion with clinical outcomes and cost in patients having cardiac surgery. Methods and Results— Clinical, hematology, and blood transfusion databases were linked with the UK population register. Additional hematocrit information was obtained from intensive care unit charts. Composite infection (respiratory or wound infection or septicemia) and ischemic outcomes (myocardial infarction, stroke, renal impairment, or failure) were prespecified as coprimary end points. Secondary outcomes were resource use, cost, and survival. Associations were estimated by regression modeling with adjustment for potential confounding. All adult patients having cardiac surgery between April 1, 1996, and December 31, 2003, with key exposure and outcome data were included (98%). Adjusted odds ratios for composite infection (737 of 8516) and ischemic outcomes (832 of 8518) for transfused versus nontransfused patients were 3.38 (95% confidence interval [CI], 2.60 to 4.40) and 3.35 (95% CI, 2.68 to 4.35), respectively. Transfusion was associated with increased relative cost of admission (any transfusion, 1.42 times [95% CI, 1.37 to 1.46], varying from 1.11 for 1 U to 3.35 for >9 U). At any time after their operations, transfused patients were less likely to have been discharged from hospital (hazard ratio [HR], 0.63; 95% CI, 0.60 to 0.67) and were more likely to have died (0 to 30 days: HR, 6.69; 95% CI, 3.66 to 15.1; 31 days to 1 year: HR, 2.59; 95% CI, 1.68 to 4.17; >1 year: HR, 1.32; 95% CI, 1.08 to 1.64). Conclusions— Red blood cell transfusion in patients having cardiac surgery is strongly associated with both infection and ischemic postoperative morbidity, hospital stay, increased early and late mortality, and hospital costs.


Ophthalmology | 2012

Ranibizumab versus Bevacizumab to Treat Neovascular Age-related Macular Degeneration: One-Year Findings from the IVAN Randomized Trial.

Usha Chakravarthy; Simon P. Harding; Chris A. Rogers; Susan M. Downes; Andrew J. Lotery; Sarah Wordsworth; Barnaby C Reeves

PURPOSE To compare the efficacy and safety of ranibizumab and bevacizumab intravitreal injections to treat neovascular age-related macular degeneration (nAMD). DESIGN Multicenter, noninferiority factorial trial with equal allocation to groups. The noninferiority limit was 3.5 letters. This trial is registered (ISRCTN92166560). PARTICIPANTS People >50 years of age with untreated nAMD in the study eye who read ≥ 25 letters on the Early Treatment Diabetic Retinopathy Study chart. METHODS We randomized participants to 4 groups: ranibizumab or bevacizumab, given either every month (continuous) or as needed (discontinuous), with monthly review. MAIN OUTCOME MEASURES The primary outcome is at 2 years; this paper reports a prespecified interim analysis at 1 year. The primary efficacy and safety outcome measures are distance visual acuity and arteriothrombotic events or heart failure. Other outcome measures are health-related quality of life, contrast sensitivity, near visual acuity, reading index, lesion morphology, serum vascular endothelial growth factor (VEGF) levels, and costs. RESULTS Between March 27, 2008 and October 15, 2010, we randomized and treated 610 participants. One year after randomization, the comparison between bevacizumab and ranibizumab was inconclusive (bevacizumab minus ranibizumab -1.99 letters, 95% confidence interval [CI], -4.04 to 0.06). Discontinuous treatment was equivalent to continuous treatment (discontinuous minus continuous -0.35 letters; 95% CI, -2.40 to 1.70). Foveal total thickness did not differ by drug, but was 9% less with continuous treatment (geometric mean ratio [GMR], 0.91; 95% CI, 0.86 to 0.97; P = 0.005). Fewer participants receiving bevacizumab had an arteriothrombotic event or heart failure (odds ratio [OR], 0.23; 95% CI, 0.05 to 1.07; P = 0.03). There was no difference between drugs in the proportion experiencing a serious systemic adverse event (OR, 1.35; 95% CI, 0.80 to 2.27; P = 0.25). Serum VEGF was lower with bevacizumab (GMR, 0.47; 95% CI, 0.41 to 0.54; P<0.0001) and higher with discontinuous treatment (GMR, 1.23; 95% CI, 1.07 to 1.42; P = 0.004). Continuous and discontinuous treatment costs were £9656 and £6398 per patient per year for ranibizumab and £1654 and £1509 for bevacizumab; bevacizumab was less costly for both treatment regimens (P<0.0001). CONCLUSIONS The comparison of visual acuity at 1 year between bevacizumab and ranibizumab was inconclusive. Visual acuities with continuous and discontinuous treatment were equivalent. Other outcomes are consistent with the drugs and treatment regimens having similar efficacy and safety. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosures may be found after the references.


