Evidence synthesis is a type of secondary research which uses a rigorous and transparent methodology to select and analyse available data from multiple sources to identify knowledge gaps and establish the best decision across health, public health and social care. This methodology is often standardised and guided by the best tools and resources, such as Prism Guidelines, Joanna Briggs Institute (JBI ) tool, CASP etc. Using the transparent method; researchers can ensure consistency, replicability, and minimal bias to produce results.
Researchers can conduct various kinds of Evidence Synthesis, depending upon the requirement :
Systematic Reviews: Systematic review can be characterised as a replicable technique for integrating information as per responsible, pre-planned criteria. This includes three distinct features: recognising important sources, assessing research, and combining proof.(Gough, Oliver &Thomas, 2017).It can be done with or without meta-analysis.
Rapid Reviews: This type of review uses a streamlined method to get the answer when needed quickly.
Scooping Reviews: This type of review can be done to know the existing studies’ nature, features and volume without looking at the findings in detail.
Statistical Analysis: Evidence synthesis may include statistical analysis such as meta-analysis or network meta-analysis to combine individual study results. Gene V Glass coined the term meta-analysis, describing it as an “analysis of analyses”
Meta-analysis: is a quantitative, formal, epidemiological examination that systematically evaluates past research studies and determines decisions about that group. In simple terms, meta-analyses aim to combine results from previous studies quantitatively. Results from a meta-examination may incorporate a more exact gauge of the impact of treatment or hazard factors for illness or other outcomes than any individual investigation adding to the pooled analysis (Haidich, 2010).
Network meta-analysis: As per Valkenhoef et al; 2012 it is known as mixed–treatment comparison meta-analysis. Various direct and indirect treatment comparisons are integrated into a model that can be formalised as a comparison “network”
Decision Analytic Modeling : This analysis estimates the costs, outcomes and cost-effectiveness of various health and public health interventions and programmes. Henceforth, this model determines much funding for the health system by assessing the value of new pharmaceuticals.
Aim and Objectives
The aim and Objectives of any centre conducting evidence synthesis are to emphasise evidence at the heart of health and care decision-making in the specific country. The objective like producing highly trusted synthesised evidence addressing critical health and care decision-making questions and making the evidence accessible and available to inform health and care policy would support the aim. In other words, the four pillars of collaboration, relevance, integrity and quality would go hand in hand to achieve the goal of any centre conducting evidence synthesis.
The Importance of Evidence Synthesis
There are many organisations in the world, such as Cochrane Collaboration, Campbell Collaboration, Eppi Centre, and Health Evidence Network; WHO etc, which have dedicated teams that span various types of evidence synthesis, which helps to determine the effectiveness of the drugs, people experience on multiple health conditions and treatments, the cost-effectiveness of the treatment etc. By using evidence synthesis effectively, not only health professionals like doctors and researchers can make the best decisions about health and health care but the general public would have the same choice. Furthermore, the trend of scientific publication on health research is increasing worldwide, henceforth the published information must be assessed if the publication is accurate, trustworthy and unbiased.
References :
Ab, H. (2010). Meta-analysis in medical research. In HIPPOKRATIA (Vol. 2010, Issue 1). http://scholar.google.com
Glass V Gene. (1976). Primary,Secondary and Meta-Analysis of Research. Sage Publication.
Gough David, Oliver Sandy, & Thomas James. (2017). Intro to Sys Reviews. Sage Publication.
Valkenhoef Van, Lu Guobing, Brock Bert de, Hillege Hans, Ades A E, & Welton Nicky. (2012). Automating network meta-analysis. Pubmed. https://pubmed.ncbi.nlm.nih.gov/26053422/
© 2024 Dr Mukta Bhattarai Pandey (MD, PGDip Public Health, MRCP(UK), MRes)