Browsing by Subject "Review Literature as Topic"

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    Assessing applicability when comparing medical interventions: AHRQ and the Effective Health Care Program.
    (Journal of clinical epidemiology, 2011-11) Atkins, David; Chang, Stephanie M; Gartlehner, Gerald; Buckley, David I; Whitlock, Evelyn P; Berliner, Elise; Matchar, David

    Objective

    To describe a systematic approach for identifying, reporting, and synthesizing information to allow consistent and transparent consideration of the applicability of the evidence in a systematic review according to the Population, Intervention, Comparator, Outcome, Setting domains.

    Study design and setting

    Comparative effectiveness reviews need to consider whether available evidence is applicable to specific clinical or policy questions to be useful to decision makers. Authors reviewed the literature and developed guidance for the Effective Health Care program.

    Results

    Because applicability depends on the specific questions and needs of the users, it is difficult to devise a valid uniform scale for rating the overall applicability of individual studies or body of evidence. We recommend consulting stakeholders to identify the factors most relevant to applicability for their decisions. Applicability should be considered separately for benefits and harms. Observational studies can help determine whether trial populations and interventions are representative of "real world" practice. Reviewers should describe differences between available evidence and the ideally applicable evidence for the question being asked and offer a qualitative judgment about the importance and potential effect of those differences.

    Conclusion

    Careful consideration of applicability may improve the usefulness of systematic reviews in informing practice and policy.
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    Chapter 11: challenges in and principles for conducting systematic reviews of genetic tests used as predictive indicators.
    (Journal of general internal medicine, 2012-06) Jonas, Daniel E; Wilt, Timothy J; Taylor, Brent C; Wilkins, Tania M; Matchar, David B
    In this paper, we discuss common challenges in and principles for conducting systematic reviews of genetic tests. The types of genetic tests discussed are those used to 1). determine risk or susceptibility in asymptomatic individuals; 2). reveal prognostic information to guide clinical management in those with a condition; or 3). predict response to treatments or environmental factors. This paper is not intended to provide comprehensive guidance on evaluating all genetic tests. Rather, it focuses on issues that have been of particular concern to analysts and stakeholders and on areas that are of particular relevance for the evaluation of studies of genetic tests. The key points include: The general principles that apply in evaluating genetic tests are similar to those for other prognostic or predictive tests, but there are differences in how the principles need to be applied or the degree to which certain issues are relevant. A clear definition of the clinical scenario and an analytic framework is important when evaluating any test, including genetic tests. Organizing frameworks and analytic frameworks are useful constructs for approaching the evaluation of genetic tests. In constructing an analytic framework for evaluating a genetic test, analysts should consider preanalytic, analytic, and postanalytic factors; such factors are useful when assessing analytic validity. Predictive genetic tests are generally characterized by a delayed time between testing and clinically important events. Finding published information on the analytic validity of some genetic tests may be difficult. Web sites (FDA or diagnostic companies) and gray literature may be important sources. In situations where clinical factors associated with risk are well characterized, comparative effectiveness reviews should assess the added value of using genetic testing along with known factors compared with using the known factors alone. For genome-wide association studies, reviewers should determine whether the association has been validated in multiple studies to minimize both potential confounding and publication bias. In addition, reviewers should note whether appropriate adjustments for multiple comparisons were used.
