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© 2006 The Standard Appraisal Questions. © 2006 Evidence-based Chiropractic 2 Anatomy of a scholarly journal article Abstract Introduction Methods Results.

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Presentation on theme: "© 2006 The Standard Appraisal Questions. © 2006 Evidence-based Chiropractic 2 Anatomy of a scholarly journal article Abstract Introduction Methods Results."— Presentation transcript:

1 © 2006 The Standard Appraisal Questions

2 © 2006 Evidence-based Chiropractic 2 Anatomy of a scholarly journal article Abstract Introduction Methods Results Discussion –(conclusion) Designed to answer: –Is it of interest –Why was it done? –How was it done? –What has it found? –What are the implications? What else is of interest? Adapted from Crombie, 1996

3 © 2006 Evidence-based Chiropractic 3 Scholarly articles (cont.) The anatomy of a scholarly article also includes a reference section Subheadings may be included Articles with missing or incomplete sections are considered flawed Case reports, literature reviews, and editorials have a different structure

4 © 2006 Evidence-based Chiropractic 4 Abstract A brief summary of the article that is usually limited to a few paragraphs –Provides a synopsis of the entire article –Not merely an introduction Review abstracts to quickly determine whether the article is worth reading Then read the article! –Don’t totally rely on the abstract

5 © 2006 Evidence-based Chiropractic 5 Abstract (cont.) Structured abstracts are common –Contain subheadings and subsections e.g., Background, Objectives, Methods, Results, and Conclusions –Traditional abstracts are simply paragraphs Structured abstracts are preferred –Considered more informative than traditional Thought to be more useful by authors Liked by readers

6 © 2006 Evidence-based Chiropractic 6 Appraising the abstract The abstract should present the purpose of the study The study’s findings are correctly and adequately described Check for obvious biases

7 © 2006 Evidence-based Chiropractic 7 Introduction Provides a rationale for the study and conveys the article’s purpose A brief review of the literature is provided –Highlights other research on the topic –It should describe the context of the research Should stimulate the reader’s interest –If uninteresting, consider reading another article

8 © 2006 Evidence-based Chiropractic 8 Introduction (cont.) Should conclude with a clear statement of the study’s purpose –A hypothesis to be tested or a question to be answered –If absent, did author’s know what they were looking for? –Represents a flaw if missing

9 © 2006 Evidence-based Chiropractic 9 Appraising the introduction The purpose of the study is provided –It is clear and logical Should include a review of relevant literature –The review consists of appropriate references that adequately cover the topic

10 © 2006 Evidence-based Chiropractic 10 Materials and methods Provides details of how the study was carried out –How subjects were selected and assigned to groups –Description of equipment, drugs and chemicals (if used) –All procedures are thoroughly described –The experimental design that was utilized

11 © 2006 Evidence-based Chiropractic 11 Methods (cont.) Methods should be clear and in enough detail so other researchers could reproduce the study if desired If human participants or animals are involved, should include a statement about how ethical standards were handled How the data will be analyzed –The statistics computer program used

12 © 2006 Evidence-based Chiropractic 12 An essential component of the “Methods” section A published study should disclose the details of how they estimated their required sample size, including… –Expected or clinically important difference between groups that is sought –Acceptable probability of Type I error –Desired power to detect a difference if there is one –The statistics package (computer program) used to calculate needed sample size

13 © 2006 Evidence-based Chiropractic 13 Was the sample size justified? Should be large enough to give an accurate picture of what’s going on Small studies may fail to detect clinically important effects What size of effect did the study have the power to detect? –May be calculated after study completion

14 © 2006 Evidence-based Chiropractic 14 Sample size justified? (cont.) Low power may be justification to repeat an experiment with a larger sample

15 © 2006 Evidence-based Chiropractic 15 Methods (cont.) Are the data accurate? –How were measurements taken? –Questionnaires & measuring instruments should be valid and reliable Which statistical methods were used in the analysis –Were they appropriate?

