Systematic Reviews
Health care decisions for individual patients and for public policy should be informed by the best available research evidence. Practitioners and decision-makers are encouraged to make use of the latest research and information about best practice, and to ensure that decisions are rooted in this knowledge.
However, this can be difficult given the large amounts of information generated by individual studies which may be biased, methodologically flawed, time and context dependent, and can be misinterpreted and misrepresented. Furthermore, individual studies can reach conflicting conclusions because of biases or differences in the way the studies were designed or conducted, or simply due to the play of chance. In such situations, it is not always clear which results are the most reliable, or which should be used as the basis for practice and policy decisions.
Systematic reviews aim to identify, evaluate and summarise the findings of all relevant individual studies, thereby making the available evidence more accessible to decision-makers. When appropriate, combining the results of several studies gives a more reliable and precise estimate of an intervention’s effectiveness than one study alone.
Systematic reviews adhere to a strict scientific design based on explicit, pre-specified and reproducible methods. Because of this, when carried out well, they provide reliable estimates about the effects of interventions so that conclusions are defensible. As well as setting out what we know about a particular intervention, systematic reviews can also demonstrate where knowledge is lacking. This can then be used to guide future research.
CRD produces systematic reviews evaluating the research evidence on health and public health questions that have impacted on policy and practice. In addition, CRD’s guidance on how to undertake a systematic review is widely recommended and used both nationally and internationally.
