Clinical research writing services 
                     What is the Difference between
A S YS TEM ATIC  
REVIEW AND A 
M ETA-  ANALYSIS?
An Academic presentation by
Dr. Nancy Agnes, Head, Technical 
Operations, Pubrica  Group:
www.pubrica.com
Email: [email protected]
TODAY 'S
D I S C U S S I O N
In Brief
Introduction
The stages of systematic review
Why don't all systemic reviews use meta-
analysis?  What does meta-analysis do?
What are the other ways to synthesize 
evidence?  Conclusion
About Pubrica
IN  BRIEF
The terms systematic review and meta-analysis are also used  
interchangeably. Each term refers to research about the study, 
but  there are significant variations between them.
A systematic review is a part of the work that poses a study 
question  and then responds by summarising the evidence that 
satisfies a  collection of pre-determined requirements.
A meta-analysis, a statistical implement for combining the 
results of  
many trials to produce an average outcome, is used in some s
ystematic  review writing to present their findings.
In addition, meta-analysis provides value because it can 
provide a more  accurate estimation of a treatment's impact 
than looking at each study  separately.
INTRODUCTION
A systematic review is a method of collecting,  
evaluating, and synthesizing evidence to 
address a  well-defined question that is 
comprehensive,  systematic, and clear.
A meta-analysis is a statistical method for 
integrating  numerical data from different 
studies into a single  report. Only a systematic 
review should ever be used to  perform a meta-
analysis.
Systematic reviews and meta-analyses combine 
and  analyze data from various studies on 
related research  subjects to present findings. In 
recent years, systematic  reviews and meta-
analyses have become common in  various 
fields, including anesthesiology.
Contd...
These research approaches are effective tools for overcoming the challenges of large-
scale  randomized controlled trials.
However, systematic reviews and meta-analyses, including studies with biases or 
inappropriately  measured quality of evidence, may lead to misleading results. As a 
result, different standards for  conducting systematic review evaluations and meta-
analyses have been proposed to standardize  them further and improve their quality.
Systematic evaluations are distinguished by their efforts to eliminate bias at all levels 
of the review  process. The following are the steps involved in undertaking a review:
1. Identify your issue and, preferably, register the title of your proposed study.
2.Specify and publish your suggested approach as a protocol in advance.
3.Conduct a systematic literature quest.
4. Review your search results against your pre-determined selection criteria to find 
studies that  should be included.
5.Evaluate the consistency of the studies discovered
6.Compile the proof, which may or may not include a meta-analysis.
7.Make the analysis public by publishing and disseminating it.
8.Keep the study up to date as new information becomes available.
THE S T A G E S  OF S Y S T E M A T I C  
 REV IEW
A research question and a protocol or research 
plan  are the foundations of a systematic 
analysis. Using a  compassionate search 
approach, a research team  looks for studies to 
address the issue.
The recovered studies are then screened for 
eligibility  (this is done by at least two people 
working  independently). The reviewers then 
extract the  relevant data and determine the 
validity of the studies  that have been included. 
Finally, the research team  synthesizes the data 
from the various studies  (possibly using meta-
analysis) and presents the  findings.
Identify the research question
Extract data
Define inclusion and exclusion 
Assess quality
criteria  Search for studies
Synthesize and present 
Select studies results
The stages of systematic 
review
Systematic  
Review and  Case 
meta- reports
analysis
Cohort studies In Vitro  
Researc
h
Randomized  Ideas,  
controlled editorials
double  blind test ,  
opinions
Case 
control  
studies
Animal  
Researc
h
Case series
lity of
Eidence
Qua v
A systematic review gathers all relevant research on a specific subject and design, then 
summarises 
 
and analyses their findings. The quality of studies is assessed during the systematic revi
ew phase, 
 and the research findings are statistically meta-analyzed based on their quality.
A meta-analysis is a method of interpreting and integrating various accurate, analytical,
 and  
empirical results. A meta-analysis is usually performed on randomized controlled trials (
RCTs) with a 
 high degree of evidence to obtain more accurate findings.
WHY DON'T ALL S Y S T E M A T I C
REV IEWS  USE  M E T A - AN A L Y S I S ?
The accuracy of an impact estimation can be 
improved  with meta-analysis. However, it can be 
deceiving if done  with data that are not equally 
identical or with low  methodological consistency 
(for example, because the  study participants 
were not properly randomized).
As a result, meta-analysis isn't always sufficient, 
and  many systematic reviews don't involve it. 
Even if there is  no meta-analysis in the review, it 
can still synthesize  study data to create 
something more valuable than the  sum of its 
parts.
WHAT D OE S  META-  
 A N A L Y S I S  DO?
Meta-analysis produces a more accurate 
treatment  impact calculation. The evaluation 
committee  determined the most appropriate 
type of effect size  based on the kind of results 
and measures under  consideration.
The odds ratio, risk ratio, weighted mean 
difference,  and standardized mean difference 
are standard effect  sizes in systematic reviews.
For example, a forest map, such as the one 
shown  
below, is used to represent the effects of writin
g a  meta-analysis paper.
Figure: Forest plots display the estimated results from a group of studies plus a 
summary
Subgroup analysis or meta-regression was used in several meta-analysis writing
 services.
These strategies are used to investigate a factor (such as the age of the research 
participant) that  can affect the treatment-intervention relationship.
To prevent bias, plans for analyzing data using these techniques should be explained 
and justified  before looking at the data, preferably during the research plan or protocol 
level.
Subgroup analysis and meta-regression, like meta-analysis, are only helpful in such 
situations.
WHAT ARE  THE OTHER 
 W A Y S  TO 
S Y N T H E S I Z E   
ESVystIeDmaEticN reCvieEws? combine research data in 
various  ways to arrive at a comprehensive 
picture of the proof.  Meta-analysis is a 
mathematical synthesis technique.  The results of 
several studies are combined using terms  in a 
narrative synthesis. All systematic reviews, 
including  those that use meta-analysis, are likely 
to include a  narrative synthesis component, 
which summarises the  evidence in words.
However, narrative synthesis aims to clarify the  
gathered data, for example, by examining 
similarities  and differences between study 
findings and investigating  potential explanations 
for those similarities and  differences 
systematically.
CONCLUS ION
Suppose the validity of research is not adequately 
assessed, or  proper protocol is not strictly followed when 
conducting a  systematic review or meta-analysis.
In that case, the findings can be biased, and the 
outcomes can be  wrong. When systematic reviews and 
meta-analyses are properly  applied, they can produce 
powerful results that are usually only  possible with large-
scale clinical trials, which are challenging to  conduct in 
individual studies.
The number of systematic reviews and meta-analyses will 
continue  to rise as our understanding of evidence-based 
medicine improves  and its relevance is better understood. 
However, blind acceptance  of both meta-analyses can be 
harmful, so we suggest that their  findings be viewed 
critically based on a better understanding.
ABOUT PUBR ICA
Pubrica's research team creates scientific and 
medical  research articles that clinical 
meta-analysis experts and  authors can use 
as a resource.
Pubrica medical writers assist you in writing and edi
ting the 
 
introduction by informing the reader of any flaws or 
blank 
 spots in the selected study field. Our professionals 
 
understand the framework that follows the broad to
pic, the 
 
difficulty, and the backdrop before moving on to a p
articular 
 topic to present the hypothesis.
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