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  • Associations Between Adding a Radial Artery Graft to Single and Bilateral Internal Thoracic Artery Grafts and Outcomes: Insights From the Arterial Revascularization Trial.

    2 April 2018

    BACKGROUND: Whether the use of the radial artery (RA) can improve clinical outcomes in coronary artery bypass graft surgery remains unclear. The ART (Arterial Revascularization Trial) was designed to compare survival after bilateral internal thoracic artery (BITA) over single left internal thoracic artery (SITA). In the ART, a large proportion of patients (≈20%) also received an RA graft instead of a saphenous vein graft (SVG). We aimed to investigate the associations between using the RA instead of an SVG to supplement SITA or BITA grafts and outcomes by performing a post hoc analysis of the ART. METHODS: Patients enrolled in the ART (n=3102) were classified on the basis of conduits actually received (as treated). The analysis included 2737 patients who received an RA graft (RA group; n=632) or SVG only (SVG group; n=2105) in addition to SITA or BITA grafts. The primary end point was the composite of myocardial infarction, cardiovascular death, and repeat revascularization at 5 years. Propensity score matching and stratified Cox regression were used to compare the 2 strategies. RESULTS: Myocardial infarction, cardiovascular death, and repeat revascularization cumulative incidence was 2.3% (95% confidence interval [CI], 1.1-3.4), 3.5% (95% CI, 2.1-5.0), and 4.4% (95% CI, 2.8-6.0) in the RA group and 3.4% (95% CI, 2.0-4.8), 4.0% (95% CI, 2.5-5.6), and 7.6% (95% CI, 5.5-9.7) in the SVG group, respectively. The composite end point was significantly lower in the RA group (8.8%; 95% CI, 6.5-11.0) compared with the SVG group (13.6%; 95% CI, 10.8-16.3;P=0.005). This association was present when an RA graft was used to supplement both SITA and BITA grafts (interactionP=0.62). CONCLUSIONS: This post hoc ART analysis showed that an additional RA was associated with lower risk for midterm major adverse cardiac events when used to supplement SITA or BITA grafts. CLINICAL TRIAL REGISTRATION: URL: https://www.situ.ox.ac.uk/surgical-trials/art. Unique identifier: ISRCTN46552265.

  • The design and development of a complex multifactorial falls assessment intervention for falls prevention: The Prevention of Falls Injury Trial (PreFIT).

    2 April 2018

    BACKGROUND: This paper describes the design and development of a complex multifactorial falls prevention (MFFP) intervention for implementation and testing within the framework of a large UK-based falls prevention randomised controlled trial (RCT). METHODS: A complex intervention was developed for inclusion within the Prevention of Falls Injury Trial (PreFIT), a multicentre pragmatic RCT. PreFIT aims to compare the clinical and cost-effectiveness of three alternative primary care falls prevention interventions (advice, exercise and MFFP), on outcomes of fractures and falls. Community-dwelling adults, aged 70 years and older, were recruited from primary care in the National Health Service (NHS), England. RESULTS: Development of the PreFIT MFFP intervention was informed by the existing evidence base and clinical guidelines for the assessment and management of falls in older adults. After piloting and modification, the final MFFP intervention includes seven falls risk factors: a detailed falls history interview with consideration of 'red flags'; assessment of balance and gait; vision; medication screen; cardiac screen; feet and footwear screen and home environment assessment. This complex intervention has been fully manualised with clear, documented assessment and treatment pathways for each risk factor. Each risk factor is assessed in every trial participant referred for MFFP. Referral for assessment is based upon a screening survey to identify those with a history of falling or balance problems. Intervention delivery can be adapted to the local setting. CONCLUSION: This complex falls prevention intervention is currently being tested within the framework of a large clinical trial. This paper adheres to TIDieR and CONSORT recommendations for the comprehensive and explicit reporting of trial interventions. Results from the PreFIT study will be published in due course. The effectiveness and cost-effectiveness of the PreFIT MFFP intervention, compared to advice and exercise, on the prevention of falls and fractures, will be reported at the conclusion of the trial.

  • Flaws in the application and interpretation of statistical analyses in systematic reviews of therapeutic interventions were common: a cross-sectional analysis.