BMJ | 2016

ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions

Jonathan A C Sterne; Miguel A. Hernán; Barnaby C Reeves; Jelena Savovic; Nancy D Berkman; Meera Viswanathan; David Henry; Douglas G. Altman; Mohammed T Ansari; Isabelle Boutron; James Carpenter; An-Wen Chan; Rachel Churchill; Jonathan J Deeks; Asbjørn Hróbjartsson; Jamie Kirkham; Peter Jüni; Yoon K. Loke; Theresa D Pigott; Craig Ramsay; Deborah Regidor; Hannah R. Rothstein; Lakhbir Sandhu; Pasqualina Santaguida; Holger J. Schunemann; B. Shea; Ian Shrier; Peter Tugwell; Lucy Turner; Jeffrey C. Valentine

Non-randomised studies of the effects of interventions are critical to many areas of healthcare evaluation, but their results may be biased. It is therefore important to understand and appraise their strengths and weaknesses. We developed ROBINS-I (“Risk Of Bias In Non-randomised Studies - of Interventions”), a new tool for evaluating risk of bias in estimates of the comparative effectiveness (harm or benefit) of interventions from studies that did not use randomisation to allocate units (individuals or clusters of individuals) to comparison groups. The tool will be particularly useful to those undertaking systematic reviews that include non-randomised studies.


The Lancet | 2013

Alternative treatments to inhibit VEGF in age-related choroidal neovascularisation: 2-year findings of the IVAN randomised controlled trial

Usha Chakravarthy; Simon P. Harding; Chris A. Rogers; Susan M. Downes; Andrew J. Lotery; Lucy Culliford; Barnaby C Reeves

BACKGROUND Bevacizumab has been suggested to have similar effectiveness to ranibizumab for treatment of neovascular age-related macular degeneration. The Inhibition of VEGF in Age-related choroidal Neovascularisation (IVAN) trial was designed to compare these drugs and different regimens. Here, we report the findings at the prespecified 2-year timepoint. METHODS In a multicentre, 2×2 factorial, non-inferiority randomised trial, we enrolled adults aged at least 50 years with active, previously untreated neovascular age-related macular degeneration and a best corrected distance visual acuity (BCVA) of at least 25 letters from 23 hospitals in the UK. Participants were randomly assigned (1:1:1:1) to intravitreal injections of ranibizumab (0·5 mg) or bevacizumab (1·25 mg) in continuous (every month) or discontinuous (as needed) regimens, with monthly review. Study participants and clinical assessors were masked to drug allocation. Allocation to continuous or discontinuous treatment was masked up to 3 months, at which point investigators and participants were unmasked. The primary outcome was BCVA at 2 years, with a prespecified non-inferiority limit of 3·5 letters. The primary safety outcome was arterial thrombotic event or hospital admission for heart failure. Analyses were by modified intention to treat. This trial is registered, number ISRCTN92166560. FINDINGS Between March 27, 2008, and Oct 15, 2010, 628 patients underwent randomisation. 18 were withdrawn; 610 received study drugs (314 ranibizumab; 296 bevacizumab) and were included in analyses. 525 participants reached the visit at 2 years: 134 ranibizumab in continuous regimen, 137 ranibizumab in discontinuous regimen, 127 bevacizumab in continuous regimen, and 127 bevacizumab in discontinuous regimen. For BCVA, bevacizumab was neither non-inferior nor inferior to ranibizumab (mean difference -1·37 letters, 95% CI -3·75 to 1·01; p=0·26). Discontinuous treatment was neither non-inferior nor inferior to continuous treatment (-1·63 letters, -4·01 to 0·75; p=0·18). Frequency of arterial thrombotic events or hospital admission for heart failure did not differ between groups given ranibizumab (20 [6%] of 314 participants) and bevacizumab (12 [4%] of 296; odds ratio [OR] 1·69, 95% CI 0·80-3·57; p=0·16), or those given continuous (12 [4%] of 308) and discontinuous treatment (20 [7%] of 302; 0·56, 0·27-1·19; p=0·13). Mortality was lower with continuous than discontinuous treatment (OR 0·47, 95% CI 0·22-1·03; p=0·05), but did not differ by drug group (0·96, 0·46-2·02; p=0·91). INTERPRETATION Ranibizumab and bevacizumab have similar efficacy. Reduction in the frequency of retreatment resulted in a small loss of efficacy irrespective of drug. Safety was worse when treatment was administered discontinuously. These findings highlight that the choice of anti-VEGF treatment strategy is less straightforward than previously thought. FUNDING UK National Institute for Health Research Health Technology Assessment programme.


