Elie A Akl1, Lara A Kahale2, Shanil Ebrahim3, Pablo Alonso-Coello4, Holger J Schünemann5, Gordon H Guyatt5. 1. Department of Internal Medicine, American University of Beirut, Riad-El-Solh Beirut 1107, Beirut 2020, Lebanon; Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main St W, Hamilton, Ontario L8S 4L8, Canada. Electronic address: ea32@aub.edu.lb. 2. Department of Internal Medicine, American University of Beirut, Riad-El-Solh Beirut 1107, Beirut 2020, Lebanon. 3. Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main St W, Hamilton, Ontario L8S 4L8, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, 27 King's College Cir, Toronto, Ontario M5S, Canada; Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, University Of Toronto, 27 King's College Cir, Toronto, Ontario M5S, Canada; Department of Medicine, Stanford University, 450 Serra Mall, Stanford, CA 94305, USA. 4. Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau (CIBERESP-IIB Sant Pau), Pavelló 18 Planta 0 Sant Antoni M Claret 167 08025, Barcelona, Spain. 5. Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main St W, Hamilton, Ontario L8S 4L8, Canada; Department of Medicine, McMaster University, 1280 Main St W, Hamilton, Ontario L8S 4L8, Canada.
Abstract
OBJECTIVE: To categorize the challenges in determining the extent of missing participant data in randomized trials and suggest potential solutions for systematic review authors. STUDY DESIGN AND SETTING: During the process of updating a series of Cochrane systematic reviews on the topic of anticoagulation in patients with cancer, we identified challenges and used an iterative approach to improve, and a consensus process to agree on the challenges identified, and to suggest potential ways of dealing with them. The five systematic reviews included 58 trials and 75 meta-analyses for patient-important dichotomous outcomes with 27,037 randomized participants. RESULTS: We identified three categories of challenges: (1) Although systematic reviewers require information about missing data to be reported by outcome, trialists typically report the information by participant; (2) It is not always clear whether the trialists followed up participants in certain categories (e.g., noncompliers), that is, whether some categories of participants did or did not have missing data; (3) It is not always clear how the trialists dealt with missing data in their analysis (e.g., exclusion from the denominator vs. assumptions made for the numerator). We discuss potential solutions for each one of these challenges and suggest further research work. CONCLUSION: Current reporting of missing data is often not explicit and transparent, and although our potential solutions to problems of suboptimal reporting may be helpful, reliable and valid characterization of the extent and nature of missing data remains elusive. Reporting of missing data in trials needs further improvement.
OBJECTIVE: To categorize the challenges in determining the extent of missing participant data in randomized trials and suggest potential solutions for systematic review authors. STUDY DESIGN AND SETTING: During the process of updating a series of Cochrane systematic reviews on the topic of anticoagulation in patients with cancer, we identified challenges and used an iterative approach to improve, and a consensus process to agree on the challenges identified, and to suggest potential ways of dealing with them. The five systematic reviews included 58 trials and 75 meta-analyses for patient-important dichotomous outcomes with 27,037 randomized participants. RESULTS: We identified three categories of challenges: (1) Although systematic reviewers require information about missing data to be reported by outcome, trialists typically report the information by participant; (2) It is not always clear whether the trialists followed up participants in certain categories (e.g., noncompliers), that is, whether some categories of participants did or did not have missing data; (3) It is not always clear how the trialists dealt with missing data in their analysis (e.g., exclusion from the denominator vs. assumptions made for the numerator). We discuss potential solutions for each one of these challenges and suggest further research work. CONCLUSION: Current reporting of missing data is often not explicit and transparent, and although our potential solutions to problems of suboptimal reporting may be helpful, reliable and valid characterization of the extent and nature of missing data remains elusive. Reporting of missing data in trials needs further improvement.
Authors: Lara A Kahale; Maram B Hakoum; Ibrahim G Tsolakian; Charbel F Matar; Maddalena Barba; Victor E D Yosuico; Irene Terrenato; Francesca Sperati; Holger Schünemann; Elie A Akl Journal: Cochrane Database Syst Rev Date: 2017-12-29
Authors: Lara A Kahale; Charbel F Matar; Ibrahim Tsolakian; Maram B Hakoum; Maddalena Barba; Victor Ed Yosuico; Irene Terrenato; Francesca Sperati; Holger Schünemann; Elie A Akl Journal: Cochrane Database Syst Rev Date: 2021-10-08
Authors: Lara A Kahale; Charbel F Matar; Ibrahim Tsolakian; Maram B Hakoum; Victor Ed Yosuico; Irene Terrenato; Francesca Sperati; Maddalena Barba; Lisa K Hicks; Holger Schünemann; Elie A Akl Journal: Cochrane Database Syst Rev Date: 2021-09-28
Authors: Lara A Kahale; Maram B Hakoum; Ibrahim G Tsolakian; Charbel F Matar; Irene Terrenato; Francesca Sperati; Maddalena Barba; Victor Ed Yosuico; Holger Schünemann; Elie A Akl Journal: Cochrane Database Syst Rev Date: 2018-06-19
Authors: Lara A Kahale; Ibrahim G Tsolakian; Maram B Hakoum; Charbel F Matar; Maddalena Barba; Victor Ed Yosuico; Irene Terrenato; Francesca Sperati; Holger Schünemann; Elie A Akl Journal: Cochrane Database Syst Rev Date: 2018-06-01
Authors: Maram B Hakoum; Lara A Kahale; Ibrahim G Tsolakian; Charbel F Matar; Victor Ed Yosuico; Irene Terrenato; Francesca Sperati; Maddalena Barba; Holger Schünemann; Elie A Akl Journal: Cochrane Database Syst Rev Date: 2018-01-24
Authors: Lara A Kahale; Charbel F Matar; Maram B Hakoum; Ibrahim G Tsolakian; Victor Ed Yosuico; Irene Terrenato; Francesca Sperati; Maddalena Barba; Holger Schünemann; Elie A Akl Journal: Cochrane Database Syst Rev Date: 2021-12-08
Authors: Elie A Akl; Lara A Kahale; Maram B Hakoum; Charbel F Matar; Francesca Sperati; Maddalena Barba; Victor E D Yosuico; Irene Terrenato; Anneliese Synnot; Holger Schünemann Journal: Cochrane Database Syst Rev Date: 2017-09-11
Authors: Charbel F Matar; Lara A Kahale; Maram B Hakoum; Ibrahim G Tsolakian; Itziar Etxeandia-Ikobaltzeta; Victor Ed Yosuico; Irene Terrenato; Francesca Sperati; Maddalena Barba; Holger Schünemann; Elie A Akl Journal: Cochrane Database Syst Rev Date: 2018-07-11