    4 April 2018

    OBJECTIVES: The objective of the study was to investigate the application and interpretation of statistical analyses in a cross-section of systematic reviews (SRs) of therapeutic interventions, without restriction by journal, clinical condition, or specialty. STUDY DESIGN AND SETTING: We evaluated a random sample of SRs assembled previously, which were indexed in MEDLINE® during February 2014, focused on a treatment or prevention question, and reported at least one meta-analysis. The reported statistical methods used in each SR were extracted from articles and online appendices by one author, with a 20% random sample extracted in duplicate. RESULTS: We evaluated 110 SRs; 78/110 (71%) were non-Cochrane SRs and 55/110 (50%) investigated a pharmacological intervention. The SRs presented a median of 13 (interquartile range: 5-27) meta-analytic effects. When considering the index (primary or first reported) meta-analysis of each SR, just over half (62/110 [56%]) used the random-effects model, but few (5/62 [8%]) interpreted the meta-analytic effect correctly (as the average of the intervention effects across all studies). A statistical test for funnel plot asymmetry was reported in 17/110 (15%) SRs; however, in only 4/17 (24%) did the test include the recommended number of at least 10 studies of varying size. Subgroup analyses accompanied 42/110 (38%) index meta-analyses, but findings were not interpreted with respect to a test for interaction in 29/42 (69%) cases, and the issue of potential confounding in the subgroup analyses was not raised in any SR. CONCLUSIONS: There is scope for improvement in the application and interpretation of statistical analyses in SRs of therapeutic interventions. The involvement of statisticians on the SR team and establishment of partnerships between researchers with specialist expertise in SR methods and journal editors may help overcome these shortcomings.

  • Maximising value from a United Kingdom Biomedical Research Centre: study protocol.

    5 April 2018

    BACKGROUND: Biomedical Research Centres (BRCs) are partnerships between healthcare organisations and universities in England. Their mission is to generate novel treatments, technologies, diagnostics and other interventions that increase the country's international competitiveness, to rapidly translate these innovations into benefits for patients, and to improve efficiency and reduce waste in healthcare. As NIHR Oxford BRC (Oxford BRC) enters its third 5-year funding period, we seek to (1) apply the evidence base on how best to support the various partnerships in this large, multi-stakeholder research system and (2) research how these partnerships play out in a new, ambitious programme of translational research. METHODS: Organisational case study, informed by the principles of action research. A cross-cutting theme, 'Partnerships for Health, Wealth and Innovation' has been established with multiple sub-themes (drug development, device development, business support and commercialisation, research methodology and statistics, health economics, bioethics, patient and public involvement and engagement, knowledge translation, and education and training) to support individual BRC research themes and generate cross-theme learning. The 'Partnerships' theme will support the BRC's goals by facilitating six types of partnership (with patients and citizens, clinical services, industry, across the NIHR infrastructure, across academic disciplines, and with policymakers and payers) through a range of engagement platforms and activities. We will develop a longitudinal progress narrative centred around exemplar case studies, and apply theoretical models from innovation studies (Triple Helix), sociology of science (Mode 2 knowledge production) and business studies (Value Co-creation). Data sources will be the empirical research studies within individual BRC research themes (who will apply separately for NHS ethics approval), plus documentary analysis and interviews and ethnography with research stakeholders. This study has received ethics clearance through the University of Oxford Central University Research Ethics Committee. DISCUSSION: We anticipate that this work will add significant value to Oxford BRC. We predict accelerated knowledge translation; closer alignment of the innovation process with patient priorities and the principles of responsible, ethical research; reduction in research waste; new knowledge about the governance and activities of multi-stakeholder research partnerships and the contexts in which they operate; and capacity-building that reflects the future needs of a rapidly-evolving health research system.

  • Desmopressin use for minimising perioperative blood transfusion.

