Gunn Vist - Academia.edu (original) (raw)
Papers by Gunn Vist
Allergy, 2009
Clinical guidelines are only as good as the evidence and judgments they are based on. The GRADE a... more Clinical guidelines are only as good as the evidence and judgments they are based on. The GRADE approach aims to make it easier for users to assess the judgments behind recommendations This is an abridged version; the full version is on bmj.com
BMJ open, 2014
To cite: Berg RC, Underland V, Odgaard-Jensen J, et al. Effects of female genital cutting on phys... more To cite: Berg RC, Underland V, Odgaard-Jensen J, et al. Effects of female genital cutting on physical health outcomes: a systematic review and metaanalysis.
CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, Jan 30, 2003
The GRADE Working Group is developing and evaluating a common, sensible approach to grading quali... more The GRADE Working Group is developing and evaluating a common, sensible approach to grading quality of evidence and strength of recommendations in health care. In this article, we discuss the advantages and disadvantages of using letters, numbers, symbols or words to represent grades of evidence and recommendations. Using multiple strategies, we searched for comparative studies of alternative ways of representing ordered categories in any context. In addition, we contacted experts and reviewed theoretical work and qualitative research on how best to communicate grades of any kind quickly and clearly. We were unable to identify health care research that addressed, either directly or indirectly, the best way to present grades of evidence and recommendations. We found examples of symbols used by government, commercial and consumer organizations to communicate quality of evidence or strength of recommendations, but no comparative studies. Although a number of grading systems are used in health care and other fields, there is little or no evidence of how well various presentations are understood. Before promoting the use of specific symbols, numbers, letters or words, the extent to which the intended message is comprehended should be evaluated.
In the GRADE approach, randomized trials start as high-quality evidence and observational studies... more In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if most of the relevant evidence comes from studies that suffer from a high risk of bias. Well-established limitations of randomized trials include failure to conceal allocation, failure to blind, loss to follow-up, and failure to appropriately consider the intentionto-treat principle. More recently recognized limitations include stopping early for apparent benefit and selective reporting of outcomes according to the results. Key limitations of observational studies include use of inappropriate controls and failure to adequately adjust for prognostic imbalance. Risk of bias may vary across outcomes (e.g., loss to follow-up may be far less for all-cause mortality than for quality of life), a consideration that many systematic reviews ignore. In deciding whether to rate down for risk of biasdwhether for randomized trials or observational studiesdauthors should not take an approach that averages across studies. Rather, for any individual outcome, when there are some studies with a high risk, and some with a low risk of bias, they should consider including only the studies with a lower risk of bias. Ó
Scandinavian Cardiovascular Journal, 2008
To perform a systematic review of randomized controlled trials (RCTs) on catheter ablation for at... more To perform a systematic review of randomized controlled trials (RCTs) on catheter ablation for atrial fibrillation (AF). Radiofrequency catheter (RF)-ablation around pulmonary vein ostia and in left atrium may reduce or prevent recurrence of AF, as documented in observational studies and registry reports; however, few RCTs are available. Using relevant search phrases, Cochrane Library, MEDLINE and EMBASE were searched for RCTs, last time in May 2007. Titles and abstracts were screened. When entry criteria were fulfilled, full-text papers were read and graded according to quality and relevance. One thousand and ninety four abstracts were evaluated, and five RCTs included (578 randomized patients). The studies had moderate quality and relevance, but the results were consistent: ablation is better than drug treatment in preventing AF recurrence; the relative risk (95% CI)) one year after ablation ranged from 0.20 (0.08-0.51) to 0.62 (0.39-0.99). Results from observational and registry studies are confirmed: RF-ablation reduces recurrence rate of AF, and can be done with few serious complications. Limitations are few patients>70 years, and only one year follow-up.