16 © 2006 Evidence-based Chiropractic 16 Appraising the methods The research design is appropriate for the study’s purpose –It is adequately implemented The population and samples are identified –Look for potential biases Methods of data collection are described in detail

17 © 2006 Evidence-based Chiropractic 17 Presents the findings of the study –Data are summarized –Tables, illustrations, and graphs are common –Presented in a comprehensive and convincing manner Results

18 © 2006 Evidence-based Chiropractic 18 Results (cont.) Make sure all data has been reported –Missing data may be a sign of the author ignoring data that are contradictory to the study’s hypotheses –Text and tables should be reviewed for accuracy Any statements should be supported by the data

19 © 2006 Evidence-based Chiropractic 19 Appraising the results The data are reported in sufficient detail Demographic characteristics are presented Statistical tests are described –Warning sign: large numbers of tests carried out Potential for spurious significance

20 © 2006 Evidence-based Chiropractic 20 Are measurements likely to be valid & reliable? Detailed description of measurement methods should be given –Read critically, asking how errors could be introduced –Were assessments subjective? –Did more than one observer assess? –Did authors discuss potential measurement errors?

21 © 2006 Evidence-based Chiropractic 21 Measurements (cont.) Author should discuss how reliability & validity were assessed It’s not acceptable to use a measure that has not been previously validated

22 © 2006 Evidence-based Chiropractic 22 Were basic data adequately described? Number of subjects and how they were obtained Basic characteristics, mean & range –What typical measurements look like & how they vary –Important for comparability Begin with simple analyses, giving main outcomes in tables or figures

23 © 2006 Evidence-based Chiropractic 23 Do the numbers add up? Subjects lost to follow-up or missing data should be accounted for If data analyzed in subgroups, all should add up to total –Discrepancies should be accounted for –Small (<1%) discrepancies unlikely to have impact on findings

24 © 2006 Evidence-based Chiropractic 24 Histogram

25 © 2006 Evidence-based Chiropractic 25 Bar chart

26 © 2006 Evidence-based Chiropractic 26 Line chart

27 © 2006 Evidence-based Chiropractic 27 Table example Table 1. Descriptive statistics of total visits, comparing “Trauma” with “No Trauma” cases. TraumaNo Trauma Valid N5539 Mean total visits % CI28.97 to to Minimum11 Maximum11757 Standard deviation

28 © 2006 Evidence-based Chiropractic 28 Was the statistical significance assessed? Chance effects may appear quite large, especially when the sample size is small –P-value ≤0.05 provides evidence that the result is likely to be real rather than chance –Some journals prefer confidence intervals rather than p-values CI shows the range within which the true value could lie, with a certain degree of confidence (usually 95%) A broad range is less reliable

29 © 2006 Evidence-based Chiropractic 29 Discussion – What are the implications? Can the findings be generalized to other people, places and times? Subjective – authors are not always impartial Implications: –What is new? –What does it mean for health care? –Is it relevant to my patients?

30 © 2006 Evidence-based Chiropractic 30 Discussion (cont.) Author should make comparisons to other studies and address discrepancies Conclusions: –Should findings induce changes in clinical practice? –Do findings highlight the need for further research?

31 © 2006 Evidence-based Chiropractic 31 Should be complete and accurate –Most from peer-reviewed journals –Citations from books and web page should be infrequent Only relevant citations that were actually utilized and appropriately cited in the article should be included References

32 © 2006 Evidence-based Chiropractic 32 Appraising the references References are –Appropriate –From high-quality evidence sources –Adequate amount to support statements made in the article Findings of the referenced studies are reliably represented

33 © 2006 Evidence-based Chiropractic 33 What do the main findings mean? Is the effect size clinically significant? –Why or why not? Internal consistency may be demonstrated: –Similar results by age or sex –Dose response –Supports findings as not chance aberration

34 © 2006 Evidence-based Chiropractic 34 What do the main findings mean? Reader should consider whether the authors’ interpretations make sense –Biologic plausibility –Timing of events

35 © 2006 Evidence-based Chiropractic 35 How are null findings interpreted? Was there lack of effect?... OR… Was the study too small to have a reasonable chance of detecting anything? –Wide confidence interval indicates this possibility Lack of evidence of an association is not the same as evidence of no association

36 © 2006 Evidence-based Chiropractic 36 Did untoward events occur during the study? Many problems should have been dealt with in feasibility & pilot studies –Difficulty following research design –Loss of subjects to follow-up –Difficult to make measurements on some individuals

37 © 2006 Evidence-based Chiropractic 37 Untoward events (cont.) Missing data may allow bias to influence the results Midstream changes in design is worrisome –Outcome measures, intervention, inclusion/exclusion criteria, etc. –Data may not be comparable from beginning of the study to after design change

38 © 2006 Evidence-based Chiropractic 38 Are important effects overlooked? Reader should look at the results for unexplored findings, patterns, etc. Researchers, understandably, may draw attention to findings that fit their preconceptions Do they comment on results which do not fit their views or try to gloss over them?