    16 March 2018

    BACKGROUND: Blood transfusion is administered during many types of surgery, but its efficacy and safety are increasingly questioned. Evaluation of the efficacy of agents, such as desmopressin (DDAVP; 1-deamino-8-D-arginine-vasopressin), that may reduce perioperative blood loss is needed. OBJECTIVES: To examine the evidence for the efficacy of DDAVP in reducing perioperative blood loss and the need for red cell transfusion in people who do not have inherited bleeding disorders. SEARCH METHODS: We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (2017, issue 3) in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (from 1937), the Transfusion Evidence Library (from 1980), and ongoing trial databases (all searches to 3 April 2017). SELECTION CRITERIA: We included randomised controlled trials comparing DDAVP to placebo or an active comparator (e.g. tranexamic acid, aprotinin) before, during, or immediately after surgery or after invasive procedures in adults or children. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. MAIN RESULTS: We identified 65 completed trials (3874 participants) and four ongoing trials. Of the 65 completed trials, 39 focused on adult cardiac surgery, three on paediatric cardiac surgery, 12 on orthopaedic surgery, two on plastic surgery, and two on vascular surgery; seven studies were conducted in surgery for other conditions. These trials were conducted between 1986 and 2016, and 11 were funded by pharmaceutical companies or by a party with a commercial interest in the outcome of the trial.The GRADE quality of evidence was very low to moderate across all outcomes. No trial reported quality of life. DDAVP versus placebo or no treatmentTrial results showed considerable heterogeneity between surgical settings for total volume of red cells transfused (low-quality evidence) and for total blood loss (very low-quality evidence) due to large differences in baseline blood loss. Consequently, these outcomes were not pooled and were reported in subgroups.Compared with placebo, DDAVP may slightly decrease the total volume of red cells transfused in adult cardiac surgery (mean difference (MD) -0.52 units, 95% confidence interval (CI) -0.96 to -0.08 units; 14 trials, 957 participants), but may lead to little or no difference in orthopaedic surgery (MD -0.02, 95% CI -0.67 to 0.64 units; 6 trials, 303 participants), vascular surgery (MD 0.06, 95% CI -0.60 to 0.73 units; 2 trials, 135 participants), or hepatic surgery (MD -0.47, 95% CI -1.27 to 0.33 units; 1 trial, 59 participants).DDAVP probably leads to little or no difference in the total number of participants transfused with blood (risk ratio (RR) 0.96, 95% CI 0.86 to 1.06; 25 trials; 1806 participants) (moderate-quality evidence).Whether DDAVP decreases total blood loss in adult cardiac surgery (MD -135.24 mL, 95% CI -210.80 mL to -59.68 mL; 22 trials, 1358 participants), orthopaedic surgery (MD -285.76 mL, 95% CI -514.99 mL to -56.53 mL; 5 trials, 241 participants), or vascular surgery (MD -582.00 mL, 95% CI -1264.07 mL to 100.07 mL; 1 trial, 44 participants) is uncertain because the quality of evidence is very low.DDAVP probably leads to little or no difference in all-cause mortality (Peto odds ratio (pOR) 1.09, 95% CI 0.51 to 2.34; 22 trials, 1631 participants) or in thrombotic events (pOR 1.36, 95% CI, 0.85 to 2.16; 29 trials, 1984 participants) (both low-quality evidence). DDAVP versus placebo or no treatment for people with platelet dysfunctionCompared with placebo, DDAVP may lead to a reduction in the total volume of red cells transfused (MD -0.65 units, 95% CI -1.16 to -0.13 units; 6 trials, 388 participants) (low-quality evidence) and in total blood loss (MD -253.93 mL, 95% CI -408.01 mL to -99.85 mL; 7 trials, 422 participants) (low-quality evidence).DDAVP probably leads to little or no difference in the total number of participants receiving a red cell transfusion (RR 0.83, 95% CI 0.66 to 1.04; 5 trials, 258 participants) (moderate-quality evidence).Whether DDAVP leads to a difference in all-cause mortality (pOR 0.72, 95% CI 0.12 to 4.22; 7 trials; 422 participants) or in thrombotic events (pOR 1.58, 95% CI 0.60 to 4.17; 7 trials, 422 participants) is uncertain because the quality of evidence is very low. DDAVP versus tranexamic acidCompared with tranexamic acid, DDAVP may increase the volume of blood transfused (MD 0.6 units, 95% CI 0.09 to 1.11 units; 1 trial, 40 participants) and total blood loss (MD 142.81 mL, 95% CI 79.78 mL to 205.84 mL; 2 trials, 115 participants) (both low-quality evidence).Whether DDAVP increases or decreases the total number of participants transfused with blood is uncertain because the quality of evidence is very low (RR 2.42, 95% CI 1.04 to 5.64; 3 trials, 135 participants).No trial reported all-cause mortality.Whether DDAVP leads to a difference in thrombotic events is uncertain because the quality of evidence is very low (pOR 2.92, 95% CI 0.32 to 26.83; 2 trials, 115 participants). DDAVP versus aprotininCompared with aprotinin, DDAVP probably increases the total number of participants transfused with blood (RR 2.41, 95% CI 1.45 to 4.02; 1 trial, 99 participants) (moderate-quality evidence).No trials reported volume of blood transfused or total blood loss and the single trial that included mortality as an outcome reported no deaths.Whether DDAVP leads to a difference in thrombotic events is uncertain because the quality of evidence is very low (pOR 0.98, 95% CI 0.06 to 15.89; 2 trials, 152 participants). AUTHORS' CONCLUSIONS: Most of the evidence derived by comparing DDAVP versus placebo was obtained in cardiac surgery, where DDAVP was administered after cardiopulmonary bypass. In adults undergoing cardiac surgery, the reduction in volume of red cells transfused and total blood loss was small and was unlikely to be clinically important. It is less clear whether DDAVP may be of benefit for children and for those undergoing non-cardiac surgery. A key area for researchers is examining the effects of DDAVP for people with platelet dysfunction. Few trials have compared DDAVP versus tranexamic acid or aprotinin; consequently, we are uncertain of the relative efficacy of these interventions.