Systematic Literature Review Dr Khalid Mahmood Professor Department

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Systematic (Literature) Review Dr. Khalid Mahmood Professor Department of Information Management University of the

Systematic (Literature) Review Dr. Khalid Mahmood Professor Department of Information Management University of the Punjab 1

About me l l l Professor of Information Management at University of the Punjab

About me l l l Professor of Information Management at University of the Punjab Post-doctoral research fellow at University of California, Loss Angeles, USA 150+ publications Supervised many doctoral, M. Phil. and master theses Worked for various research journals as editor, reviewer and editorial board member Conducted many trainings on research writing and publishing 2

Acknowledgment l l I have prepared this presentation with the help of many books,

Acknowledgment l l I have prepared this presentation with the help of many books, presentations and Websites. I pay my sincere gratitude to all authors, professors and experts for their efforts and contributions. 3

Literature review l The general term for all attempts to synthesize the results and

Literature review l The general term for all attempts to synthesize the results and conclusions of two or more publications on a given topic. A review may or may not be systematic. 4

Levels of literature review l Narrative review l l Systematic review l l Traditional

Levels of literature review l Narrative review l l Systematic review l l Traditional expert review; usually subjective in nature A review of a clearly formulated question that uses systematic and explicit methods to identify, select and critically appraise relevant research, and to collect and analyze data from the studies that are included in the review Meta-analysis l l l Quantitative evidence Use of statistical methods to combine the results of various independent, similar studies More precise calculation of one estimate of treatment effect than could be achieved by any of the individual, contributing studies 5

526 6538 6 19 99 20 02 20 05 20 08 20 11 20

526 6538 6 19 99 20 02 20 05 20 08 20 11 20 14 3 19 9 0 1 1 1 272 334 371 323 386 429 482 596 639 741 849 948 1079 1289 1594 2063 2335 2596 2778 3239 3930 4850 l 6 l 19 9 l Astronomers claim to be the l Growth of SRs first users of this method in health Explosion of SRs in health sciences in mid 1980 s Term “systematic review” was 9000 8000 7000 coined by health care 6000 researchers 5000 4000 SR became a significant tool 3000 for “evidence-based medicine” 2000 1000 0 or “evidence-based practice” 19 6 l 8113 7096 Systematic review – history 6

SR – another definition A systematic review “attempts l to collate all empirical evidence

SR – another definition A systematic review “attempts l to collate all empirical evidence that fits prespecified eligibility criteria l in order to answer a specific research question. l It uses explicit, systematic methods that are selected with a view to minimizing bias, l thus providing more reliable findings from which conclusions can be drawn and decisions made. ” 7

SR vs. narrative review 8

SR vs. narrative review 8

Characteristics of an SR l l l Clearly stated set of objectives with pre-defined

Characteristics of an SR l l l Clearly stated set of objectives with pre-defined eligibility criteria for studies Explicit, reproducible methodology Systematic search that attempts to identify all studies that would meet the eligibility criteria Assessment of the validity of the findings of the included studies Systematic presentation, and synthesis, of the characteristics and findings of the included studies 9

Steps in an SR l l l Build a review team Develop a protocol

Steps in an SR l l l Build a review team Develop a protocol or plan Formulate review question Define inclusion and exclusion criteria Locate studies Select studies Assess study quality Extract data Analysis/summary and synthesis of relevant studies Present results Interpret results/determining the applicability of results 10

Review team l l Normally a team work Key skills: l Managing research projects

Review team l l Normally a team work Key skills: l Managing research projects l l l Leading, coordinating Expertise in the topic Methodological expertise l Planning, searching, managing information, coding, analyzing, synthesizing, writing 11

Protocol l l l l What is the title? What is the context and

Protocol l l l l What is the title? What is the context and what are the conceptual issues? What is the aim? What is the research question? What is the search strategy? What are the inclusion / exclusion criteria? How will the data be extracted analyzed? How will the quality of studies be assessed? 12

PICO – question components in medicine l P – Population l l I –

PICO – question components in medicine l P – Population l l I – Intervention l l Drug, procedure, etc. C – Comparison l l Patients (Demographic factors, socioeconomic factors, setting, etc. ) Alternative to compare with intervention (placebo or active) O – Outcome l Improvement, effect, measure, etc. 13

PICO – example 14

PICO – example 14

Sample questions l l l In undergraduate medical education, does the use of clicker

Sample questions l l l In undergraduate medical education, does the use of clicker technology in the classroom improve learning outcomes? Are antiseptic washes more effective than non antiseptic washes at preventing nosocomial infections in patients undergoing surgery? Are mass media (or school-based or communitybased) interventions effective in preventing smoking in young people? 15

Inclusion and exclusion criteria – example 16

Inclusion and exclusion criteria – example 16

Searching literature l l l Identifying major concepts Keywords, synonyms, controlled vocabulary Combination of

Searching literature l l l Identifying major concepts Keywords, synonyms, controlled vocabulary Combination of concepts l l l Identifying where to search Search strategy l l Varies in different databases Export citations to a reference management software l l Boolean operators, string, truncation, proximity, etc. End. Note, etc. Documenting your search l Database name, date of searching, number of results 17

Sources of literature l Electronic databases l l Grey literature l l General vs.

Sources of literature l Electronic databases l l Grey literature l l General vs. subject Conference proceedings, theses, reports, Websites Browsing issues of topical journals Backward and forward citations of the most relevant articles Conversation with experts in the field 18

Search strategy – example 19

Search strategy – example 19

Search strategy – example 20

Search strategy – example 20

Record keeping log – example 21

Record keeping log – example 21

Study selection l l l An initial assessment that occurs following the search It

Study selection l l l An initial assessment that occurs following the search It addresses the question “should the paper be retrieved? ” It is essential to use two assessors in both the selection and critical appraisal processes to limit the risk of error Select only those studies that address the review question and that match the inclusion criteria Scan titles and abstracts If uncertain? - Retrieve - scan full text 22

PRISMA flow diagram 23

PRISMA flow diagram 23

PRISMA diagram – example 24

PRISMA diagram – example 24

Study quality assessment l Choose appropriate checklist l l related to study design It

Study quality assessment l Choose appropriate checklist l l related to study design It is better to use more reviewers l Inter-reviewer reliability 25

Quality assessment criteria 26

Quality assessment criteria 26

Quality assessment results 27

Quality assessment results 27

Data extraction l l Think about what data you need to extract from included

Data extraction l l Think about what data you need to extract from included studies to answer the questions Pilot a draft data extraction form 28

Data extraction form 29

Data extraction form 29

Summary table of evidence 30

Summary table of evidence 30

Data synthesis l l Will results be pooled? How will differences between studies be

Data synthesis l l Will results be pooled? How will differences between studies be taken into account? Can subgroups of data be made? How will results be displayed? 31

Best of luck for your research endeavors! 32

Best of luck for your research endeavors! 32