325 research outputs found
Synthesis and generation of evidence to meet stakeholder needs in a pluralistic health system
No full textSystematic reviews evaluating effects of health care interventions : issues of synthesis and bias
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Finding evidence to inform the conduct and reporting of systematic reviews of randomized trials
No full textDEFINING BIOMARKER PERFORMANCE AND CLINICAL VALIDITY
No full textIn the evaluation of biomarkers three questions can be answered: what is the analytical validity of the marker, what is its clinical validity, and does the marker have clinical utility? In most cases, clinical validity will be expressed in terms of the marker's accuracy: the degree to which it can be used to correctly identify diseased patients or, more generally, patients with the target condition. Diagnostic accuracy is evaluated in studies in which the biomarker values are compared to the outcome of the clinical reference standard in the same patients. There are several ways in which the results of diagnostic accuracy studies can be summarized, reported, and interpreted. In this paper we summarize and present the available measures. We classify these as error-based measures, information-based measures, and measures of the strength of the association. Clinical validity is linked to clinical utility. If the target condition is well defined and associated with unequivocal downstream management decisions, clinical validity, when defined in comparative terms, may sometimes act as a surrogate outcome measure for clinical utilit
Magnetic resonance imaging and computed tomography : applications in colorectal cancer surveillance and evaluation of Crohn's disease
No full textImaging research: Improving the quality of systematic reviews and diagnostic test accuracy studies
No full textThis thesis’ objective was to address issues in: A) Imaging diagnostic accuracy research; B) Imaging diagnostic accuracy systematic reviews and C) Imaging meta-research in the form of evaluation of reporting and methods. This first section focuses on primary diagnostic accuracy research in imaging. Chapter 2 describes an evaluation of the use of CT for evaluation of internal hernia in the cohort of patients who have had laparoscopic Roux-en-Y gastric bypass surgery using surgery and long term clinical follow up as a reference standard. Chapter 3 describes an evaluation of the diagnostic accuracy of quantitative CT texture analysis to differentiate fat-poor renal angiomyolipoma from renal cell carcinoma on unenhanced CT. The second section presents examples of systematic review and meta-analysis of imaging research. Chapter 4 is a systematic review of Accuracy of Gadoxetic Acid-enhanced MRI Imaging for Focal Nodular Hyperplasia vs. Hepatocellular Adenoma. Chapter 5 is a systematic review evaluating the complication rate and diagnostic accuracy of image-guided biopsy of the spleen. This third section documents meta-research and guidance on imaging diagnostic accuracy primary research and systematic reviews. Chapter 6 evaluates quality and completeness of reporting of imaging systematic reviews. Chapter 7 evaluates techniques used for meta-analyses in imaging diagnostic accuracy systematic reviews and their effect on summary estimates of diagnostic accuracy. Chapter 8 is a guidance paper on common pitfalls for systematic reviews in imaging research. Chapter 9 evaluates adherence of imaging diagnostic accuracy studies to STARD 2015. Chapter 10 describes persistent deficiencies and new questions raised by our work
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