Tarang Sharma was lead-author of a recent article entitled “The Yusuf-Peto method was not a robust method for meta-analyses of rare events data from antidepressant trials”. In this blog, Tarang gives more details about meta-analysis methods of rare events and sparse data, and why these can lead to misleading results.
This blog, written by Leonard Goh, was the winner of Cochrane Malaysia and Penang Medical College’s recent evidence-based medicine blog writing competition. Leonard has written an insightful and informative piece to answer the question: ‘Evidence-based health practice: a fairytale or reality’.
Alina provides a critical appraisal of the ARTEMIDA trial (2015) that assessed efficacy of Actovegin in poststroke cognitive impairment.
This is the fifteenth blog in a series of 34 blogs explaining 34 key concepts we need to be able to understand to think critically about treatment claims.
This blog explains how randomized allocation helps to ensure that the groups have similar characteristics. However, people sometimes do not receive or take the allocated treatments. The characteristics of such people often differ from those who do take the treatment as allocated. Therefore, excluding from the analysis people who did not receive the allocated treatment may mean that like is no longer being compared with like.
This blog provides an introduction to sample size and power; what it is, why it’s important to consider when designing a study, and how to carry out a power calculation.
This is the fourteenth blog in a series of 34 blogs explaining 34 key concepts we need to be able to understand to think critically about treatment claims.
This blog explains that if people in the treatment comparison groups differ in ways other than the treatments being compared, the apparent effects of the treatments might reflect those differences rather than actual treatment effects. A method such as allocating people to different treatments by assigning them random numbers (the equivalent of flipping a coin) is the best way to ensure that the groups being compared are similar in terms of both measured and unmeasured characteristics.
This is the twelfth in a series of 34 blogs explaining 34 key concepts we need to be able to understand to think critically about treatment claims.
This blog explains that large treatment effects (where everyone or nearly everyone treated experiences a benefit or a harm) are easy to detect without fair comparisons, but few treatments have effects that are so large that fair comparisons are not needed.
A pyramid has expressed the idea of hierarchy of medical evidence for so long, that not all evidence is the same. Systematic reviews and meta-analyses have been placed at the top of this pyramid for several good reasons. However, there are several counterarguments to this placement. This blog discusses a new, amended version of the pyramid, proposed in 2016.
A pilot study is a small scale preliminary study conducted in order to evaluate feasibility of the key steps in a future, full-scale project. Pilot studies can teach researchers about any amendments they will need to make to the design of the future study, in order to minimise waste of time and resources.
This blog provides a step-by-step guide on how to conduct a systematic literature search.
This is the seventh in a series of 34 blogs explaining 34 key concepts we need to be able to understand to think critically about treatment claims.
This blog discusses how people with an interest in promoting a treatment (in addition to wanting to help people), such as making money, may promote treatments by exaggerating benefits and ignoring potential harmful effects. Conversely, people may be opposed to a treatment for a range of reasons, such as cultural practices.
This is the sixth in a series of 34 blogs explaining 34 key concepts we need to be able to understand to think critically about treatment claims.
This blog explains that doctors, researchers, patient organisations and other authorities often disagree about the effects of treatments. It explains why we should not rely on the opinions of experts or other authorities about the effects of treatments, unless they clearly base their opinions on the findings of systematic reviews of fair comparisons of treatments.
This is the fourth in a series of 34 blogs explaining 34 key concepts we need to be able to understand to think critically about treatment claims.
This blog explains that treatments that have not been properly evaluated but are widely used or have been used for a long time are often assumed to work. Sometimes, however, they may be unsafe or of doubtful benefit.
This blog is part of the ‘Understanding Evidence’ series, a collaborative series between Cochrane UK and Students 4 Best Evidence. Selena Ryan-Vig, Cochrane UK’s Knowledge and Engagement Officer, takes a look at Cochrane evidence on cocoa and blood pressure and highlights some important considerations when reading research.
This blog provides a detailed overview of the concept of ‘blinding’ in randomised controlled trials (RCTs). It covers what blinding is, common methods of blinding, why blinding is important, and what researchers might do when blinding is not possible. It also explains the concept of allocation concealment.