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Find video protocols related to scientific articles indexed in Pubmed.
Comparison of weight loss among named diet programs in overweight and obese adults: a meta-analysis.
JAMA
PUBLISHED: 09-04-2014
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Many claims have been made regarding the superiority of one diet or another for inducing weight loss. Which diet is best remains unclear.
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Recent advances in patient and proxy-reported quality of life research.
Health Qual Life Outcomes
PUBLISHED: 08-29-2014
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A number of articles addressing various aspects of health-related quality of life (HRQoL) were published in the Health and Quality of Life Outcomes (HQLO) journal in 2012 and 2013. This review provides a summary of studies describing recent methodological advances and innovations in HRQoL felt to be of relevance to clinicians and researchers.
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Addressing continuous data measured with different instruments for participants excluded from trial analysis: a guide for systematic reviewers.
J Clin Epidemiol
PUBLISHED: 03-05-2014
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We previously developed an approach to address the impact of missing participant data in meta-analyses of continuous variables in trials that used the same measurement instrument. We extend this approach to meta-analyses including trials that use different instruments to measure the same construct.
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A methodological survey of the analysis, reporting and interpretation of Absolute Risk ReductiOn in systematic revieWs (ARROW): a study protocol.
Syst Rev
PUBLISHED: 09-10-2013
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Clinicians, providers and guideline panels use absolute effects to weigh the advantages and downsides of treatment alternatives. Relative measures have the potential to mislead readers. However, little is known about the reporting of absolute measures in systematic reviews. The objectives of our study are to determine the proportion of systematic reviews that report absolute measures of effect for the most important outcomes, and ascertain how they are analyzed, reported and interpreted.
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Conceptual framework for health-related quality of life assessment in acute gastroenteritis.
J. Pediatr. Gastroenterol. Nutr.
PUBLISHED: 08-28-2013
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To date, most trials in pediatric acute gastroenteritis have evaluated short-term clinical disease activity (eg, duration of diarrhea or vomiting, level of dehydration), laboratory outcomes (eg, rotavirus, norovirus), or a composite of these outcomes. Measuring health-related quality of life may also be important in evaluating the effect of interventions for acute gastroenteritis in children. The objectives of this study were to conduct individual interviews and, when possible, focus group discussions, with parents of children with acute gastroenteritis; to determine how parent and child quality of life is negatively affected by acute gastroenteritis; and, from the perspective of parents and children, to develop a conceptual framework for quality of life instrument specific to pediatric acute gastroenteritis.
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The Quick Mild Cognitive Impairment screen correlated with the Standardized Alzheimers Disease Assessment Scale-cognitive section in clinical trials.
J Clin Epidemiol
PUBLISHED: 07-06-2013
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The Alzheimers Disease Assessment Scale-cognitive section and its standardized version (SADAS-cog) are the current standard for assessing cognitive outcomes in clinical trials of dementia. This study compares a shorter cognitive instrument, the Quick Mild Cognitive Impairment (Qmci) screen, with the SADAS-cog as outcome measures in clinical trials.
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Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children.
Cochrane Database Syst Rev
PUBLISHED: 06-04-2013
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Antibiotics are widely prescribed; however they can cause disturbances in gastrointestinal flora which may lead to reduced resistance to pathogens such as Clostridium difficile (C. difficile). Probiotics are live organisms thought to balance the gastrointestinal flora.
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Opioids for chronic non-cancer pain: a protocol for a systematic review of randomized controlled trials.
Syst Rev
PUBLISHED: 05-14-2013
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Opioids are prescribed frequently and increasingly for the management of chronic non-cancer pain (CNCP). Current systematic reviews have a number of limitations, leaving uncertainty with regard to the benefits and harms associated with opioid therapy for CNCP. We propose to conduct a systematic review and meta-analysis to summarize the evidence for using opioids in the treatment of CNCP and the risk of associated adverse events.
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Combining follow-up and change data is valid in meta-analyses of continuous outcomes: a meta-epidemiological study.
