320 research outputs found

    Statistical Appraisal of 6 Recent Clinical Trials in Cardiology: JACC State-of-the-Art Review.

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    In the past 12 months, many important new clinical trials in cardiology have had their first conference presentation and publication. This paper presents a constructive critical appraisal of 6 key studies. In time order of first presentation, they are CABANA, ATTR-ACT, COAPT, DECLARE, REDUCE-IT, and AUGUSTUS. For each study, the aim herein is to document and interpret the main findings, paying attention to new findings, their research context, and study limitations. These topical examples also provide methodological insights pertinent to future clinical trials research

    Identification of Novel Pesticides for Use against Glasshouse Invertebrate Pests in UK Tomatoes and Peppers

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    To inform current and future pesticide availability to glasshouse vegetable growers, the current project trialled more than twenty products, including existing industry standards, against four key pests of glasshouse tomatoes and bell peppers. These included experimental conventional chemical pesticides as well as alternative biopesticide and biorational products based on phytochemicals, microbials and physically-acting substances. The results suggest that certain biopesticide products, particularly botanicals, provide good levels of pest control, with the same being true of experimental conventional chemical pesticides not yet recommended for use against these pests on these crops. Efforts are on-going to ensure that results of the current project translate to industry benefit via new pesticide approvals

    The role of general practice in surgical trials.

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    Critical Appraisal of the 2018 ACC Scientific Sessions Late-Breaking Trials From a Statistician's Perspective.

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    The late-breaking clinical trials presentations at the American College of Cardiology Scientific Sessions in March 2018 are an important contribution to the field of cardiology. This paper presents a constructive critical appraisal of 7 key studies: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab), VEST (Vest Prevention of Early Sudden Death Trial), SECURE-PCI (Statins Evaluation in Coronary Procedures and Revascularization), TREAT (Ticagrelor in Patients with ST-Elevation Myocardial Infarction treated with Pharmacological Thrombolysis), POISE (PeriOperative ISchemic Evaluation), SMART-DATE (Safety of 6-Month Duration of Dual Antiplatelet Therapy After Percutaneous Coronary Intervention in Patients With Acute Coronary Syndrome), and CVD-REAL 2 (Comparative Effectiveness of Cardiovascular Outcomes in New Users of SGLT-2 Inhibitors). For each study, our aim is to document and interpret the main findings, noting particularly when "positive spin" appears to occur, and to provide a balanced account of each study, paying attention to both constructive new findings and study limitations. These topical examples also provide useful general insights on what to look for when critiquing clinical trial presentations and publications

    Seafloor sediment thickness beneath the VoiLA broad-band ocean-bottom seismometer deployment in the Lesser Antilles from P-to-S delay times

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    Broad-band ocean-bottom seismometer (OBS) deployments present an opportunity to investigate the seafloor sediment thickness, which is important for constraining sediment deposition, and is also useful for subsequent seismological analyses. The Volatile Recycling in the Lesser Antilles (VoiLA) project deployed 34 OBSs over the island arc, fore- and backarc of the Lesser Antilles subduction zone for 15 months from 2016 to 2017. Using the amplitudes and delay times of P-to-S (Ps) scattered waves from the conversion of teleseismic earthquake Pwaves at the crust–sediment boundary and pre-existing relationships developed for Cascadia, we estimate sediment thickness beneath each OBS. The delay times of the Ps phases vary from 0.20 ± 0.06 to 3.55 ± 0.70 s, generally increasing from north to south. Using a single-sediment and single-crystalline crust earth model in each case, we satisfactorily model the observations of eight OBSs. At these stations we find sediment thicknesses range from 0.43 ± 0.45 to 5.49 ± 3.23 km. To match the observations of nine other OBSs, layered sediment and variable thickness crust is required in the earth model to account for wave interference effects on the observed arrivals. We perform an inversion with a two-layer sediment and a single-layer crystalline crust in these locations finding overall sediment thicknesses of 1.75 km (confidence region: 1.45–2.02 km) to 7.93 km (confidence region: 6.32–11.05 km), generally thinner than the initial estimates based on the pre-existing relationships. We find agreement between our modelled velocity structure and the velocity structure determined from the VoiLA active-source seismic refraction experiment at the three common locations. Using the Ps values and estimates from the VoiLA refraction experiment, we provide an adjusted relationship between delay time and sediment equations for the Lesser Antilles. Our new relationship is H=1.42dt1.44^{1.44} , where H is sediment thickness in kilometres and dt is mean observed Ps delay time in seconds, which may be of use in other subduction zone settings with thick seafloor sediments

    Seafloor sediment thickness beneath the VoiLA broad-band ocean-bottom seismometer deployment in the Lesser Antilles from P-to-S delay times