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    Chapter 1: Introduction to the Methods Guide for Medical Test Reviews.
    (Journal of general internal medicine, 2012-06) Matchar, David B
    Evaluation of medical tests presents challenges distinct from those involved in the evaluation of therapies; in particular, the very great importance of context and the dearth of comprehensive RCTs aimed at comparing the clinical outcomes of different tests and test strategies. Available guidance provides some suggestions: 1) Use of the PICOTS typology for clarifying the context relevant to the review, and 2) use of an organizing framework for classifying the types of medical test evaluation studies and their relationship to potential key questions. However, there is a diversity of recommendations for reviewers of medical tests and a proliferation of concepts, terms, and methods. As a contribution to the field, this Methods Guide for Medical Test Reviews seeks to provide practical guidance for achieving the goals of clarity, consistency, tractability, and usefulness.
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    Chapter 5: assessing risk of bias as a domain of quality in medical test studies.
    (Journal of general internal medicine, 2012-06) Santaguida, P Lina; Riley, Crystal M; Matchar, David B
    Assessing methodological quality is a necessary activity for any systematic review, including those evaluating the evidence for studies of medical test performance. Judging the overall quality of an individual study involves examining the size of the study, the direction and degree of findings, the relevance of the study, and the risk of bias in the form of systematic error, internal validity, and other study limitations. In this chapter of the Methods Guide for Medical Test Reviews, we focus on the evaluation of risk of bias in the form of systematic error in an individual study as a distinctly important component of quality in studies of medical test performance, specifically in the context of estimating test performance (sensitivity and specificity). We make the following recommendations to systematic reviewers: 1) When assessing study limitations that are relevant to the test under evaluation, reviewers should select validated criteria that examine the risk of systematic error, 2) categorizing the risk of bias for individual studies as "low," "medium," or "high" is a useful way to proceed, and 3) methods for determining an overall categorization for the study limitations should be established a priori and documented clearly.
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    Chapter 6: assessing applicability of medical test studies in systematic reviews.
    (Journal of general internal medicine, 2012-06) Hartmann, KE; Matchar, DB; Chang, S
    Use of medical tests should be guided by research evidence about the accuracy and utility of those tests in clinical care settings. Systematic reviews of the literature about medical tests must address applicability to real-world decision-making. Challenges for reviews include: (1) lack of clarity in key questions about the intended applicability of the review, (2) numerous studies in many populations and settings, (3) publications that provide too little information to assess applicability, (4) secular trends in prevalence and the spectrum of the condition for which the test is done, and (5) changes in the technology of the test itself. We describe principles for crafting reviews that meet these challenges and capture the key elements from the literature necessary to understand applicability.
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    Chapter 7: grading a body of evidence on diagnostic tests.
    (Journal of general internal medicine, 2012-06) Singh, Sonal; Chang, Stephanie M; Matchar, David B; Bass, Eric B

