Systematic review

Systematic literature review

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

2. 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 About me 2

3. Acknowledgment 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

4. 4 Literature review 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.

5. Narrative review Traditional expert review; usually subjective in nature Systematic review 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 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 Levels of literature review

6. Systematic review – history Astronomers claim to be the first users of this method Explosion of SRs in health sciences in mid 1980s Term “systematic review” was coined by health care researchers SR became a significant tool for “evidence-based medicine” or “evidence-based practice” 6 Growth of SRs in health sciences

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

8. SR vs. narrative review 8

9. Characteristics of an SR 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

10. Steps in an SR 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

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

12. Protocol 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 and analyzed? How will the quality of studies be assessed? 12

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

14. PICO – example 14

15. Sample questions 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 community-based) interventions effective in preventing smoking in young people? 15

16. Inclusion and exclusion criteria – example 16

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

18. Sources of literature Electronic databases General vs. subject Grey literature 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

19. Search strategy – example 19

20. Search strategy – example 20

21. Record keeping log – example 21

22. Study selection 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

23. PRISMA flow diagram 23

24. PRISMA diagram – example 24

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

26. Quality assessment criteria 26

27. Quality assessment results 27

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

29. Data extraction form 29

30. Summary table of evidence 30

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

32. Best of luck for your research endeavors! 32