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

Introduction &

Literature reviewSeparate chapter?

Combined as one chapter of introduction?

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 ……..