Literature review
Assoc. Prof. Dr Nor Azwany Yaacob
MCommMed (Epidemiology & Biostatistics)
Department of Community Medicine
Intensive Course on Basic Statistics & Research MethodologyFor Mmed, MSc & PhD
What is a Literature?
the works you consulted
in order to understand
and investigate your
research problem.
an account of what has
been published on a
topic by accredited
scholars and researchers.
Scholars / Researchers
Published articles
What is Literature review?
LR
Refines research problem
•Theories, concepts
•Main questions & problems
been addressed
•Issues & debates /
contradictories
Establish
conceptual
framework
Identify best workable method
• What others use?
• What are the limitations?
• Differences & similarities
Study Justification
Identify best way to analyse data
• Outcome variable
• Predictors
• Confounders
Identify best way to discuss
findings
• Differences & similarities
• Explain your findings
Research Methodology
OBJECTIVES
WHAT IS LITERATURE REVIEW..
Provide research context from existing work
It is not supposed to be just a summary of other people's work!
Purpose:
To convey established knowledge and ideas on a topic - strengths & weaknesses
Must be defined by a guiding concept
Problem statement
Research objectives
WHY WRITE A REVIEW OF THE LITERATURE?
Critical look at the existing relevant research
Summarize relevant research - concise description of an article
evaluate the research – correct methodology & result
show the relationships between different research
show how it relates to your research
What other methodologies have been used?
How are they similar?
How are they different?
need to select what parts of the research to discuss (e.g. the methodology)
It is not supposed to be just a summary of other people's work!
Literature review demonstrate skills in :
Information seeking
ability to search and identify relevant literatures efficiently
Critical appraisal ability to apply principles of research methodology in
identifying unbiased and valid studies.
Idea Organization
relate the problem statement and established information to identify gap of knowledge
identify areas of controversy in the literature
formulate questions that need further research
Justify the need of research
Specify research objective
• What do we already know in the immediate area concerned?
• What are the characteristics of the key concepts or the main
factors or variables?
• What are the relationships between these key concepts, factors
or variables?
• What are the existing theories?
• Where are the inconsistencies or other shortcomings in our
knowledge and understanding?
• What views need to be (further) tested?
• What evidence is lacking, inconclusive, contradictory or too
limited?
• Why study (further) the research problem?
• What contribution can the present study be expected to make?
• What research designs or methods seem unsatisfactory?
Questions your literature review should answer:
Purpose
LR should be able to illustrate
The depth of understanding the topic
Study focus
Conceptual framework of the study
Decision made to proceed with the study
Methodology was well planned
Contribution of the study to the medical knowledge
Added value
GETTING STARTED
Topic and key terms
P: Patient / Target
I: Intervention
C: Comparison
O: Outcome
W: What
W: Why
W: Where
W: Who
H: How
TO START ON..ASK YOURSELF What is
specific thesis, problem, or research question
type of literature review issues of theory?
methodology?
policy?
quantitative research (e.g. on the effectiveness of a new procedure)?
qualitative research (e.g. studies )?
scope types of publications (e.g. journals, books, government
documents, popular media)?
discipline e.g. nursing psychology, sociology, medicine
Traps..
Trying to read everything!
Only the most relevant and significant work.
Reading but not writing!
Write while review
Don't think of what you first write as being the final or near-final version.
Allow yourself to write as many drafts as you need, changing your ideas and information as you learn more about the context of your research problem.
Example ~ scope of review
Title : The effect of Honey on glycemic control in
type 2 diabetes patients
Focus : Type 2 DM
Keywords:
Honey
Glycemic control
P: Type 2 DM
I: Honey
C: Placebo
Honey like sugar free
O: Glycemic control
based on HbA1c
Scope of review Burden of disease for type 2 DM
Justify the importance of the study
High morbidity & mortality
Poor glycemic control increase the risk of complications
Article that show Increasing prevalence of diabetes Mentioning the demographic characteristics Race – honey more popular among Malays
Association between glycemic control & complications Study on the cost analysis of diabetes & its complications
P
Scope of review Study criteria
Diabetics on OHA
Exclude ?
diabetics on insulin
Diabetics with complications – renal failure….
