Browsing by Author "Bassler, Dirk"

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    Compelling evidence from meta-epidemiological studies demonstrates overestimation of effects in randomized trials that fail to optimize randomization and blind patients and outcome assessors
    (2024) Wang, Ying; Parpia, Sameer; Couban, Rachel; Wang, Qi; Armijo-Olivo, Susan; Bassler, Dirk; Briel, Matthias; Brignardello-Petersen, Romina; Gluud, Lise Lotte; Keitz, Sheri A.; Letelier, Luz M.; Ravaud, Philippe; Schulz, Kenneth F.; Siemieniuk, Reed A. C.; Zeraatkar, Dena; Guyatt, Gordon H.
    Objectives: To investigate the impact of potential risk of bias elements on effect estimates in randomized trials. Study Design and Setting: We conducted a systematic survey of meta-epidemiological studies examining the influence of potential risk of bias elements on effect estimates in randomized trials. We included only meta-epidemiological studies that either preserved the clustering of trials within meta-analyses (compared effect estimates between trials with and without the potential risk of bias element within each meta-analysis, then combined across meta-analyses; between-trial comparisons), or preserved the clustering of substudies within trials (compared effect estimates between substudies with and without the element, then combined across trials; within-trial comparisons). Sepa-rately for studies based on between-and within-trial comparisons, we extracted ratios of odds ratios (RORs) from each study and combined them using a random-effects model. We made overall inferences and assessed certainty of evidence based on Grading of Recommendations, Assessment, development, and Evaluation and Instrument to assess the Credibility of Effect Modification Analyses. Results: Forty-one meta-epidemiological studies (34 of between-, 7 of within-trial comparisons) proved eligible. Inadequate random sequence generation (ROR 0.94, 95% confidence interval [CI] 0.90-0.97) and allocation concealment (ROR 0.92, 95% CI 0.88-0.97) probably lead to effect overestimation (moderate certainty). Lack of patients blinding probably overestimates effects for patient -reported outcomes (ROR 0.36, 95% CI 0.28-0.48; moderate certainty). Lack of blinding of outcome assessors results in effect overesti-mation for subjective outcomes (ROR 0.69, 95% CI 0.51-0.93; high certainty). The impact of patients or outcome assessors blinding on other outcomes, and the impact of blinding of health-care providers, data collectors, or data analysts, remain uncertain. Trials stopped early for benefit probably overestimate effects (moderate certainty). Trials with imbalanced cointerventions may overestimate effects, while trials with missing outcome data may underestimate effects (low certainty). Influence of baseline imbalance, compliance, selective reporting, and intention-to-treat analysis remain uncertain. Conclusion: Failure to ensure random sequence generation or adequate allocation concealment probably results in modest overestimates of effects. Lack of patients blinding probably leads to substantial overestimates of effects for patient-reported outcomes. Lack of blinding of outcome assessors results in substantial effect overestimation for subjective outcomes. For other elements, though evidence for consistent systematic overestimate of effect remains limited, failure to implement these safeguards may still introduce important bias. (c) 2023 Elsevier Inc. All rights reserved.
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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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    Instruments assessing risk of bias of randomized trials frequently included items that are not addressing risk of bias issues
    (2022) Wang, Ying; Ghadimi, Maryam; Wang, Qi; Hou, Liangying; Zeraatkar, Dena; Iqbal, Atiya; Ho, Cameron; Yao, Liang; Hu, Malini; Ye, Zhikang; Couban, Rachel; Armijo-Olivo, Susan; Bassler, Dirk; Briel, Matthias; Gluud, Lise Lotte; Glasziou, Paul; Jackson, Rod; Keitz, Sheri A.; Letelier, Luz M.; Ravaud, Philippe; Schulz, Kenneth F.; Siemieniuk, Reed A. C.; Brignardello-Petersen, Romina; Guyatt, Gordon H.
    Objectives: To establish whether items included in instruments published in the last decade assessing risk of bias of randomized controlled trials (RCTs) are indeed addressing risk of bias.Study Design and Setting: We searched Medline, Embase, Web of Science, and Scopus from 2010 to October 2021 for instruments assessing risk of bias of RCTs. By extracting items and summarizing their essential content, we generated an item list. Items that two re-viewers agreed clearly did not address risk of bias were excluded. We included the remaining items in a survey in which 13 experts judged the issue each item is addressing: risk of bias, applicability, random error, reporting quality, or none of the above.Results: Seventeen eligible instruments included 127 unique items. After excluding 61 items deemed as clearly not addressing risk of bias, the item classification survey included 66 items, of which the majority of respondents deemed 20 items (30.3%) as addressing risk of bias; the majority deemed 11 (16.7%) as not addressing risk of bias; and there proved substantial disagreement for 35 (53.0%) items. Conclusion: Existing risk of bias instruments frequently include items that do not address risk of bias. For many items, experts disagree on whether or not they are addressing risk of bias.(c) 2022 Elsevier Inc. All rights reserved.