J Clin Epidemiol
PUBLISHED: 02-26-2013
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To investigate whether it is valid to combine follow-up and change data when conducting meta-analyses of continuous outcomes.
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Addressing continuous data for participants excluded from trial analysis: a guide for systematic reviewers.
J Clin Epidemiol
PUBLISHED: 02-25-2013
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No methods directly address the impact of missing participant data for continuous outcomes in systematic reviews on risk of bias.
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Patient-reported outcomes in meta-analyses - part 2: methods for improving interpretability for decision-makers.
Health Qual Life Outcomes
PUBLISHED: 02-11-2013
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Systematic reviews and meta-analyses of randomized trials that include patient-reported outcomes (PROs) often provide crucial information for patients, clinicians and policy-makers facing challenging health care decisions. Based on emerging methods, guidance on improving the interpretability of meta-analysis of patient-reported outcomes, typically continuous in nature, is likely to enhance decision-making. The objective of this paper is to summarize approaches to enhancing the interpretability of pooled estimates of PROs in meta-analyses. When differences in PROs between groups are statistically significant, decision-makers must be able to interpret the magnitude of effect. This is challenging when, as is often the case, clinical trial investigators use different measurement instruments for the same construct within and between individual randomized trials. For such cases, in addition to pooling results as a standardized mean difference, we recommend that systematic review authors use other methods to present results such as relative (relative risk, odds ratio) or absolute (risk difference) dichotomized treatment effects, complimented by presentation in either: natural units (e.g. overall depression reduced by 2.4 points when measured on a 50-point Hamilton Rating Scale for Depression); minimal important difference units (e.g. where 1.0 unit represents the smallest difference in depression that patients, on average, perceive as important the depression score was 0.38 (95%CI 0.30 to 0.47) units less than the control group); or a ratio of means (e.g. where the mean in the treatment group is divided by the mean in the control group, the ratio of means is 1.27, representing a 27%relative reduction in the mean depression score).
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Patient-reported outcomes in meta-analyses--Part 1: assessing risk of bias and combining outcomes.
Health Qual Life Outcomes
PUBLISHED: 02-11-2013
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Systematic reviews and meta-analyses of randomized trials that include patient-reported outcomes (PROs) often provide crucial information for patients and clinicians facing challenging health care decisions. Based on emerging methods, guidance on combining PROs in meta-analysis is likely to enhance their usefulness.The objectives of this paper are: i) to describe PROs and why they are important for health care decision-making, ii) illustrate the key risk of bias issues that systematic reviewers should consider and, iii) address outcome characteristics of PROs and provide guidance for combining outcomes.We suggest a step-by-step approach to addressing issues of PROs in meta-analyses. Systematic reviewers should begin by asking themselves if trials have addressed all the important effects of treatment on patients quality of life. If the trials have addressed PROs, have investigators chosen the appropriate instruments? In particular, does evidence suggest the PROs used are valid and responsive, and is the review free of outcome reporting bias? Systematic reviewers must then decide how to categorize PROs and when to pool results.
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Addressing dichotomous data for participants excluded from trial analysis: a guide for systematic reviewers.
PLoS ONE
PUBLISHED: 01-17-2013
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Systematic reviewer authors intending to include all randomized participants in their meta-analyses need to make assumptions about the outcomes of participants with missing data.
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Probiotics for the prevention of pediatric antibiotic-associated diarrhea.
Cochrane Database Syst Rev
PUBLISHED: 11-11-2011
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Antibiotics alter the microbial balance within the gastrointestinal tract. Probiotics may prevent antibiotic-associated diarrhea (AAD) via restoration of the gut microflora. Antibiotics are prescribed frequently in children and AAD is common in this population.
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Specific instructions for estimating unclearly reported blinding status in randomized trials were reliable and valid.
J Clin Epidemiol
PUBLISHED: 03-01-2011
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To test the reliability and validity of specific instructions to classify blinding, when unclearly reported in randomized trials, as "probably done" or "probably not done."
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Water and sanitation infrastructure for health: The impact of foreign aid.