Journal of Clinical Epidemiology, 2013
This article describes the Grading of Recommendations Assessment, Development, and Evaluation (GR... more This article describes the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to classifying the direction and strength of recommendations. The strength of a recommendation, separated into strong and weak, is defined as the extent to which one can be confident that the desirable effects of an intervention outweigh its undesirable effects. Alternative terms for a weak recommendation include conditional, discretionary, or qualified. The strength of a recommendation has specific implications for patients, the public, clinicians, and policy makers. Occasionally, guideline developers may choose to make ''only-in-research'' recommendations. Although panels may choose not to make recommendations, this choice leaves those looking for answers from guidelines without the guidance they are seeking. GRADE therefore encourages panels to, wherever possible, offer recommendations. Ó
Journal of Clinical …, 2011
In the GRADE approach, randomized trials start as high-quality evidence and observational studies... more In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if a body of evidence is associated with a high risk of publication bias. Even when individual studies included in bestevidence summaries have a low risk of bias, publication bias can result in substantial overestimates of effect. Authors should suspect publication bias when available evidence comes from a number of small studies, most of which have been commercially funded. A number of approaches based on examination of the pattern of data are available to help assess publication bias. The most popular of these is the funnel plot; all, however, have substantial limitations. Publication bias is likely frequent, and caution in the face of early results, particularly with small sample size and number of events, is warranted. Ó
Zusammenfassung Der häufigste Grund für das Heraufstufen der Qualität von Evidenz ist das Vorlieg... more Zusammenfassung Der häufigste Grund für das Heraufstufen der Qualität von Evidenz ist das Vorliegen eines großen Effekts. Der GRADE-Ansatz empfiehlt das Heraufstufen der Qualität der Evidenz um eine Stufe, wenn methodisch präzise durchgeführte Beobachtungsstudien eine mehr als zweifache Reduktion oder einen mehr als zweifachen Anstieg des Risikos zeigen, und das Heraufstufen um zwei Stufen, wenn das Relative Risiko kleiner als 0,2 bzw. größer als 5 ist. Autoren von systematischen Übersichtsarbeiten und Entwickler von Leitlinien können ebenfalls ein Heraufstufen der Qualität in Erwägung ziehen, wenn eine Dosis-Wirkungs-Beziehung vorliegt oder wenn alle plausiblen Confounder oder Verzerrungen den gezeigten Behandlungseffekt eher reduzieren bzw. einen scheinbaren Effekt erzeugen würden, während die vorhandenen Ergebnisse keinen Effekt zeigen. Andere Überlegungen beziehen sich auf die Schnelligkeit, mit der sich ein Effekt einstellt, den zugrunde liegenden Verlauf der Erkrankung und das Vorliegen von indirekter Evidenz.
This article deals with inconsistency of relative (rather than absolute) treatment effects in bin... more This article deals with inconsistency of relative (rather than absolute) treatment effects in binary/dichotomous outcomes. A body of evidence is not rated up in quality if studies yield consistent results, but may be rated down in quality if inconsistent. Criteria for evaluating consistency include similarity of point estimates, extent of overlap of confidence intervals, and statistical criteria including tests of heterogeneity and I 2 . To explore heterogeneity, systematic review authors should generate and test a small number of a priori hypotheses related to patients, interventions, outcomes, and methodology. When inconsistency is large and unexplained, rating down quality for inconsistency is appropriate, particularly if some studies suggest substantial benefit, and others no effect or harm (rather than only large vs. small effects).
This article is the first of a series providing guidance for use of the Grading of Recommendation... more This article is the first of a series providing guidance for use of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system of rating quality of evidence and grading strength of recommendations in systematic reviews, health technology assessments (HTAs), and clinical practice guidelines addressing alternative management options. The GRADE process begins with asking an explicit question, including specification of all important outcomes. After the evidence is collected and summarized, GRADE provides explicit criteria for rating the quality of evidence that include study design, risk of bias, imprecision, inconsistency, indirectness, and magnitude of effect.
Journal of clinical …, 2011
In the GRADE approach, randomized trials start as high-quality evidence and observational studies... more In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if most of the relevant evidence comes from studies that suffer from a high risk of bias. Well-established limitations of randomized trials include failure to conceal allocation, failure to blind, loss to follow-up, and failure to appropriately consider the intentionto-treat principle. More recently recognized limitations include stopping early for apparent benefit and selective reporting of outcomes according to the results. Key limitations of observational studies include use of inappropriate controls and failure to adequately adjust for prognostic imbalance. Risk of bias may vary across outcomes (e.g., loss to follow-up may be far less for all-cause mortality than for quality of life), a consideration that many systematic reviews ignore. In deciding whether to rate down for risk of biasdwhether for randomized trials or observational studiesdauthors should not take an approach that averages across studies. Rather, for any individual outcome, when there are some studies with a high risk, and some with a low risk of bias, they should consider including only the studies with a lower risk of bias. Ó
… (Clinical research ed. …, 2004
Clinical guidelines are only as good as the evidence and judgments they are based on. The GRADE a... more Clinical guidelines are only as good as the evidence and judgments they are based on. The GRADE approach aims to make it easier for users to assess the judgments behind recommendations This is an abridged version; the full version is on bmj.com
Journal of clinical epidemiology, Dec 31, 2011
Direct evidence comes from research that directly compares the interventions in which we are inte... more Direct evidence comes from research that directly compares the interventions in which we are interested when applied to the populations in which we are interested and measures outcomes important to patients. Evidence can be indirect in one of four ways. First, patients may differ from those of interest (the term applicability is often used for this form of indirectness). Secondly, the intervention tested may differ from the intervention of interest. Decisions regarding indirectness of patients and interventions depend on an understanding of whether biological or social factors are sufficiently different that one might expect substantial differences in the magnitude of effect.
