Browsing by Author "Brignardello-Petersen, Romina."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    The GRADE evidence-to-decision framework: a report of its testing and application in 15 international guideline panels
    (2016) Neumann Burotto, Gonzalo Ignacio; Brignardello-Petersen, Romina.; Wiercioch, Wojtek.; Carrasco-Labra, Alonso.; Cuello, Carlos.; Akl, Elie A.; Mustafa, Reem A.; Al-Hazzani, Waleed.; Etxeandia-Ikobaltzeta, Itziar.; Rojas, Maria Ximena.
    Abstract Background Judgments underlying guideline recommendations are seldom recorded and presented in a systematic fashion. The GRADE Evidence-to-Decision Framework (EtD) offers a transparent way to record and report guideline developers’ judgments. In this paper, we report the experiences with the EtD frameworks in 15 real guideline panels. Methods Following the guideline panel meetings, we asked methodologists participating in the panel to provide feedback regarding the EtD framework. They were instructed to consider their own experience and the feedback collected from the rest of the panel. Two investigators independently summarized the responses and jointly interpreted the data using pre-specified domains as coding system. We asked methodologists to review the results and provide further input to improve the structure of the EtDs iteratively. Results The EtD framework was well received, and the comments were generally positive. Methodologists felt that in a real guideline panel, the EtD framework helps structuring a complex process through relatively simple steps in an explicit and transparent way. However, some sections (e.g., “values and preferences” and “balance between benefits and harms”) required further development and clarification that were considered in the current version of the EtD framework. Conclusions The use of an EtD framework in guideline development offers a structured and explicit way to record and report the judgments and discussion of guideline panels during the formulation of recommendations. In addition, it facilitates the formulation of recommendations, assessment of their strength, and identifying gaps in research.