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    Broad-band ocean-bottom seismometer (OBS) deployments present an opportunity to investigate the seafloor sediment thickness, which is important for constraining sediment deposition, and is also useful for subsequent seismological analyses. The Volatile Recycling in the Lesser Antilles (VoiLA) project deployed 34 OBSs over the island arc, fore- and backarc of the Lesser Antilles subduction zone for 15 months from 2016 to 2017. Using the amplitudes and delay times of P-to-S (Ps) scattered waves from the conversion of teleseismic earthquake Pwaves at the crust–sediment boundary and pre-existing relationships developed for Cascadia, we estimate sediment thickness beneath each OBS. The delay times of the Ps phases vary from 0.20 ± 0.06 to 3.55 ± 0.70 s, generally increasing from north to south. Using a single-sediment and single-crystalline crust earth model in each case, we satisfactorily model the observations of eight OBSs. At these stations we find sediment thicknesses range from 0.43 ± 0.45 to 5.49 ± 3.23 km. To match the observations of nine other OBSs, layered sediment and variable thickness crust is required in the earth model to account for wave interference effects on the observed arrivals. We perform an inversion with a two-layer sediment and a single-layer crystalline crust in these locations finding overall sediment thicknesses of 1.75 km (confidence region: 1.45–2.02 km) to 7.93 km (confidence region: 6.32–11.05 km), generally thinner than the initial estimates based on the pre-existing relationships. We find agreement between our modelled velocity structure and the velocity structure determined from the VoiLA active-source seismic refraction experiment at the three common locations. Using the Ps values and estimates from the VoiLA refraction experiment, we provide an adjusted relationship between delay time and sediment equations for the Lesser Antilles. Our new relationship is H=1.42dt1.44^{1.44} , where H is sediment thickness in kilometres and dt is mean observed Ps delay time in seconds, which may be of use in other subduction zone settings with thick seafloor sediments

    PREVENTT: preoperative intravenous iron to treat anaemia in major surgery: study protocol for a randomised controlled trial.

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    BACKGROUND: Anaemia is common in patients undergoing major surgery. The current standard of care for patients with low haemoglobin in the peri-operative period is blood transfusion. The presence of preoperative anaemia is associated with an increased likelihood of the patient receiving peri-operative transfusion and worsened outcomes following surgery, more post-operative complications, delayed recovery and greater length of hospital stay. Intravenous iron, if applied in the preoperative setting, may correct anaemia by the time of surgery and reduce the need for blood transfusion and improve outcomes. METHODS/DESIGN: PREVENTT is a phase III double-blind randomised controlled trial that will compare the use of intravenous ferric carboxymaltose (dose 1000 mg) with placebo 10-42 days before major open abdominal surgery in 500 patients with anaemia (haemoglobin < 120 g/L). The primary outcome measure will be the need for blood transfusion and secondary endpoints will include post-operative recovery, length of hospital stay, health care utilisation and cost analysis. TRIAL REGISTRATION: ISRCTN67322816--registered 9 October 2012. ClinicalTrials.gov identifier: NCT01692418

    Development and evaluation of the Andhra Pradesh Children and Parent Study Physical Activity Questionnaire (APCAPS-PAQ): a cross-sectional study.

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    BACKGROUND: There is limited availability of context-specific physical activity questionnaires in low and middle income countries. The aim of this study was to develop and examine the validity of a new Indian physical activity questionnaire, the Andhra Pradesh Children and Parent Study Physical Activity Questionnaire (APCAPS-PAQ). METHODS: The current study was conducted with the cohort from the Hyderabad DXA Study (n = 2321), recruited in 2009-2010. Criterion validity (n = 245) was examined by comparing the APCAPS-PAQ to a combined heart rate and motion sensor worn for 8 days. Construct validity (n = 2321) was assessed with linear regression, comparing APCAPS-PAQ against BMI, percent body fat, and pulse rate. RESULTS: The APCAPS-PAQ criterion validity was variable depending on the PA intensity groups (ρ = 0.26, 0.07, 0.39; к = 0.14, 0.04, 0.16 for sedentary, light, moderate/vigorous physical activity (MVPA) respectively). Sedentary and light intensity activities from the questionnaire were underestimated when compared to the criterion data while MVPA in APCAPS-PAQ was overestimated. Higher time spent in sedentary activity in APCAPS-PAQ was associated with higher BMI and percent body fat, suggesting construct validity. CONCLUSIONS: The APCAPS-PAQ validity is comparable to other physical activity questionnaires. This tool is able to assess sedentary behavior, moderate/vigorous activity and physical activity energy expenditure on a group level with reasonable validity. This new questionnaire may be used for ranking individuals according to their sedentary time and physical activity in southern India

    Evaluation of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ): a cross-sectional study.

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    BACKGROUND: Socio-cultural differences for country-specific activities are rarely addressed in physical activity questionnaires. We examined the reliability and validity of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ) in urban and rural groups in India. METHODS: A sub-sample of IMS participants (n = 479) was used to examine short term (≤ 1 month [n = 158]) and long term (> 1 month [n = 321]) IMS-PAQ reliability for levels of total, sedentary, light and moderate/vigorous activity (MVPA) intensity using intraclass correlation (ICC) and kappa coefficients (k). Criterion validity (n = 157) was examined by comparing the IMS-PAQ to a uniaxial accelerometer (ACC) worn ≥ 4 days, via Spearman's rank correlations (ρ) and k, using Bland-Altman plots to check for systematic bias. Construct validity (n = 7,000) was established using linear regression, comparing IMS-PAQ against theoretical constructs associated with physical activity (PA): BMI [kg/m2], percent body fat and pulse rate. RESULTS: IMS-PAQ reliability ranged from ICC 0.42-0.88 and k = 0.37-0.61 (≤ 1 month) and ICC 0.26 to 0.62; kappa 0.17 to 0.45 (> 1 month). Criterion validity was ρ = 0.18-0.48; k = 0.08-0.34. Light activity was underestimated and MVPA consistently and substantially overestimated for the IMS-PAQ vs. the accelerometer. Criterion validity was moderate for total activity and MVPA. Reliability and validity were comparable for urban and rural participants but lower in women than men. Increasing time spent in total activity or MVPA, and decreasing time in sedentary activity were associated with decreasing BMI, percent body fat and pulse rate, thereby demonstrating construct validity. CONCLUSION: IMS-PAQ reliability and validity is similar to comparable self-reported instruments. It is an appropriate tool for ranking PA of individuals in India. Some refinements may be required for sedentary populations and women in India.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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