Journal of Epidemiology and Community Health | 2012

Using natural experiments to evaluate population health interventions: new Medical Research Council guidance

Peter Craig; C Cooper; David Gunnell; Sally Haw; Kenny D Lawson; Sally Macintyre; David Ogilvie; Mark Petticrew; Barnaby C Reeves; Matt Sutton; Simon G. Thompson

Natural experimental studies are often recommended as a way of understanding the health impact of policies and other large scale interventions. Although they have certain advantages over planned experiments, and may be the only option when it is impossible to manipulate exposure to the intervention, natural experimental studies are more susceptible to bias. This paper introduces new guidance from the Medical Research Council to help researchers and users, funders and publishers of research evidence make the best use of natural experimental approaches to evaluating population health interventions. The guidance emphasises that natural experiments can provide convincing evidence of impact even when effects are small or take time to appear. However, a good understanding is needed of the process determining exposure to the intervention, and careful choice and combination of methods, testing of assumptions and transparent reporting is vital. More could be learnt from natural experiments in future as experience of promising but lesser used methods accumulates.


The New England Journal of Medicine | 2015

Liberal or Restrictive Transfusion after Cardiac Surgery

Gavin J. Murphy; Katie Pike; Chris A. Rogers; Sarah Wordsworth; Elizabeth A. Stokes; Gianni D. Angelini; Barnaby C Reeves

BACKGROUND Whether a restrictive threshold for hemoglobin level in red-cell transfusions, as compared with a liberal threshold, reduces postoperative morbidity and health care costs after cardiac surgery is uncertain. METHODS We conducted a multicenter, parallel-group trial in which patients older than 16 years of age who were undergoing nonemergency cardiac surgery were recruited from 17 centers in the United Kingdom. Patients with a postoperative hemoglobin level of less than 9 g per deciliter were randomly assigned to a restrictive transfusion threshold (hemoglobin level <7.5 g per deciliter) or a liberal transfusion threshold (hemoglobin level <9 g per deciliter). The primary outcome was a serious infection (sepsis or wound infection) or an ischemic event (permanent stroke [confirmation on brain imaging and deficit in motor, sensory, or coordination functions], myocardial infarction, infarction of the gut, or acute kidney injury) within 3 months after randomization. Health care costs, excluding the index surgery, were estimated from the day of surgery to 3 months after surgery. RESULTS A total of 2007 patients underwent randomization; 4 participants withdrew, leaving 1000 in the restrictive-threshold group and 1003 in the liberal-threshold group. Transfusion rates after randomization were 53.4% and 92.2% in the two groups, respectively. The primary outcome occurred in 35.1% of the patients in the restrictive-threshold group and 33.0% of the patients in the liberal-threshold group (odds ratio, 1.11; 95% confidence interval [CI], 0.91 to 1.34; P=0.30); there was no indication of heterogeneity according to subgroup. There were more deaths in the restrictive-threshold group than in the liberal-threshold group (4.2% vs. 2.6%; hazard ratio, 1.64; 95% CI, 1.00 to 2.67; P=0.045). Serious postoperative complications, excluding primary-outcome events, occurred in 35.7% of participants in the restrictive-threshold group and 34.2% of participants in the liberal-threshold group. Total costs did not differ significantly between the groups. CONCLUSIONS A restrictive transfusion threshold after cardiac surgery was not superior to a liberal threshold with respect to morbidity or health care costs. (Funded by the National Institute for Health Research Health Technology Assessment program; Current Controlled Trials number, ISRCTN70923932.).