39 © 2006 Evidence-based Chiropractic 39 How do the results compare with previous reports? A single study seldom provides convincing evidence New findings accepted only with substantial “body” of research Confidence diminishes if other studies fail to confirm previous results Findings should be fitted into a balanced overview of all reported studies

40 © 2006 Evidence-based Chiropractic 40 What implications does the study have for your practice? Should this information lead to changes in the management of one’s own patients? –Risk subjecting patients to useless therapy –Risk denying patients access to effective ones –Risk causing anxiety by advising them to avoid harmful behavior

41 © 2006 Evidence-based Chiropractic 41 Implications for your practice (cont.) How big was the effect, and is it clinically important? Were patients & circumstances similar to your practice? –Hospital patients –Age, gender

42 © 2006 Evidence-based Chiropractic 42 Overall Questions to Ask Is the study design appropriate to address the research question? In the Discussion section, are the findings... –consistent with the research question of the study? –consistent with the results presented? –presented in the context of current evidence?

43 © 2006 Evidence-based Chiropractic 43 Use checklists Invaluable tools as you review journal articles, which are often very intimidating to read Contain many of the questions covered in this lecture Specific for the various types of research methodology involved, from case studies to RCTs

44 © 2006 Evidence-based Chiropractic 44 Read the article and evaluate the information There are three basic questions that need to be answered for every type of study: –Are the results of the study valid? –What are the results? –Will the results help in caring for my patient? The issue of validity refers to the “truthfulness” of the information

45 © 2006 Evidence-based Chiropractic 45 Validity of a study? Was the assignment of patients to treatment randomized? Were all the patients who entered the trial properly accounted for at its conclusion? Were patients, their clinicians, and study personnel “blind” to treatment? Aside from the experimental intervention, were the groups treated equally?

46 © 2006 Evidence-based Chiropractic 46 Evaluating health websites Many health-related websites contain false or misleading information Health information from commercial websites may be biased toward a product or service Could negatively affect a patient's health because of incorrect decision-making

47 © 2006 Evidence-based Chiropractic 47 Evaluating health websites (cont.) Be cautious of websites that are overly optimistic or pessimistic on a given topic –Only call attention to one side of an argument and disregard conflicting research findings Indications of an unreliable website –Presents anecdotal information –Makes sweeping generalizations –Half-truths –Points to rare and extreme practices

48 © 2006 Evidence-based Chiropractic 48 University of Maryland’s Center for Integrative Medicine Standards for evaluation of websites 1.Authorship The author’s affiliations and qualifications of should be listed 2.Attribution: References and sources of information should be provided Also pertinent copyright information

49 © 2006 Evidence-based Chiropractic 49 University of Maryland’s criteria (cont.) 3.Disclosure Ownership and sponsorship should be fully disclosed and prominently displayed. 4.Currency Dates that the website’s content was posted or updated should be provided

50 © 2006 Evidence-based Chiropractic 50 Health on the Net Foundation (HON) HON Code of Conduct for health websites 1.Authority –Medical or health advice will only be given by medically trained and qualified professionals unless clearly stated that it is from a non-medically qualified source 2.Complementarity –Information provided is designed to support, not replace, the relationship between a patient and his or her physician 3.Confidentiality –Confidentiality of visitors data is respected by the website

51 © 2006 Evidence-based Chiropractic 51 HON Code of Conduct (cont.) 4.Attribution –Information will be supported by clear references to source data and, where possible, have specific HTML links to that data –The date when a clinical page was last modified will be clearly displayed 5.Justifiability –Any claims relating to the benefits of a treatment, product or service will be supported by appropriate, balanced evidence 6.Transparency of authorship –Website designers will provide information in the clearest possible manner and provide contact addresses and the Webmaster’s address

52 © 2006 Evidence-based Chiropractic 52 HON Code of Conduct (cont.) 7.Transparency of sponsorship –The website’s support will be clearly identified, including the identities of organizations that have contributed funding, services or material for the site 8.Honesty in advertising & editorial policy –If advertising is a source of funding it will be clearly stated –The advertising policy will be described on the site –Advertising will be presented in a manner that makes it easy to differentiate between it and the original material created by the organization operating the site Websites can be accredited by HON if they qualify


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