Journal of Health …, 2002
The empirical basis for theories and common wisdom regarding how to improve appropriate use of re... more The empirical basis for theories and common wisdom regarding how to improve appropriate use of research evidence in policy decisions is unclear. One source of empirical evidence is interview studies with policymakers. The aim of this systematic review was to summarise the evidence from interview studies of facilitators of, and barriers to, the use of research evidence by health policy-makers.
BMC Geriatrics, 2011
Background: Studies have shown that residents in nursing homes often are exposed to inappropriate... more Background: Studies have shown that residents in nursing homes often are exposed to inappropriate medication. Particular concern has been raised about the consumption of psychoactive drugs, which are commonly prescribed for nursing home residents suffering from dementia. This review is an update of a Norwegian systematic review commissioned by the Norwegian Directorate of Health. The purpose of the review was to identify and summarise the effect of interventions aimed at reducing potentially inappropriate use or prescribing of drugs in nursing homes. Methods: We searched for systematic reviews and randomised controlled trials in the Cochrane Library, MEDLINE, EMBASE, ISI Web of Knowledge, DARE and HTA, with the last update in April 2010. Two of the authors independently screened titles and abstracts for inclusion or exclusion. Data on interventions, participants, comparison intervention, and outcomes were extracted from the included studies. Risk of bias and quality of evidence were assessed using the Cochrane Risk of Bias Table and GRADE, respectively. Outcomes assessed were use of or prescribing of drugs (primary) and the health-related outcomes falls, physical limitation, hospitalisation and mortality (secondary).
Tidsskrift for Den norske legeforening, 2012
Allergy, 2009
Clinical guidelines are only as good as the evidence and judgments they are based on. The GRADE a... more Clinical guidelines are only as good as the evidence and judgments they are based on. The GRADE approach aims to make it easier for users to assess the judgments behind recommendations This is an abridged version; the full version is on bmj.com
BMJ open, 2014
To cite: Berg RC, Underland V, Odgaard-Jensen J, et al. Effects of female genital cutting on phys... more To cite: Berg RC, Underland V, Odgaard-Jensen J, et al. Effects of female genital cutting on physical health outcomes: a systematic review and metaanalysis.
CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, Jan 30, 2003
The GRADE Working Group is developing and evaluating a common, sensible approach to grading quali... more The GRADE Working Group is developing and evaluating a common, sensible approach to grading quality of evidence and strength of recommendations in health care. In this article, we discuss the advantages and disadvantages of using letters, numbers, symbols or words to represent grades of evidence and recommendations. Using multiple strategies, we searched for comparative studies of alternative ways of representing ordered categories in any context. In addition, we contacted experts and reviewed theoretical work and qualitative research on how best to communicate grades of any kind quickly and clearly. We were unable to identify health care research that addressed, either directly or indirectly, the best way to present grades of evidence and recommendations. We found examples of symbols used by government, commercial and consumer organizations to communicate quality of evidence or strength of recommendations, but no comparative studies. Although a number of grading systems are used in health care and other fields, there is little or no evidence of how well various presentations are understood. Before promoting the use of specific symbols, numbers, letters or words, the extent to which the intended message is comprehended should be evaluated.
