Browsing by Author "Busse, Jason W."

Now showing 1 - 5 of 5
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    Completion and publication rates of randomized controlled trials in surgery an empirical study
    (2015) Rosenthal, Rachel; Kasenda, Benjamin; Dell-Kuster, Salome; Von Elm, Erik; You, John; Neumann Burotto, Gonzalo Ignacio; Tomonaga, Yuki; Saccilotto, Ramon; Amstutz, Alain; Bengough, Theresa; Meerpohl, Joerg J.; Stegert, Mihaela; Tikkinen, Kari A. O.; Blümle, Anette; Carrasco-Labra, Alonso; Faulhaber, Markus; Mulla, Sohail; Mertz, Dominik; Akl, Elie A.; Bassler, Dirk; Busse, Jason W.; Ferreira-González, Ignacio; Lamontagne, Francois; Nordmann, Alain; Gloy, Viktoria; Olu, Kelechi K.; Raatz, Heike; Moja, Lorenzo; Ebrahim, Shanil; Schandelmaier, Stefan; Sun, Xin; Vandvik, Per O.; Johnston, Bradley C.; Walter, Martin A.; Burnand, Bernard; Schwenkglenks, Matthias; Hemkens, Lars G.; Bucher, Heiner C.; Guyatt, Gordon H.; Briel, Matthias
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    Impact of missing participant data for dichotomous outcomes on pooled effect estimates in systematic reviews: a protocol for a methodological study
    (2014) Akl, Elie A.; Neumann Pohl, Carlos Ignacio.; Kahale, Lara A.; Agarwal, Arnav.; Al-Matari, Nada.; Ebrahim, Shanil.; Alexander, Paul E.; Briel, Matthias.; Brignardello-Petersen, Romina.; Busse, Jason W.
    Abstract Background There is no consensus on how authors conducting meta-analysis should deal with trial participants with missing outcome data. The objectives of this study are to assess in Cochrane and non-Cochrane systematic reviews: (1) which categories of trial participants the systematic review authors consider as having missing participant data (MPD), (2) how trialists reported on participants with missing outcome data in trials, (3) whether systematic reviewer authors actually dealt with MPD in their meta-analyses of dichotomous outcomes consistently with their reported methods, and (4) the impact of different methods of dealing with MPD on pooled effect estimates in meta-analyses of dichotomous outcomes. Methods/Design We will conduct a methodological study of Cochrane and non-Cochrane systematic reviews. Eligible systematic reviews will include a group-level meta-analysis of a patient-important dichotomous efficacy outcome, with a statistically significant effect estimate. Teams of two reviewers will determine eligibility and subsequently extract information from each eligible systematic review in duplicate and independently, using standardized, pre-piloted forms. The teams will then use a similar process to extract information from the trials included in the meta-analyses of interest. We will assess first which categories of trial participants the systematic reviewers consider as having MPD. Second, we will assess how trialists reported on participants with missing outcome data in trials. Third, we will compare what systematic reviewers report having done, and what they actually did, in dealing with MPD in their meta-analysis. Fourth, we will conduct imputation studies to assess the effects of different methods of dealing with MPD on the pooled effect estimates of meta-analyses. We will specifically calculate for each method (1) the percentage of systematic reviews that lose statistical significance and (2) the mean change of effect estimates across systematic reviews. Discussion The impact of different methods of dealing with MPD on pooled effect estimates will help judge the associated risk of bias in systematic reviews. Our findings will inform recommendations regarding what assumptions for MPD should be used to test the robustness of meta-analytical results.
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    Potential impact on estimated treatment effects of information lost to follow-up in randomised controlled trials (LOST-IT): systematic review
    (BMJ PUBLISHING GROUP, 2012) Akl, Elie A.; Briel, Matthias; You, John J.; Sun, Xin; Johnston, Bradley C.; Busse, Jason W.; Mulla, Sohail; Lamontagne, Francois; Bassler, Dirk; Vera, Claudio; Alshurafa, Mohamad; Katsios, Christina M.; Zhou, Qi; Cukierman Yaffe, Tali; Gangji, Azim; Mills, Edward J.; Walter, Stephen D.; Cook, Deborah J.; Schuenemann, Holger J.; Altman, Douglas G.; Guyatt, Gordon H.
    Objective To assess the reporting, extent, and handling of loss to follow-up and its potential impact on the estimates of the effect of treatment in randomised controlled trials.
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    Reporting missing participant data in randomised trials : systematic survey of the methodological literature and a proposed guide
    (2015) Akl, Elie A.; Shawwa, Khled; Kahale, Lara A.; Agoritsas, Thomas; Brignardello Petersen, Romina; Busse, Jason W.; Carrasco Labra, Alonso; Ebrahim, Shanil; Johnston, Bradley C.; Neumann Burotto, Gonzalo Ignacio; Sola, Ivan; Sun, Xin; Vandvik, Per; Zhang, Yuqing; Alonso Coello, Pablo; Guyatt, Gordon H.
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    Specific instructions for estimating unclearly reported blinding status in randomized trials were reliable and valid
    (ELSEVIER SCIENCE INC, 2012) Akl, Elie A.; Sun, Xin; Busse, Jason W.; Johnston, Bradley C.; Briel, Matthias; Mulla, Sohail; You, John J.; Bassler, Dirk; Lamontagne, Francois; Vera, Claudio; Alshurafa, Mohamad; Katsios, Christina M.; Heels Ansdell, Diane; Zhou, Qi; Mills, Ed; Guyatt, Gordon H.
    Objective: 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."