Article describing•Management of DM ~ WHO guide•Any Contraindication for honey? •Justify why exclude ~ different response between OHA / Ins
Review study focus
•What in the honey that makes you think its useful to be use in T2DM •Animal study on antioxidant property•Physiological effect of honey
I Diabetes and honey
Review study focus
•What can be use as honey placebo•Ethical issue – use sugar-based material in DM
C Placebo for honey
Review study focus
O GLYCEMIC CONTROL
Lab-based biochem article on•What, when, advantage of using HbA1c in
monitoring glycemic control•Comparing other parameters such as FBS
Justify the study
Why is important to do this study?
Studies that showed•Importance of control glycemic in T2DM•Previous studies suggest antioxidant effect that may beuseful – biologically sound
•Can be alternative for patients who had poor compliance for drug
How your study findings can be used?
What if really no study done before?
No study done in diabetics
Search
Study in healthy subject or diseases of metabolic type
Highlight the effect of honey in other disease treatment
There is always studies related to the issues…
No literature to review means NOT ENOUGH SEARCH…
Searching literature
Tips..
Search relevant systematic reviews ~ use the
references & its link
Search using key words ~ use “related link”
Use boolean operators
Keep records of your search by the keywords
Which article is good?
Guideline article
Known author of the field
Relevant organization committee
WHO, NHLBI..
CRITICAL APPRAISAL
CRITICAL APPRAISALINTRODUCTION
Relevant
Added value of the study
METHODOLOGY Study design: Level of evidence
Clear data collection method
Valid & reliable research tools
Adequate Sample size
Appropriate Sampling method
Well defined Subject selection criteria
Appropriate Statistical analyses
RESULT Well presented – understandable
Significance level & confidence interval
DISCUSSIONRelevant to study
Applicable to your study population
Critical appraisal
Title & abstract
Relevant to the study
Methodology
Study design
Hierarchy of evidence
RCT is better than cross sectional study
Study conduct
Well spell out, understandable
Use standard parameters
Validated, reliable research tool
Critical appraisal
Study sample
Adequate sample size
Sampling method done
Study criteria appropriate
Comparable & appropriate control group
Minimal loss drop out
Applicable to your study sample
Research tool
Validated
Reliable
Standard
Critical appraisal
Result
Appropriate statistical analysis
Bias & confounders adjusted
Not wide 95% Confidence interval
Discussion
Relevant to the study result
Related & can be applied to your study
How to quote..
READ THE WHOLE ARTICLE FIRST !!!
Appraised the study
Understand the discussion
NOT JUST QUOTE FROM ABSTRACT…….
Copy paste the sentences???
Quote the findings and comment the study
PLAGIARISM
Deliberate Plagiarism
Rewriting from books or
articles
Copying & pasting from web
pages & online sources to
create a PATCHWORK
writing
Buying, downloading or
borrowing a paper
Accidental Plagiarism
Not knowing when & how to
cite
Not knowing how to
paraphrase or summarize
Not knowing what “common
knowledge is”
Recycling old paper
How to quote
Sidek et al reported half of the 30 diabetics patients
practice honey as complementary to hospital treatment. 20%
reported faster wound healing
Sidek et al reported half of the unselectedinterviewed Malay patients in Singapore tookHoney as complementary medicine. The study include all type 2 diabetics patients who are on diet control, OHA or Insulin therapy. They measure the outcome ….
Example
Holden (1973) focused attention of the control of behavior by the removal or destruction of portions of the human brain, a procedure usually called psychosurgey. Psychosurgery has been recommended for curing or ameliorating various psychiatric problems, including depression (Knight, 1969) and criminal behavior (Koskoff and Goldhurst, 1968) and has also been used in the treatment of anorexia nervosa (Valenstein, 1973). Recent studies on the functional role of the frontal lobes (Pribram et al, 1964; Thorne 1972) have shown that ……..
Top Related