A meta-analysis is a statistical procedure for combining numerical data from multiple separate studies. A meta-analysis should only ever be conducted in the context of a systematic review .
Are all meta-analysis systematic reviews?
This is called meta-analysis, and it represents a specialized subset of systematic reviews. Not all systematic reviews include meta-analysis, but all meta-analyses are found in systematic reviews .
Can you have a meta analysis without a systematic review?
Sometimes if you have access to the numerical data you may not have to do a systematic review. For example some drug companies run trials and have the data so they run a meta-analysis without doing a systematic review. So: 1) There are many systematic reviews without performing a meta-analysis.
Is a meta-analysis the same as a systematic review?
A systematic review attempts to gather all available empirical research by using clearly defined, systematic methods to obtain answers to a specific question. A meta-analysis is the statistical process of analyzing and combining results from several similar studies .
When should you not do a meta-analysis?
Meta-analyses of studies that are at risk of bias may be seriously misleading. If bias is present in each (or some) of the individual studies, meta-analysis will simply compound the errors, and produce a ‘wrong’ result that may be interpreted as having more credibility.
What are the disadvantages of meta-analysis?
Additionally, meta-analyses can be poorly executed. Carelessness in abstracting and summarizing appropriate studies , failure to consider important covariates, bias on the part of the meta-analyst and overstatements of the strength and precision of the results can all contribute to invalid meta-analyses.
What is the difference between a literature review and a meta-analysis?
A Literature review is the analysis of all existing literature in a field of study. ... Meta Analysis, on the other hand, is an analysis of similar scientific studies to establish an estimate closest to the common point of truth that exist between them .
How do you tell if a paper is a meta-analysis?
In most Library databases, you can find meta-analysis research articles by using meta analysis as a search term . There are a few databases that have special limiters for publication type or methodology in the advanced searching section.
What is an example of meta-analysis?
For example, a systematic review will focus specifically on the relationship between cervical cancer and long-term use of oral contraceptives , while a narrative review may be about cervical cancer. Meta-analyses are quantitative and more rigorous than both types of reviews.
How many studies do you need in a meta-analysis?
Two studies is a sufficient number to perform a meta-analysis, provided that those two studies can be meaningfully pooled and provided their results are sufficiently ‘similar’.
Is it hard to do a meta-analysis?
Although meta-analysis is becoming evermore popular, it can be difficult to undertake without the guidance of an experienced meta-analyst . However, if one is motivated and has a good statistics background, even a novice can perform a meta-analysis.
What is the main purpose of a meta-analysis?
Meta-analyses are conducted to assess the strength of evidence present on a disease and treatment . One aim is to determine whether an effect exists; another aim is to determine whether the effect is positive or negative and, ideally, to obtain a single summary estimate of the effect.
What are the problems with meta-analysis?
Several problems arise in meta-analysis: regressions are often non-linear ; effects are often multivariate rather than univariate; coverage can be restricted; bad studies may be included; the data summarised may not be homogeneous; grouping different causal factors may lead to meaningless estimates of effects; and the ...
What is the advantage of using a meta-analysis?
Meta-analysis provides a more precise estimate of the effect size and increases the generalizability of the results of individual studies . Therefore, it may enable the resolution of conflicts between studies, and yield conclusive results when individual studies are inconclusive.
What are the disadvantages of review and meta-analysis?
The main limitations that can affect systematic reviews are publication bias (and others similar as language bias) , bias risks in primary studies (methodological limitation of primary studies), and difficulties in combining studies that may have differences in populations, interventions, comparators and definition of ...
