Addressing continuous data for participants excluded from trial analysis: a guide for systematic reviewers
Por:
Ebrahim, S, Akl, EA, Mustafa, RA, Sun, X, Walter, SD, Heels-Ansdell, D, Alonso-Coello, P, Johnston, BC, Guyatt, GH
Publicada:
1 sep 2013
Resumen:
Background: No methods directly address the impact of missing participant data for continuous outcomes in systematic reviews on risk of bias.
Methods: We conducted a consultative, iterative process to develop a framework for handling missing participant data for continuous outcomes. We considered sources reflecting real observed outcomes in participants followed-up in individual trials included in the systematic review, and developed a range of plausible strategies. We applied our approach to two systematic reviews.
Results: We used five sources of data for imputing the means for participants with missing data. To impute standard deviation (SD), we used the median SD from the control arms of all included trials. Using these sources, we developed four progressively more stringent imputation strategies. In the first example review, effect estimates diminished and lost significance as strategies became more stringent, suggesting rating down confidence in estimates of effect for risk of bias. In the second, effect estimates maintained statistical significance using even the most stringent strategy, suggesting missing data does not undermine confidence in results.
Conclusions: Our approach provides a useful, reasonable, and relatively simple, quantitative guidance for judging the impact of risk of bias as a result of missing participant data in systematic reviews of continuous outcomes. (C) 2013 Elsevier Inc. All rights reserved.
Filiaciones:
Ebrahim, S:
McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
McMaster Univ, Dept Anesthesia, Hamilton, ON L8S 4K1, Canada
Akl, EA:
McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
Amer Univ Beirut, Dept Internal Med, Beirut 11072020, Lebanon
SUNY Buffalo, Dept Med, Buffalo, NY 14215 USA
Mustafa, RA:
McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
Univ Missouri, Dept Med, Kansas City, MO 64110 USA
Sun, X:
McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
Xinqiao Hosp, Ctr Clin Epidemiol & Evidence Based Med, Chongqing, Peoples R China
Walter, SD:
McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
Heels-Ansdell, D:
McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
Alonso-Coello, P:
CIBERESP IIB St Pau, Iberoamer Cochrane Ctr, Barcelona 08025, Spain
Johnston, BC:
McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
Univ Toronto, Inst Hlth Policy Management & Evaluat, Toronto, ON M5T 3M6, Canada
Hosp Sick Children, Dept Anesthesia & Pain Med, Toronto, ON M5G 1X8, Canada
SickKids Res Inst, Toronto, ON M5G 1X8, Canada
Guyatt, GH:
McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
McMaster Univ, Dept Med, Hamilton, ON L8S 4K1, Canada
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