When enough is enough - how to determine when the evidence for the effectiveness of a treatment is sufficient?

The concept of replication in research is widely accepted in most discipline (1); however, there is no consensus about when the evidence is sufficient to confidently state that a treatment works. One good example is a study by Fergusson et al. in 2005 who published a cumulative meta-analysis of the efficacy of Aprotinin to stop bleeding in cardiac surgery (2). They found that the estimates for its effectiveness were consistent after the first 12 studies; nevertheless, an additional 52 similar RCTs were carried out afterwards including more than 5,000 patients.
Source: Osteoarthritis and Cartilage - Category: Rheumatology Authors: Tags: Editorial Source Type: research