In the GRADE approach, randomized trials start as high-quality evidence and observational studies... more In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if most of the relevant evidence comes from studies that suffer from a high risk of bias. Well-established limitations of randomized trials include failure to conceal allocation, failure to blind, loss to follow-up, and failure to appropriately consider the intentionto-treat principle. More recently recognized limitations include stopping early for apparent benefit and selective reporting of outcomes according to the results. Key limitations of observational studies include use of inappropriate controls and failure to adequately adjust for prognostic imbalance. Risk of bias may vary across outcomes (e.g., loss to follow-up may be far less for all-cause mortality than for quality of life), a consideration that many systematic reviews ignore. In deciding whether to rate down for risk of biasdwhether for randomized trials or observational studiesdauthors should not take an approach that averages across studies. Rather, for any individual outcome, when there are some studies with a high risk, and some with a low risk of bias, they should consider including only the studies with a lower risk of bias. Ó
Scandinavian Cardiovascular Journal, 2008
To perform a systematic review of randomized controlled trials (RCTs) on catheter ablation for at... more To perform a systematic review of randomized controlled trials (RCTs) on catheter ablation for atrial fibrillation (AF). Radiofrequency catheter (RF)-ablation around pulmonary vein ostia and in left atrium may reduce or prevent recurrence of AF, as documented in observational studies and registry reports; however, few RCTs are available. Using relevant search phrases, Cochrane Library, MEDLINE and EMBASE were searched for RCTs, last time in May 2007. Titles and abstracts were screened. When entry criteria were fulfilled, full-text papers were read and graded according to quality and relevance. One thousand and ninety four abstracts were evaluated, and five RCTs included (578 randomized patients). The studies had moderate quality and relevance, but the results were consistent: ablation is better than drug treatment in preventing AF recurrence; the relative risk (95% CI)) one year after ablation ranged from 0.20 (0.08-0.51) to 0.62 (0.39-0.99). Results from observational and registry studies are confirmed: RF-ablation reduces recurrence rate of AF, and can be done with few serious complications. Limitations are few patients>70 years, and only one year follow-up.
Journal of Clinical Epidemiology, 2013
This article describes the Grading of Recommendations Assessment, Development, and Evaluation (GR... more This article describes the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to classifying the direction and strength of recommendations. The strength of a recommendation, separated into strong and weak, is defined as the extent to which one can be confident that the desirable effects of an intervention outweigh its undesirable effects. Alternative terms for a weak recommendation include conditional, discretionary, or qualified. The strength of a recommendation has specific implications for patients, the public, clinicians, and policy makers. Occasionally, guideline developers may choose to make ''only-in-research'' recommendations. Although panels may choose not to make recommendations, this choice leaves those looking for answers from guidelines without the guidance they are seeking. GRADE therefore encourages panels to, wherever possible, offer recommendations. Ó
Journal of Clinical …, 2011
In the GRADE approach, randomized trials start as high-quality evidence and observational studies... more In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if a body of evidence is associated with a high risk of publication bias. Even when individual studies included in bestevidence summaries have a low risk of bias, publication bias can result in substantial overestimates of effect. Authors should suspect publication bias when available evidence comes from a number of small studies, most of which have been commercially funded. A number of approaches based on examination of the pattern of data are available to help assess publication bias. The most popular of these is the funnel plot; all, however, have substantial limitations. Publication bias is likely frequent, and caution in the face of early results, particularly with small sample size and number of events, is warranted. Ó
Zusammenfassung Der häufigste Grund für das Heraufstufen der Qualität von Evidenz ist das Vorlieg... more Zusammenfassung Der häufigste Grund für das Heraufstufen der Qualität von Evidenz ist das Vorliegen eines großen Effekts. Der GRADE-Ansatz empfiehlt das Heraufstufen der Qualität der Evidenz um eine Stufe, wenn methodisch präzise durchgeführte Beobachtungsstudien eine mehr als zweifache Reduktion oder einen mehr als zweifachen Anstieg des Risikos zeigen, und das Heraufstufen um zwei Stufen, wenn das Relative Risiko kleiner als 0,2 bzw. größer als 5 ist. Autoren von systematischen Übersichtsarbeiten und Entwickler von Leitlinien können ebenfalls ein Heraufstufen der Qualität in Erwägung ziehen, wenn eine Dosis-Wirkungs-Beziehung vorliegt oder wenn alle plausiblen Confounder oder Verzerrungen den gezeigten Behandlungseffekt eher reduzieren bzw. einen scheinbaren Effekt erzeugen würden, während die vorhandenen Ergebnisse keinen Effekt zeigen. Andere Überlegungen beziehen sich auf die Schnelligkeit, mit der sich ein Effekt einstellt, den zugrunde liegenden Verlauf der Erkrankung und das Vorliegen von indirekter Evidenz.