    Introduction

    Grading the strength of a body of diagnostic test evidence involves challenges over and above those related to grading the evidence from health care intervention studies. This chapter identifies challenges and outlines principles for grading the body of evidence related to diagnostic test performance.

    Challenges

    Diagnostic test evidence is challenging to grade because standard tools for grading evidence were designed for questions about treatment rather than diagnostic testing; and the clinical usefulness of a diagnostic test depends on multiple links in a chain of evidence connecting the performance of a test to changes in clinical outcomes.

    Principles

    Reviewers grading the strength of a body of evidence on diagnostic tests should consider the principle domains of risk of bias, directness, consistency, and precision, as well as publication bias, dose response association, plausible unmeasured confounders that would decrease an effect, and strength of association, similar to what is done to grade evidence on treatment interventions. Given that most evidence regarding the clinical value of diagnostic tests is indirect, an analytic framework must be developed to clarify the key questions, and strength of evidence for each link in that framework should be graded separately. However if reviewers choose to combine domains into a single grade of evidence, they should explain their rationale for a particular summary grade and the relevant domains that were weighed in assigning the summary grade.
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    Gene-environment interactions: neurodegeneration in non-mammals and mammals.
    (Neurotoxicology, 2010-09) Aschner, Michael; Levin, Edward D; Suñol, Cristina; Olopade, James O; Helmcke, Kirsten J; Avila, Daiana S; Sledge, Damiyon; Ali, Rahim H; Upchurch, Lucia; Donerly, Susan; Linney, Elwood; Forsby, Anna; Ponnuru, Padmavathi; Connor, James R
    The understanding of how environmental exposures interact with genetics in central nervous system dysfunction has gained great momentum in the last decade. Seminal findings have been uncovered in both mammalian and non-mammalian model in large result of the extraordinary conservation of both genetic elements and differentiation processes between mammals and non-mammalians. Emerging model organisms, such as the nematode and zebrafish have made it possible to assess the effects of small molecules rapidly, inexpensively, and on a miniaturized scale. By combining the scale and throughput of in vitro screens with the physiological complexity and traditional animal studies, these models are providing relevant information on molecular events in the etiology of neurodegenerative disorders. The utility of these models is largely driven by the functional conservation seen between them and higher organisms, including humans so that knowledge obtained using non-mammalian model systems can often provide a better understanding of equivalent processes, pathways, and mechanisms in man. Understanding the molecular events that trigger neurodegeneration has also greatly relied upon the use of tissue culture models. The purpose of this summary is to provide-state-of-the-art review of recent developments of non-mammalian experimental models and their utility in addressing issues pertinent to neurotoxicity (Caenorhabditis elegans and Danio rerio). The synopses by Aschner and Levin summarize how genetic mutants of these species can be used to complement the understanding of molecular and cellular mechanisms associated with neurobehavioral toxicity and neurodegeneration. Next, studies by Suñol and Olopade detail the predictive value of cultures in assessing neurotoxicity. Suñol and colleagues summarize present novel information strategies based on in vitro toxicity assays that are predictive of cellular effects that can be extrapolated to effects on individuals. Olopade and colleagues describe cellular changes caused by sodium metavanadate (SMV) and demonstrate how rat primary astrocyte cultures can be used as predicitive tools to assess the neuroprotective effects of antidotes on vanadium-induced astrogliosis and demyelination.
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    Methods guide for authors of systematic reviews of medical tests: a collaboration between the Agency for Healthcare Research and Quality (AHRQ) and the Journal of General Internal Medicine.
    (Journal of general internal medicine, 2012-06) Smetana, Gerald W; Umscheid, Craig A; Chang, Stephanie; Matchar, David B
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    Nonpharmacologic, nonherbal management of menopause-associated vasomotor symptoms: an umbrella systematic review (protocol).
    (Syst Rev, 2016-04-07) Goldstein, Karen M; McDuffie, Jennifer R; Shepherd-Banigan, Megan; Befus, Deanna; Coeytaux, Remy R; Van Noord, Megan G; Goode, Adam P; Masilamani, Varsha; Adam, Soheir; Nagi, Avishek; Williams, John W
    BACKGROUND: Vasomotor symptoms such as hot flashes and night sweats are a common concern of perimenopausal and postmenopausal women and are associated with a decreased quality of life. These symptoms can be effectively managed with hormone therapy, but safety concerns limit its use. Thus, understanding the effectiveness of nonpharmacologic therapies such as acupuncture or yoga is critical to managing these common symptoms in older women. Our review seeks to address the following question: In women with menopause-associated vasomotor symptoms, what are the effects on health-related quality of life, vasomotor symptoms, and adverse events of the following nonpharmacologic, nonherbal interventions as compared with any inactive control or active comparator: (a) acupuncture, (b) yoga, tai chi, and qigong, (c) structured exercise, and (d) meditation, mindfulness-based practices, and relaxation? METHODS: We describe a protocol for an umbrella review approach, supplemented by evaluating randomized controlled trials (RCTs) published after the most recent good-quality systematic review for each of the eligible interventions. Specific interventions were chosen based on current literature and with input from a technical expert panel and organizational stakeholders. We will conduct a thorough literature search and perform a quality assessment of potentially included systematic reviews and RCTs. DISCUSSION: Our umbrella review, supplemented by an additional search for eligible RCTs, aims to synthesize existing evidence on the use of nonpharmacologic, nonherbal interventions to manage bothersome vasomotor symptoms in perimenopausal and postmenopausal women. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016029335.