Journal of Clinical Epidemiology | 2016

ROBIS: A new tool to assess risk of bias in systematic reviews was developed

Penny F Whiting; Jelena Savovic; Julian P. T. Higgins; Deborah M Caldwell; Barnaby C Reeves; Beverley Shea; Philippa Davies; Jos Kleijnen; Rachel Churchill

Objective To develop ROBIS, a new tool for assessing the risk of bias in systematic reviews (rather than in primary studies). Study Design and Setting We used four-stage approach to develop ROBIS: define the scope, review the evidence base, hold a face-to-face meeting, and refine the tool through piloting. Results ROBIS is currently aimed at four broad categories of reviews mainly within health care settings: interventions, diagnosis, prognosis, and etiology. The target audience of ROBIS is primarily guideline developers, authors of overviews of systematic reviews (“reviews of reviews”), and review authors who might want to assess or avoid risk of bias in their reviews. The tool is completed in three phases: (1) assess relevance (optional), (2) identify concerns with the review process, and (3) judge risk of bias. Phase 2 covers four domains through which bias may be introduced into a systematic review: study eligibility criteria; identification and selection of studies; data collection and study appraisal; and synthesis and findings. Phase 3 assesses the overall risk of bias in the interpretation of review findings and whether this considered limitations identified in any of the phase 2 domains. Signaling questions are included to help judge concerns with the review process (phase 2) and the overall risk of bias in the review (phase 3); these questions flag aspects of review design related to the potential for bias and aim to help assessors judge risk of bias in the review process, results, and conclusions. Conclusions ROBIS is the first rigorously developed tool designed specifically to assess the risk of bias in systematic reviews.


BMJ | 1998

Point of care testing: randomised controlled trial of clinical outcome

Jason M Kendall; Barnaby C Reeves; Mike Clancy

Abstract Objectives: To describe the proportion of patients attending an accident and emergency department for whom blood analysis at the point of care brought about a change in management; to measure the extent to which point of care testing resulted in differences in clinical outcome for these patients when compared with patients whose samples were tested by the hospital laboratory. Design: Open, single centre, randomised controlled trial. Blood samples were randomly allocated to point of care testing or testing by the hospitals central laboratory. Setting: The accident and emergency department of the Bristol Royal Infirmary, a large teaching hospital which cares for an inner city population. Subjects: Representative sample of patients who attended the department between April 1996 and April 1997 and who required blood tests. Data collection was structured in 8 hour blocks so that all hours of the day and all days of the week were equally represented. Main outcome measures: The proportion of patients for whom point of care testing brought about a change in treatment in which timing was considered to be critical to clinical outcome. Mortality, the length of stay in hospital, admission rate, the amount of time spent waiting for results of blood tests, the amount of time taken to decide on management plans, and the amount of time patients spent in the department were compared between patients whose samples were tested at the point of care and those whose samples were sent to the laboratory. Results: Samples were obtained from 1728 patients. Changes in management in which timing was considered to be critical occurred in 59 out of 859 (6.9%, 95% confidence interval 5.3% to 8.8%) patients in the point of care arm of the trial. Decisions were made 74 minutes earlier (68 min to 80 min, P<0.0001) when point of care testing was used for haematological tests as compared to central laboratory testing, 86 minutes earlier (80 min to 92 min, P<0.0001) for biochemical tests, and 21 minutes earlier (−3 min to 44 min, P=0.09) for analyses of arterial blood gases. There were no differences between the groups in the amount of time spent in the department, length of stay in hospital, admission rates, or mortality. Conclusion: Point of care testing reduced the time taken to make decisions on patient management that were dependent on the results of blood tests. It also brought about faster changes in treatment for which timing was considered to be critical in about 7% of patients. These changes did not affect clinical outcome or the amount of time patients spent in the department. Key messages Point of care testing reduced the amount of time doctors spent waiting for results of blood tests when compared to the time spent waiting for results from the hospital laboratory in an accident and emergency department The time taken to decide on a management plan was also reduced as a result of the shorter time spent waiting for results of point of care tests About 7% of patients who needed urgent blood testing had changes in treatment in which timing was considered to be critical when point of care testing was used Patients did not spend less time in the accident and emergency department even when test results were available more quickly and patient management decisions were made more quickly. This suggests that the availability of test results is not the factor which slows down the arrangement of further care Improvements in process, such as a reduction in the time doctors wait for test results and the ability to make clinical decisions more quickly, do not seem to improve clinical outcome in this sample of patients