This article deals with inconsistency of relative (rather than absolute) treatment effects in bin... more This article deals with inconsistency of relative (rather than absolute) treatment effects in binary/dichotomous outcomes. A body of evidence is not rated up in quality if studies yield consistent results, but may be rated down in quality if inconsistent. Criteria for evaluating consistency include similarity of point estimates, extent of overlap of confidence intervals, and statistical criteria including tests of heterogeneity and I 2 . To explore heterogeneity, systematic review authors should generate and test a small number of a priori hypotheses related to patients, interventions, outcomes, and methodology. When inconsistency is large and unexplained, rating down quality for inconsistency is appropriate, particularly if some studies suggest substantial benefit, and others no effect or harm (rather than only large vs. small effects).
This article is the first of a series providing guidance for use of the Grading of Recommendation... more This article is the first of a series providing guidance for use of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system of rating quality of evidence and grading strength of recommendations in systematic reviews, health technology assessments (HTAs), and clinical practice guidelines addressing alternative management options. The GRADE process begins with asking an explicit question, including specification of all important outcomes. After the evidence is collected and summarized, GRADE provides explicit criteria for rating the quality of evidence that include study design, risk of bias, imprecision, inconsistency, indirectness, and magnitude of effect.
Journal of clinical …, 2011
In the GRADE approach, randomized trials start as high-quality evidence and observational studies... more In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if most of the relevant evidence comes from studies that suffer from a high risk of bias. Well-established limitations of randomized trials include failure to conceal allocation, failure to blind, loss to follow-up, and failure to appropriately consider the intentionto-treat principle. More recently recognized limitations include stopping early for apparent benefit and selective reporting of outcomes according to the results. Key limitations of observational studies include use of inappropriate controls and failure to adequately adjust for prognostic imbalance. Risk of bias may vary across outcomes (e.g., loss to follow-up may be far less for all-cause mortality than for quality of life), a consideration that many systematic reviews ignore. In deciding whether to rate down for risk of biasdwhether for randomized trials or observational studiesdauthors should not take an approach that averages across studies. Rather, for any individual outcome, when there are some studies with a high risk, and some with a low risk of bias, they should consider including only the studies with a lower risk of bias. Ó
… (Clinical research ed. …, 2004
Clinical guidelines are only as good as the evidence and judgments they are based on. The GRADE a... more Clinical guidelines are only as good as the evidence and judgments they are based on. The GRADE approach aims to make it easier for users to assess the judgments behind recommendations This is an abridged version; the full version is on bmj.com
Journal of clinical epidemiology, Dec 31, 2011
Direct evidence comes from research that directly compares the interventions in which we are inte... more Direct evidence comes from research that directly compares the interventions in which we are interested when applied to the populations in which we are interested and measures outcomes important to patients. Evidence can be indirect in one of four ways. First, patients may differ from those of interest (the term applicability is often used for this form of indirectness). Secondly, the intervention tested may differ from the intervention of interest. Decisions regarding indirectness of patients and interventions depend on an understanding of whether biological or social factors are sufficiently different that one might expect substantial differences in the magnitude of effect.
Journal of Health …, 2002
The empirical basis for theories and common wisdom regarding how to improve appropriate use of re... more The empirical basis for theories and common wisdom regarding how to improve appropriate use of research evidence in policy decisions is unclear. One source of empirical evidence is interview studies with policymakers. The aim of this systematic review was to summarise the evidence from interview studies of facilitators of, and barriers to, the use of research evidence by health policy-makers.
BMC Geriatrics, 2011
Background: Studies have shown that residents in nursing homes often are exposed to inappropriate... more Background: Studies have shown that residents in nursing homes often are exposed to inappropriate medication. Particular concern has been raised about the consumption of psychoactive drugs, which are commonly prescribed for nursing home residents suffering from dementia. This review is an update of a Norwegian systematic review commissioned by the Norwegian Directorate of Health. The purpose of the review was to identify and summarise the effect of interventions aimed at reducing potentially inappropriate use or prescribing of drugs in nursing homes. Methods: We searched for systematic reviews and randomised controlled trials in the Cochrane Library, MEDLINE, EMBASE, ISI Web of Knowledge, DARE and HTA, with the last update in April 2010. Two of the authors independently screened titles and abstracts for inclusion or exclusion. Data on interventions, participants, comparison intervention, and outcomes were extracted from the included studies. Risk of bias and quality of evidence were assessed using the Cochrane Risk of Bias Table and GRADE, respectively. Outcomes assessed were use of or prescribing of drugs (primary) and the health-related outcomes falls, physical limitation, hospitalisation and mortality (secondary).
Tidsskrift for Den norske legeforening, 2012