Article type
Year
Abstract
Background: our team is working on several prognostic factor systematic reviews (SR). A SR aiming to determine the independent prognostic role of a factor must come from a structured question (population, index factor, comparator, outcomes, timeframe and study design). The definition of the comparator requires identification of additional prognostic factors for which the prognostic association should be adjusted. Ideally, these key additional prognostic factors should be defined at the protocol stage of the SR.
Objectives: to describe the procedure that we followed to select the additional prognostic factors in the Cochrane Review protocol titled, 'Sex as a prognostic factor in patients with acute symptomatic pulmonary embolism'.
Methods: we carried out a bibliographic search in PubMed and Embase to identify prognostic factors in acute pulmonary embolism (PE). This search retrieved six factors, which we compiled in GRADEpro-GDT. We sent the list to the SR team. In this first stage, the team commented on the factors already listed or added new ones. A total of 24 factors were compiled. In the second stage, the review team prioritised these factors, ranking them from 1 to 9 (with 1 being of least importance and 9 the highest). There was also the option to choose 'unknown'. Once all the team members had finished ranking, they were asked to confirm the list of factors and the order in which they had been prioritised.
Results: we classified the additional prognostic factors into three groups of factors: high priority (5), low priority (9), and excluded (10). The five high priority factors chosen were: immobilization history, history of surgery, history of recent bleeding, PESI score, and simplified PESI score.
Strengths: 1) our approach is transparent; 2) the process is straightforward in GRADEPro-GDT and doesn’t require people to attend meetings; 3) this process highlights the need to define an evidence-based procedure to define the list of additional confounders, which may be applied to any SR including non-randomised designs.
Limitations: 1) the criteria to define the relevance of the additional prognostic factors relied on clinical judgement only; however, there should be an evidence-based approach in place (for example, the additional adjustment factors should be statistically associated with both the outcome and the prognostic factor, and should not lie on a direct pathway between the prognostic factor and the outcome); 2) the maximum number of additional prognostic factors isn't defined and to limit the number is not simple.
Conclusions: we applied a transparent procedure for selecting additional prognostic factors to consider in a prognostic factor SR. This procedure can be applied to SR of prognostic factor studies in the future. However, more research is needed to define the criteria on which to base decisions to select the additional prognostic factors or the maximum number of factors to select.
Objectives: to describe the procedure that we followed to select the additional prognostic factors in the Cochrane Review protocol titled, 'Sex as a prognostic factor in patients with acute symptomatic pulmonary embolism'.
Methods: we carried out a bibliographic search in PubMed and Embase to identify prognostic factors in acute pulmonary embolism (PE). This search retrieved six factors, which we compiled in GRADEpro-GDT. We sent the list to the SR team. In this first stage, the team commented on the factors already listed or added new ones. A total of 24 factors were compiled. In the second stage, the review team prioritised these factors, ranking them from 1 to 9 (with 1 being of least importance and 9 the highest). There was also the option to choose 'unknown'. Once all the team members had finished ranking, they were asked to confirm the list of factors and the order in which they had been prioritised.
Results: we classified the additional prognostic factors into three groups of factors: high priority (5), low priority (9), and excluded (10). The five high priority factors chosen were: immobilization history, history of surgery, history of recent bleeding, PESI score, and simplified PESI score.
Strengths: 1) our approach is transparent; 2) the process is straightforward in GRADEPro-GDT and doesn’t require people to attend meetings; 3) this process highlights the need to define an evidence-based procedure to define the list of additional confounders, which may be applied to any SR including non-randomised designs.
Limitations: 1) the criteria to define the relevance of the additional prognostic factors relied on clinical judgement only; however, there should be an evidence-based approach in place (for example, the additional adjustment factors should be statistically associated with both the outcome and the prognostic factor, and should not lie on a direct pathway between the prognostic factor and the outcome); 2) the maximum number of additional prognostic factors isn't defined and to limit the number is not simple.
Conclusions: we applied a transparent procedure for selecting additional prognostic factors to consider in a prognostic factor SR. This procedure can be applied to SR of prognostic factor studies in the future. However, more research is needed to define the criteria on which to base decisions to select the additional prognostic factors or the maximum number of factors to select.
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