BMJ | 2005

Challenges to implementing the national programme for information technology (NPfIT) : a qualitative study

Jane Hendy; Barnaby C Reeves; Naomi Fulop; Andrew Hutchings; Cristina Masseria

Abstract Objectives To describe the context for implementing the national programme for information technology (NPfIT) in England, actual and perceived barriers, and opportunities to facilitate implementation. Design Case studies and in depth interviews, with themes identified using a framework developed from grounded theory. Setting Four acute NHS trusts in England. Participants Senior trust managers and clinicians, including chief executives, directors of information technology, medical directors, and directors of nursing. Results The trusts varied in their circumstances, which may affect their ability to implement the NPfIT. The process of implementation has been suboptimal, leading to reports of low morale by the NHS staff responsible for implementation. The overall timetable is unrealistic, and trusts are uncertain about their implementation schedules. Short term benefits alone are unlikely to persuade NHS staff to adopt the national programme enthusiastically, and some may experience a loss of electronic functionality in the short term. Conclusions: The sociocultural challenges to implementing the NPfIT are as daunting as the technical and logistical ones. Senior NHS staff feel these have been neglected. We recommend that national programme managers prioritise strategies to improve communication with, and to gain the cooperation of, front line staff.


The Journal of Thoracic and Cardiovascular Surgery | 2009

Effects of on- and off-pump coronary artery surgery on graft patency, survival, and health-related quality of life: long-term follow-up of 2 randomized controlled trials.

Gianni D. Angelini; Lucy Culliford; David K. Smith; Mark Hamilton; Gavin J. Murphy; Raimondo Ascione; Andreas Baumbach; Barnaby C Reeves

OBJECTIVE Off-pump coronary artery bypass grafting reduces postoperative morbidity and uses fewer resources than conventional surgical intervention with cardiopulmonary bypass. However, only 15% to 20% of coronary artery bypass grafting operations use off-pump coronary artery bypass. One reason for not using off-pump coronary artery bypass might be the surgeons concern about the long-term patency of grafts performed with this technique. Therefore our objective was to compare long-term outcomes in patients randomized to off-pump coronary artery bypass or coronary artery bypass grafting with cardiopulmonary bypass. METHODS Participants in 2 randomized trials comparing off-pump coronary artery bypass and coronary artery bypass grafting with cardiopulmonary bypass were followed up for 6 to 8 years after surgical intervention to assess graft patency, major adverse cardiac-related events, and health-related quality of life. Patency was assessed by using multidetector computed tomographic coronary angiographic analysis with a 16-slice scanner. Two blinded observers classified proximal, body, and distal segments of each graft as occluded or not. Major adverse cardiac-related events and health-related quality of life were obtained from questionnaires given to participants and family practitioners. RESULTS Patency was studied in 199 and health-related quality of life was studied in 299 of 349 survivors. There was no evidence of attrition bias. The likelihood of graft occlusion was no different between off-pump coronary artery bypass (10.6%) and coronary artery bypass grafting with cardiopulmonary bypass (11.0%) groups (odds ratio, 1.00; 95% confidence interval, 0.55-1.81; P > .99). Graft occlusion was more likely at the distal than the proximal anastomosis (odds ratio, 1.11; 95% confidence interval, 1.02-1.20). There were also no differences between the off-pump coronary artery bypass and coronary artery bypass grafting with cardiopulmonary bypass groups in the hazard of death (hazard ratio, 1.24; 95% confidence interval, 0.72-2.15) or major adverse cardiac-related events or death (hazard ratio, 0.84; 95% confidence interval, 0.58-1.24), or mean health-related quality of life across a range of domains and instruments. CONCLUSIONS Long-term health outcomes with off-pump coronary artery bypass are similar to those with coronary artery bypass grafting with cardiopulmonary bypass when both operations are performed by experienced surgeons.

Collaboration


Dive into the Barnaby C Reeves's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Usha Chakravarthy

Queen's University Belfast

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge