Davis, C.G. (1998) Rear-end impacts: vehicle and occupant response. JMPT, 21(9): 629-39.

1. Bronfort, G., W. Assendelft, et al. (2001). Efficacy of spinal manipulation for chronic headache: A systematic review. JMPT 24(7): 457-466. Davis, C.G. (1998) Rear-end impacts: vehicle and occupant response. JMPT, 21(9): 629-39.

2. Literature Reviews Another Descriptive Design (Along with case reports, surveys, and case series)

3. DESCRIPTIVE DESIGNS

4. The Literature Review • Summarizes all available literature on a topic to produce a single paper • Imperative to carry out in an objective and critical format • Can cover a broad issue or a very focused clinical question • Example I: Cervical manipulation of whiplash patients • Example II: Cervical manipulation of whiplash patients with signs of VBI

5. Literature Review • A great deal of information is brought together and written so the reader can clearly understand the topic • Literature reviews provide a new conclusion to the literature . . . a synthesis • Not just rehashing all the articles involved

6. Purpose • Objectively report current knowledge concerning a certain topic based upon previously published research • Provide a comprehensive overview of the topic • Place information into perspective • Find out what others have to say

7. Reasons to Read LiteratureReviews • Save time when searching for information about patient care • The author of the literature review has already done most of the work • Provide information for decision makers • Researchers use them to develop hypotheses and to identify pitfalls in previous research

8. LiteratureReviews • May offer more conclusive results than a single primary research study • Reviewing all studies on a topic tends to neutralize the extremes • May provide a very high level of evidence • Meta-analyses • However, readers must consider the possibility of author bias

9. Three Classifications • Narrative review • A comprehensive narrative synthesis of previously published information • Qualitative systematic review • A detailed search of the literature based upon a focused question • Employs detailed, rigorous and explicit search methods

10. Three Classifications Cont. • Quantitative systematic review • Evaluates each reviewed paper and statistically combines the results of the studies

11. From JMPT Instructions for Authors • Literature reviews • Critical assessments of current knowledge of a particular subject of interest • With emphasis on better correlation • The pointing up of ambiguities • And the delineation of areas that may constitute hypotheses for further study • Meta-analysis is included

12. Narrative Literature Review • Three types: • Editorials • Are typically written by the journal’s editor or an invited guest • Commentaries • Typically express an opinion (biased) • Overview articles • A narrative review that draws upon the wisdom of the commentator (biased) • AKA unsystematic narrative reviews

13. Why NarrativeLiterature Reviews? • Usually more up to date than textbooks • However, probably published 2+ years after the research was done • Presents a broad perspective on a given topic • Practitioners can obtain up to date clinical protocols • Often specific authors are solicited to write narrative overviews who are experts • Many times they have conducted related research

14. Systematic Methods Required • Methods used in creating the paper should be revealed • Inclusion/exclusion criteria explained • Language, timeframe, specific type of tx. • The list of sources used to locate literature should be complete • Regarding chiropractic – Not just PubMed • Should include MANTIS, CINAHL, ICL, and others

15. Narrative Overviews - Evidence • One of the weakest forms of evidence for making clinical decisions • They deal with broader issues than focused clinical problems • They are potentially more biased • Which is why they are one of the weakest

16. Qualitative Systematic Literature Review • AKA systematic review • Detailed, rigorous and explicit methods are utilized • Methodology is described step-by-step • Noted for having a focused question or purpose • All original (primary) research studies published on the topic are included

17. Systematic Review Searching • Multiple databases should be searched • Also hand searches • Should contact authors of previously published research • Attempt to locate articles that may not have been published • “Failed” studies

18. Systematic Reviewing Process • Papers are reviewed systematically and consistently • Apply the same criteria to each one reviewed • Several independent reviewers are typically involved • Papers are rated using a scoring system • Checklists are typically involved • Then individual studies are integrated

19. Systematic Review - Evidence • More powerful evidence-based source of clinical information than narrative reviews • Better-quality evidence than • Case reports and case series • Even better than poorly conducted RCTs

20. Quantitative Systematic Literature Review • Commonly known as a meta-analysis • A systematic review that not only critically evaluates each paper, but also statistically combines the results of the studies • Are very methodological like qualitative systematic reviews

21. Meta-analyses – Major Benefit • Pooling of data between studies • All of the original patient data from the studies under review are pooled • Creates a larger sample size for statistical testing • Increases “power” of the individual studies • However, it is often difficult to find studies that are similar enough to pool data

22. Meta-analyses - Evidence • Considered a very high form of evidence for making clinical decisions • More generalizable conclusions are possible • More “power” • Tends to even out extreme values through a process of averaging

25. Writing a Narrative Review of the Literature • Select topic that you are very interested in • Need to have momentum to finish • Select topic with a feasible focus • “Headaches” would be impossible – too broad • Better – “chiropractic management of muscle tension headaches” – more focused • Get help from experienced (published) colleagues or faculty • Possibly offer co-authorship in return

26. Step One • Perform a preliminary literature search • This applies for any research endeavor • To see what has already been published on the topic • There may already be a review published about the topic • However, may still be able to get a review published using a different perspective

27. General Guidelines • Use the required writing elements for a narrative review • Be well structured • Synthesize the available evidence • Convey a clear message • Use an objective and scientific approach • Follow the “Uniform Requirements for Manuscripts Submitted to Biomedical Journals” formatting guidelines

28. Guidelines Cont. • The necessary elements of a narrative review are similar to those required of any form of scholarly article • Standard “anatomy” • Title, Structured Abstract, Introduction, Method, Results, Discussion, Acknowledgements, References, Tables, Figures, and Figure captions

29. Title • Clearly describe the topic being reviewed • May include the words “literature review” or “review of the literature” • Example from JMPT • Alcohol and low-back pain: A systematic literature review

30. Structured Abstract • Objective: Author should clearly state the purpose of the paper • Background: A description of what prompted the review or why it was written. Presentation of a context for the review. • Methods: Brief description of the methods used for the review.

31. Structured Abstract Cont. • Discussion: Description of what information the review presents to the reader. • Conclusion: Summary of what the review contributes to the literature. What new conclusion can be drawn as a result of the synthesis of the literature.

32. Key Words • Use medical subheadings (MeSH) when possible • Additional words that may be unique to this topic

33. Introduction • State the research purpose or focus • Convince readers of the need or importance of the study • Hasn’t been reported previously • Inadequately reported • Incorrectly reported • Define any unusual terms that are used

34. Methods • A step-by-step description of how the study was carried out • List databases that were searched • Typically must search at least two applicable databases in order to obtain a reasonable breadth and depth on a topic • Articles harvested from reference sections • Other sources for references • Conference proceedings, communications with authors, books, etc.

35. Describing Information Sources • Name the database that was searched • List search terms • Define an inclusion timeframe • Provide a starting year and an ending year and month • Example • A MEDLINE search was carried out using the terms “neck pain” and “manipulation” from 1966 through March, 2004.

36. Parameters For The Literature Search • Inclusion and exclusion criteria must be established to focus the search • For example, exclude surgery related studies or drug trials • Use “Limits” in PubMed and “Advanced Search” in MANTIS • Choose language, date, discipline, etc. • Search strategy should be described so another reviewer could duplicate results

37. Results • This section presents the outcome of the search process • The number of articles that were retrieved • How many of the articles were excluded from the review • Which of the inclusion criteria they failed to meet

38. Discussion • The synthesis is the most demanding element of a narrative review • All of the information retrieved in the literature search is combined into comprehensive paragraphs • Notes must be kept for each study reviewed including the following information: • The purpose of the study being reviewed

39. Discussion cont. • A synopsis of the content • The research design or methods used in the study • A brief review of the findings

40. Most reviews have a table of articles that were utilized

41. Synthesis • The synthesis is the heart of the narrative review design • Consequently it is important to ensure that a meaningful integration is accomplished • Based on the literature reviewed, the author should offer an interpretation • Also a critical appraisal of the papers reviewed may be in order

42. Appendix A • Check sheets or guides are helpful when critically appraising the articles • Green BN, Johnson CD, Adams A. Writing Narrative Literature Reviews for Peer-reviewed Journals: Secrets of the Trade. J Sports Chiropr Rehabil 2001:15(1) • 1 = Absent, 2 = Present but not complete, 3 = Present and complete

43. Initial Impression • Does the review appear to be relevant to an issue of interest? • Don’t waste your time reading articles that aren’t relevant or interesting There are plenty available that are relevant

44. Abstract • Is the specific purpose of the review stated? • Is context for the overview provided? • Is the type of research design stated? • Are the search methods clearly summarized? • Are the important findings clearly discussed? • Are the major conclusions and recommendations clearly outlined?

45. Introduction • Is the specific purpose of the review clearly stated based upon a brief review of the literature? • Is the need/importance and context of this study established? • Are novel terms defined?

46. Methods • Were the electronic databases used to conduct the literature searches identified (MEDLINE, CINAHL, etc.)? • Were the search years stated? • Were the search terms stated? • Were standard terms used as search terms, including Medical Subject Headings? • Were the guidelines for including and excluding articles in the literature review clearly identified?

47. Results - Discussion • Were the results summarized in a comprehensible manner? • Was the critical appraisal of each study the same and reproducible? • Was the quality of the included articles assessed objectively? • Was the variation in the findings of the studies critically analyzed?

48. Discussion Cont. • Was the meaning of the results addressed? • Do the authors tie in the results of the study with previous research in a meaningful manner? • Were the weak points and untoward events that occurred during the course of the study addressed by the authors?

49. Conclusions • Was a clear summary of pertinent findings provided? • Were the authors’ conclusions supported by the evidence provided? • Were specific directives for new research initiatives proposed? • Specific implications to the practice environment are addressed?

50. References • Are references relevant, current and appropriate in number? • Are all papers reviewed cited in the references?