SYSTEMATIC REVIEWS METAANALYSIS PERTEMUAN 8 ABDUL CHALIK MEIDIAN

SYSTEMATIC REVIEWS & META-ANALYSIS PERTEMUAN 8 ABDUL CHALIK MEIDIAN PRODI S 1 FISIOTERAPI 1

KEMAMPUAN AKHIR YANG DIHARAPKAN • Mahasiswa mampu memahami systematic review dan meta analisis 2

‘Hierarchy of evidence’ 3

Evidence Pyramid for Treatment Effectiveness Questions Goal: Use best available evidence 4

Types of Reviews • Systematic Review: literature review focused on a single question which tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question • Meta-analysis: a statistical technique often used in systematic reviews that enables the results from a number of studies to be combined into a common metric to determine the average effect of a given technique. Comparisons can then be made about the relative effectiveness of various techniques • Integrative Review: literature review that attempts to combine experimental and nonexperimental studies, or from experimental and theoretical work. Can be used to review theories, evidence, or to analyze methodological issues • Qualitative Review: methods for combining qualitative research studies. Techniques include meta-synthesis, formal grounded theory, and meta-ethnography 5

Types of reviews Reviews (narrative/literature/ traditional) Systematic reviews Meta-analysis 6

Review Stages • Problem formulation • Literature search • Data evaluation/extraction • Data analysis • Presentation 7

Narrative reviews • Usually written by experts in the field • Use informal and subjective methods to collect and interpret information • Usually narrative summaries of the evidence 8

Key elements of a systematic review Structured, systematic process involving several steps : 1. 2. 3. 4. 5. 6. 7. Formulate the question Plan the review Comprehensive search Unbiased selection and abstraction process Critical appraisal of data Synthesis of data (may include meta-analysis) Interpretation of results All steps described explicitly in the review 9

Systematic vs. Narrative reviews • Scientific approach to a review article • Criteria determined at outset • Comprehensive search for relevant articles • Explicit methods of appraisal and synthesis • Meta-analysis may be used to combine data • Depend on authors’ inclination (bias) • Author gets to pick any criteria • Search any databases • Methods not usually specified • Vote count or narrative summary • Can’t replicate review 10

Advantages of systematic reviews • Reduce bias • Replicability • Resolve controversy between conflicting studies • Identify gaps in current research • Provide reliable basis for decision making 11

What is a Systematic Review? • “A review that is conducted according to clearly stated, scientific research methods, and is designed to minimize biases and errors inherent to traditional, narrative reviews. ” • “collates all empirical evidence that fits prespecified eligibility criteria in order to answer a specific research question ” 12

What is a Systematic Review? • Clearly stated objectives with pre-defined eligibility criteria for studies • Explicit, reproducible methodology • A systematic search that attempts to identify all studies • Assessment of the validity of the findings of the included studies (e. G. Risk of bias) • Systematic presentation, and synthesis, of the characteristics and findings of the included studies 13

What is the significance of Systematic Reviews? • The large amount of medical literature requires clinicians and researchers alike to rely on systematic reviews in order to make an informed decision. • Systematic Reviews minimize bias. “A systematic review is a more scientific method of summarizing literature because specific protocols are used to determine which studies will be included in the review. ” Kevin C. Chung, MD, Patricia B. Burns, MPH, H. Myra Kim, Sc. D, (2006) 14

Why are Systematic Reviews Necessary? • “The volume of published material makes it impractical for an individual clinician to remain up to date on a variety of common conditions. This is further complicated when individual studies report conflicting conclusions, a problem that is prevalent when small patient samples and retrospective designs are used. ” Margaliot, Zvi, Kevin C. Chung. “ (2007) 15

Why are reviews needed? • • • Massive numbers of publications Both print, and electronic media Diverse languages Different countries Primary studies can appear contradictory Psychology and social sciences predated medical systematic reviews (1930 s) 16

Why are systematic reviews needed? Literature/narrative/critical review: • Often not replicable/updated • May be biased by prior beliefs • May be commissioned due to published opinion • Often miss small but important effects • Different reviewers reached different conclusions • Affected by subspecialty of reviewer • Little attempt to discuss heterogeneity 17

Why are systematic reviews needed? Benefits of therapy not brought into clinical practice • e. g. Clot-busters/beta blockers for heart attacks • SR would have identified benefit in mid-1970 s • Not in clinical practice till 1990 s Inadequate summaries of current knowledge • Omitted mention of effective treatment, or suggested only as part of trials 18

Why are systematic reviews needed? • • As part of student dissertation/PG thesis To secure grant funding for research To propose future research agenda To establish clinical or cost-effectiveness To establish feasibility of an intervention To allow information to be assimilated quickly and easily To reduce delay of research to clinical practice Note this is as substantial a piece of work as original research 19

Problems with systematic reviews • Vary in quality • Require updating (often by time of publication) • May not include all studies – Non-English – Grey literature – Early literature • Quality assessment can still be subjective 20

Key Characteristics of Systematic Reviews 1. Clearly stated title and objectives 2. Comprehensive strategy to search for relevant studies (unpublished and published) 3. Explicit and justified criteria for the inclusion or exclusion of any study 4. Clear presentation of characteristics of each study included an analysis of methodological quality 5. Comprehensive list of all studies excluded and justification for exclusion Linda N. Meurer, MD, MPH Department of Family and Community Medicine. “Systematic Synthesis of the Literature: Introduction to Meta-analysis”. Power Point Presentation. 21

Characteristics of Systematic Reviews (cont. ) • Clear analysis of the results of the eligible studies – statistical synthesis of data (meta-analysis) if appropriate and possible; – or qualitative synthesis • Structured report of the review clearly stating the aims, describing the methods and materials and reporting the results Linda N. Meurer, MD, MPH Department of Family and Community Medicine. “Systematic Synthesis of the Literature: Introduction to Meta-analysis”. Power Point Presentation. 22

Referensi 1. 2. 3. 4. 5. Margaliot, Zvi, Kevin C. Chung. 2007. “Systematic Reviews: A Primer for Plastic Surgery Research. ” Kevin C. Chung, MD, Patricia B. Burns, MPH, H. Myra Kim, Sc. D. 2006. “Clinical Perspective: A Practical Guide to Meta-Analysis. ” Ford AC, Talley NJ, Speigel BMR, et al. (2008) Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis. Klassen et al. 1998. Guides for Reading and Interpreting Systematic Reviews. Arch Pediatr Adolesc Med ; 152: 700 -704. Thomas, et al. , 2004. Integrating qualitative research with trials in systematic reviews. BMJ, 328, 1010 -1012. 23