Global Health
PUBLISHED: 07-29-2010
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The accessibility to improved water and sanitation has been understood as a crucial mechanism to save infants and children from the adverse health outcomes associated with diarrheal disease. This knowledge stimulated the worldwide donor community to develop a specific category of aid aimed at the water and sanitation sector. The actual impact of this assistance on increasing population access to improved water and sanitation and reducing child mortality has not been examined.
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Improving the interpretation of quality of life evidence in meta-analyses: the application of minimal important difference units.
Health Qual Life Outcomes
PUBLISHED: 06-22-2010
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Systematic reviews of randomized trials that include measurements of health-related quality of life potentially provide critical information for patient and clinicians facing challenging health care decisions. When, as is most often the case, individual randomized trials use different measurement instruments for the same construct (such as physical or emotional function), authors typically report differences between intervention and control in standard deviation units (so-called "standardized mean difference" or "effect size"). This approach has statistical limitations (it is influenced by the heterogeneity of the population) and is non-intuitive for decision makers. We suggest an alternative approach: reporting results in minimal important difference units (the smallest difference patients experience as important). This approach provides a potential solution to both the statistical and interpretational problems of existing methods.
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Measurement issues in trials of pediatric acute diarrheal diseases: a systematic review.
Pediatrics
PUBLISHED: 06-21-2010
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Worldwide, diarrheal diseases rank second among conditions that afflict children. Despite the disease burden, there is limited consensus on how to define and measure pediatric acute diarrhea in trials.
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Meta-analyses of safety data: a comparison of exact versus asymptotic methods.
Stat Methods Med Res
PUBLISHED: 11-05-2009
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The objectives of this study were to establish and describe a database of Cochrane and non-Cochrane meta-analyses of safety data and to determine under what conditions exact methods differ from asymptotic methods in meta-analyses of safety data. A sample of Cochrane (n = 500) and non-Cochrane (n = 200) systematic reviews was randomly selected and a database of safety meta-analyses established. Point estimates and confidence intervals for each meta-analysis were recalculated using exact methods and compared to the results of asymptotic methods. Cochrane reviews were nearly four times as likely as non-Cochrane reviews to contain meta-analyses of safety data (35% compared to 9%). More than 50% of safety meta-analyses contained an outcome with a rare event rate (<5%) and 30% contained at least one study with no events in one arm of the study. For rare event meta-analyses, exact point estimates differed substantially from asymptotic estimates 46% of the time, compared to 17% for those without rare events. Exact confidence intervals differed substantially from asymptotic ones 67% of the time compared to only 19% for those without rare events. The magnitude of differences was also correlated with the number of studies and the summary statistic used to combine the data. Asymptotic methods will not always be a good approximation for exact methods in safety meta-analyses. Event rates and number of studies should be closely examined when choosing the statistical method for combining rare event data.
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Subgroup Analysis of Trials Is Rarely Easy (SATIRE): a study protocol for a systematic review to characterize the analysis, reporting, and claim of subgroup effects in randomized trials.
Trials
PUBLISHED: 09-12-2009
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Subgroup analyses in randomized trials examine whether effects of interventions differ between subgroups of study populations according to characteristics of patients or interventions. However, findings from subgroup analyses may be misleading, potentially resulting in suboptimal clinical and health decision making. Few studies have investigated the reporting and conduct of subgroup analyses and a number of important questions remain unanswered. The objectives of this study are: 1) to describe the reporting of subgroup analyses and claims of subgroup effects in randomized controlled trials, 2) to assess study characteristics associated with reporting of subgroup analyses and with claims of subgroup effects, and 3) to examine the analysis, and interpretation of subgroup effects for each studys primary outcome.
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LOST to follow-up Information in Trials (LOST-IT): a protocol on the potential impact.
Trials
PUBLISHED: 03-03-2009
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Incomplete ascertainment of outcomes in randomized controlled trials (RCTs) is likely to bias final study results if reasons for unavailability of patient data are associated with the outcome of interest. The primary objective of this study is to assess the potential impact of loss to follow-up on the estimates of treatment effect. The secondary objectives are to describe, for published RCTs, (1) the reporting of loss to follow-up information, (2) the analytic methods used for handling loss to follow-up information, and (3) the extent of reported loss to follow-up.
