755 research outputs found
What can available randomised controlled trials evaluating monitoring strategies tell us about the design and analysis of future trials?
Selection and Presentation of Imaging Figures in the Medical Literature
Background: Images are important for conveying information, but there is no empirical evidence on whether imaging figures are properly selected and presented in the published medical literature. We therefore evaluated the selection and presentation of radiological imaging figures in major medical journals. Methodology/Principal Findings: We analyzed articles published in 2005 in 12 major general and specialty medical journals that had radiological imaging figures. For each figure, we recorded information on selection, study population, provision of quantitative measurements, color scales and contrast use. Overall, 417 images from 212 articles were analyzed. Any comment/hint on image selection was made in 44 (11%) images (range 0–50% across the 12 journals) and another 37 (9%) (range 0–60%) showed both a normal and abnormal appearance. In 108 images (26%) (range 0–43%) it was unclear whether the image came from the presented study population. Eighty-three images (20%) (range 0–60%) had any quantitative or ordered categorical value on a measure of interest. Information on the distribution of the measure of interest in the study population was given in 59 cases. For 43 images (range 0–40%), a quantitative measurement was provided for the depicted case and the distribution of values in the study population was also available; in those 43 cases there was no over-representation of extreme than average cases (p = 0.37). Significance: The selection and presentation of images in the medical literature is often insufficiently documented; quantitative data are sparse and difficult to place in context
Chapter 3: Choosing the Important Outcomes for a Systematic Review of a Medical Test
In this chapter of the Evidence-based Practice Centers Methods Guide for Medical Tests, we describe how the decision to use a medical test generates a broad range of outcomes and that each of these outcomes should be considered for inclusion in a systematic review. Awareness of these varied outcomes affects how a decision maker balances the benefits and risks of the test; therefore, a systematic review should present the evidence on these diverse outcomes. The key outcome categories include clinical management outcomes and direct health effects; emotional, social, cognitive, and behavioral responses to testing; legal and ethical outcomes, and costs. We describe the challenges of incorporating these outcomes in a systematic review, suggest a framework for generating potential outcomes for inclusion, and describe the role of stakeholders in choosing the outcomes for study. Finally, we give examples of systematic reviews that either included a range of outcomes or that might have done so. The following are the key messages in this chapter:
Consider both the outcomes that are relevant to the process of testing and those that are relevant to the results of the test.Consider inclusion of outcomes in all five domains: clinical management effects, direct test effects; emotional, social, cognitive and behavioral effects; legal and ethical effects, and costs.Consider to which group the outcomes of testing are most relevant.Given resource limitations, prioritize which outcomes to include. This decision depends on the needs of the stakeholder(s), who should be assisted in prioritizing the outcomes for inclusion
Performance of non-invasive tests and histology for the prediction of clinical outcomes in patients with non-alcoholic fatty liver disease: an individual participant data meta-analysis
Using patient management as a surrogate for patient health outcomes in diagnostic test evaluation
<p>Abstract</p> <p>Background</p> <p>Before a new test is introduced in clinical practice, evidence is needed to demonstrate that its use will lead to improvements in patient health outcomes. Studies reporting test accuracy may not be sufficient, and clinical trials of tests that measure patient health outcomes are rarely feasible. Therefore, the consequences of testing on patient management are often investigated as an intermediate step in the pathway. There is a lack of guidance on the interpretation of this evidence, and patient management studies often neglect a discussion of the limitations of measuring patient management as a surrogate for health outcomes.</p> <p>Methods</p> <p>We discuss the rationale for measuring patient management, describe the common study designs and provide guidance about how this evidence should be reported.</p> <p>Results</p> <p>Interpretation of patient management studies relies on the condition that patient management is a valid surrogate for downstream patient benefits. This condition presupposes two critical assumptions: the test improves diagnostic accuracy; and the measured changes in patient management improve patient health outcomes. The validity of this evidence depends on the certainty around these critical assumptions and the ability of the study design to minimise bias. Three common designs are test RCTs that measure patient management as a primary endpoint, diagnostic before-after studies that compare planned patient management before and after testing, and accuracy studies that are extended to report on the actual treatment or further tests received following a positive and negative test result.</p> <p>Conclusions</p> <p>Patient management can be measured as a surrogate outcome for test evaluation if its limitations are recognised. The potential consequences of a positive and negative test result on patient management should be pre-specified and the potential patient benefits of these management changes clearly stated. Randomised comparisons will provide higher quality evidence about differences in patient management using the new test than observational studies. Regardless of the study design used, the critical assumption that patient management is a valid surrogate for downstream patient benefits or harms must be discussed in these studies.</p
Variation in the observed effect of Xpert MTB/RIF testing for tuberculosis on mortality: A systematic review and analysis of trial design considerations [version 2; peer review: 3 approved]
Background: Most studies evaluating the effect of Xpert MTB/RIF testing for tuberculosis (TB) concluded that it did not reduce overall mortality compared to usual care. We conducted a systematic review to assess whether key study design and execution features contributed to earlier identification of patients with TB and decreased pre-treatment loss to follow-up, thereby reducing the potential impact of Xpert MTB/RIF testing. /
Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Scopus for literature published from 1st January 2009 to February 2019. We included all primary intervention studies that had evaluated the effect of Xpert MTB/RIF on mortality compared to usual care in participants with presumptive pulmonary TB. We critically reviewed features of included studies across: Study setting and context, Study population, Participant recruitment and enrolment, Study procedures, and Study follow-up. /
Results: We included seven randomised and one non-randomised study. All included studies demonstrated relative reductions in overall mortality in the Xpert MTB/RIF arm ranging from 6% to 40%. However, mortality reduction was reported to be statistically significant in two studies. Study features that could explain the lack of observed effect on mortality included: the higher quality of care at study sites; inclusion of patients with a higher pre-test probability of TB leading to higher than expected empirical rates; performance of additional diagnostic testing not done in usual care leading to increased TB diagnosis or empiric treatment initiation; the recruitment of participants likely to return for follow-up; and involvement of study staff in ensuring adherence with care and follow-up. /
Conclusion: Most studies of Xpert MTB/RIF were designed and conducted in a manner that resulted in more patients being diagnosed and treated for TB, minimising the potential difference in mortality Xpert MTB/RIF testing could have achieved compared to usual care
STARD for Abstracts: Essential items for reporting diagnostic accuracy studies in journal or conference abstracts
Many abstracts of diagnostic accuracy studies are currently insufficiently informative. We extended the STARD (Standards for Reporting Diagnostic Accuracy) statement by developing a list of essential items that authors should consider when reporting diagnostic accuracy studies in journal or conference abstracts. After a literature review of published guidance for reporting biomedical studies, we identified 39 items potentially relevant to report in an abstract. We then selected essential items through a two round web based survey among the 85 members of the STARD Group, followed by discussions within an executive committee. Seventy three STARD Group members responded (86%), with 100% completion rate. STARD for Abstracts is a list of 11 quintessential items, to be reported in every abstract of a diagnostic accuracy study. We provide examples of complete reporting, and developed template text for writing informative abstract
Guidance for Developers of Health Research Reporting Guidelines
David Moher and colleagues from the EQUATOR network offer guidance and recommended steps for developing health research reporting guidelines
Prediction of an excessive response in in vitro fertilization from patient characteristics and ovarian reserve tests and comparison in subgroups: an individual patient data meta-analysis.
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