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    Maternal outcomes and risk factors for COVID-19 severity among pregnant women
    (2021) Vouga, Manon; Favre, Guillaume; Pomar, Leo; Forcen Acebal, Laura; Abascal-Saiz, Alejandra; Vila Hernandez, Maria Rosa; Hcini, Najeh; Lambert, Veronique; Carles, Gabriel; Sichitiu, Joanna; Salomon, Laurent; Stirnemann, Julien; Ville, Yves; de Tejada, Begona Martinez; Gonce, Anna; Castillo, Karen; Gratacos Solsona, Eduard; Trigo, Lucas; Cleary, Brian; Geary, Michael; Bartels, Helena; Malone, Fergal; Higgins, Mary; Keating, Niamh; Knowles, Susan; Poncelet, Christophe; Surita, Fernanda; Borrelli, Carolina; Luz, Adriana Gomes; Fuenzalida, Javiera; Carvajal, Jorge; Guerra Canales, Manuel; Hernandez, Olivia; Grechukhina, Olga; Ko, Albert, I; Reddy, Uma; Figueiredo, Rita; Moucho, Marina; Pinto, PedroViana; De Luca, Carmen; De Santis, Marco; de Campos, Diogo Ayres; Martins, Ines; Garabedian, Charles; Subtil, Damien; Bohrer, Betania; Da Rocha Oppermann, Maria Lucia; OsorioWender, Maria Celeste; Vieira Sanseverino, Maria Teresa; Giugliani, Camila; Friedrich, Luciana; Scherer, Mariana Horn; Mottet, Nicolas; Ducarme, Guillaume; Pelerin, Helene; Moreau, Chloe; Breton, Benedicte; Quibel, Thibaud; Rozenberg, Patrick; Giannoni, Eric; Granado, Cristina; Monod, Cecile; Mueller, Doris; Hoesli, Irene; Bassler, Dirk; Heldstab, Sandra; Kolble, Nicole Ochsenbein; Sentilhes, Loic; Charvet, Melissa; Deprest, Jan; Richter, Jute; Van der Veeken, Lennart; Eggel-Hort, Beatrice; Plantefeve, Gaetan; Derouich, Mohamed; Nieto Calvache, Albaro Jose; Hecher, Kurt; Hadar, Eran; Haratz, Karina Krajden; Amikam, Uri; Malinger, Gustavo; Maymon, Ron; Yogev, Yariv; Schafer, Leonhard; Toussaint, Arnaud; Rossier, Marie-Claude; De Sa, RenatoAugusto Moreira; Grawe, Claudia; Aebi-Popp, Karoline; Raio, Luigi; Surbek, Daniel; Bockenhof, Paul; Strizek, Brigitte; Kaufmann, Martin; Bloch, Andrea; Boulvain, Michel; Johann, Silke; Heldstab, SandraAndrea; Bernasconi, MonyaTodesco; Grant, Gaston; Feki, Anis; Muller Brochut, Anne-Claude; Giral, Marylene; Sedille, Lucie; Papadia, Andrea; Brugger, Romina Capoccia; Weber, Brigitte; Fischer, Tina; Kahlert, Christian; Saines, Karin Nielsen; Cambou, Mary; Kanellos, Panagiotis; Chen, Xiang; Yin, Mingzhu; Haessig, Annina; Ackermann, Sandrine; Baud, David; Panchaud, Alice
    Pregnant women may be at higher risk of severe complications associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which may lead to obstetrical complications. We performed a case control study comparing pregnant women with severe coronavirus disease 19 (cases) to pregnant women with a milder form (controls) enrolled in the COVI-Preg international registry cohort between March 24 and July 26, 2020. Risk factors for severity, obstetrical and immediate neonatal outcomes were assessed. A total of 926 pregnant women with a positive test for SARS-CoV-2 were included, among which 92 (9.9%) presented with severe COVID-19 disease. Risk factors for severe maternal outcomes were pulmonary comorbidities [aOR 4.3, 95% CI 1.9-9.5], hypertensive disorders [aOR 2.7, 95% CI 1.0-7.0] and diabetes [aOR2.2, 95% CI 1.1-4.5]. Pregnant women with severe maternal outcomes were at higher risk of caesarean section [70.7% (n=53/75)], preterm delivery [62.7% (n=32/51)] and newborns requiring admission to the neonatal intensive care unit [41.3% (n=31/75)]. In this study, several risk factors for developing severe complications of SARS-CoV-2 infection among pregnant women were identified including pulmonary comorbidities, hypertensive disorders and diabetes. Obstetrical and neonatal outcomes appear to be influenced by the severity of maternal disease.
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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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    Premature Discontinuation of Pediatric Randomized Controlled Trials: A Retrospective Cohort Study
    (2017) Schandelmaier, Stefan; Tomonaga, Yuki; Bassler, Dirk; Meerpohl, Joerg J.; Von Elm, Erik; You, John J.; Bluemle, Anette; Lamontagne, Francois; Saccilotto, Ramos; Neumann Burotto, Gonzalo Ignacio
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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."