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Probiotics for the prevention of Clostridium difficile-associated diarrhea: a systematic review and meta-analysis.
Ann. Intern. Med.
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Antibiotic treatment may disturb the resistance of gastrointestinal flora to colonization. This may result in complications, the most serious of which is Clostridium difficile–associated diarrhea (CDAD).
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GRADE guidelines: 13. Preparing summary of findings tables and evidence profiles-continuous outcomes.
J Clin Epidemiol
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Presenting continuous outcomes in Summary of Findings tables presents particular challenges to interpretation. When each study uses the same outcome measure, and the units of that measure are intuitively interpretable (e.g., duration of hospitalization, duration of symptoms), presenting differences in means is usually desirable. When the natural units of the outcome measure are not easily interpretable, choosing a threshold to create a binary outcome and presenting relative and absolute effects become a more attractive alternative. When studies use different measures of the same construct, calculating summary measures requires converting to the same units of measurement for each study. The longest standing and most widely used approach is to divide the difference in means in each study by its standard deviation and present pooled results in standard deviation units (standardized mean difference). Disadvantages of this approach include vulnerability to varying degrees of heterogeneity in the underlying populations and difficulties in interpretation. Alternatives include presenting results in the units of the most popular or interpretable measure, converting to dichotomous measures and presenting relative and absolute effects, presenting the ratio of the means of intervention and control groups, and presenting the results in minimally important difference units. We outline the merits and limitations of each alternative and provide guidance for meta-analysts and guideline developers.
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Methods to convert continuous outcomes into odds ratios of treatment response and numbers needed to treat: meta-epidemiological study.
Int J Epidemiol
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Clinicians find standardized mean differences (SMDs) calculated from continuous outcomes difficult to interpret. Our objective was to determine the performance of methods in converting SMDs or means to odds ratios of treatment response and numbers needed to treat (NNTs) as more intuitive measures of treatment effect.
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Learning from failure--rationale and design for a study about discontinuation of randomized trials (DISCO study).
BMC Med Res Methodol
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Randomized controlled trials (RCTs) may be discontinued because of apparent harm, benefit, or futility. Other RCTs are discontinued early because of insufficient recruitment. Trial discontinuation has ethical implications, because participants consent on the premise of contributing to new medical knowledge, Research Ethics Committees (RECs) spend considerable effort reviewing study protocols, and limited resources for conducting research are wasted. Currently, little is known regarding the frequency and characteristics of discontinued RCTs.
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Evolution of heterogeneity (I2) estimates and their 95% confidence intervals in large meta-analyses.
PLoS ONE
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Assessment of heterogeneity is essential in systematic reviews and meta-analyses of clinical trials. The most commonly used heterogeneity measure, I(2), provides an estimate of the proportion of variability in a meta-analysis that is explained by differences between the included trials rather than by sampling error. Recent studies have raised concerns about the reliability of I(2) estimates, due to their dependence on the precision of included trials and time-dependent biases. Authors have also advocated use of 95% confidence intervals (CIs) to express the uncertainty associated with I(2) estimates. However, no previous studies have explored how many trials and events are required to ensure stable and reliable I(2) estimates, or how 95% CIs perform as evidence accumulates.
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New methods can extend the use of minimal important difference units in meta-analyses of continuous outcome measures.
J Clin Epidemiol
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For continuous outcomes measured using instruments with an established minimally important difference (MID), pooled estimates can be usefully reported in MID units. Approaches suggested thus far omit studies that used instruments without an established MID. We describe an approach that addresses this limitation.
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Formatting modifications in GRADE evidence profiles improved guideline panelists comprehension and accessibility to information. A randomized trial.
J Clin Epidemiol
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To determine the effects of formatting alternatives in Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evidence profiles on guideline panelists preferences, comprehension, and accessibility.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.