1 / 102

EVIDENCE BASED LABORATORY MEDICINE

EVIDENCE BASED LABORATORY MEDICINE. By Dr.R.Ramesh MD Professor Of Biochemistry, Manakula Vinayagar Medical college, Pondicherry.

genero
Download Presentation

EVIDENCE BASED LABORATORY MEDICINE

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EVIDENCE BASED LABORATORY MEDICINE

  2. By Dr.R.Ramesh MD Professor Of Biochemistry, Manakula Vinayagar Medical college, Pondicherry

  3. "THE THREE MAIN TASKS OF THE CLINICIAN AREDIAGNOSIS, PROGNOSIS, AND TREATMENT.OF THESE DIAGNOSIS IS BY FAR THE MOST IMPORTANT, FOR UPON IT THE SUCCESS OF THE OTHER TWO DEPENDS."RYLE J.A. The natural history of disease 2nd ed. Oxford University Press, 1948

  4. What I will be sharing with you Today?

  5. 1.What is evidence based laboratory medicine? 2.What are the components of EBLM? 3. How to ask a question? 4. How to acquire information? 5.How to analyze the information? 6.How to apply the information? 7.Critics view of EBLM.

  6. What is Evidence based Medicine ?

  7. EBLM Conscientious explicit and judicious use of current best evidence in Laboratory medicine for making well informed decision

  8. COMPONENTS OF EBLM Best external evidence Individual expertise EBLM Patients values & expectation

  9. Why evidence based Medicine?

  10. Increased innovation New technologies Greater knowledgeNew treatments & Diagnostics Increased workload More patient visits More spendingSalary and other costs Patient expectationMore knowledge from internet Legal aspects

  11. What are the justification for an evidence based medicine? Constant requirement for information Constant addition of new information Limited time availability The poor quality of access to good information

  12. What is particular to laboratory medicine? Limited number and poor quality of studies linking test Results to patients benefits. The poor perception of the value of diagnostic tests. The ever increasing demand for tests. The disconnected approach to resource allocation. Silo budgeting

  13. How to practice ? ASK • Identification of question • Track down the best evidence • Critical assessment of the best evidence. • Implementation of best practice. • Evaluate Acquire Appraise ACT AUDIT

  14. Elements of EBLM

  15. The First Step of EBLM • Convert a clinical situation into a searchable, (and hopefully answerable) question using • PICO • PATIENT • INTERVENTION • COMPARISON • OUTCOME

  16. PICO P “Patient” refers to the person presenting with the problem, or more simply, to the problem itself. Both concepts are important in searching. atient or Problem I ntervention C omparison O utcome

  17. PICO P “Intervention” refers to the action taken in response to the problem. This is often a drug or surgical procedure, but it can take many forms atient or Problem I ntervention C omparison O utcome

  18. PICO P atient or Problem “Comparison” refers to the benchmark against which the intervention is measured. Often it refers to another treatment, no treatment, or a placebo. I ntervention C omparison O utcome

  19. PICO P atient or Problem I ntervention “Outcome” refers to the anticipated result of the intervention. C omparison O utcome

  20. How to apply this for EBLM?

  21. QUESTIONS TO BE ASKED

  22. Types of question

  23. Type I : Regarding diagnostic accuracy of the test 1.Patients presenting to the emergency department With shortness of breath. 2.How well does N terminal pro B type natriuretic peptide 4. Predict heart failure as assessed by 3. The cardiac ejection fraction measured by Echocardiography

  24. Type II : Related to the value of test in improving Patients outcomes. 1. Patient admitted to the hospital for treatment of heart failure. 2. How well does the use of N terminal Pro B type Natriuretic peptide as a guide to therapy. 3. Improve the length of hospital stay and the rate Of subsequent readmission for heart failure ?

  25. How to Acquire evidence ?

  26. In laboratory medicine an alternative to Clinical trail is Diagnostic accuracy studies. The best design for diagnostic accuracy Studies is a prospective cohort study with a Blinded comparison of the performance of Experimental test and that of an appropriate Gold standard test in a spectrum of patients Suspected to having the disease in question.

  27. An important goal of studies of diagnostics test is to Determine whether the new test adds information to that known from patient observation or other investigations

  28. How to start a search ?

  29. How to seek evidence-based information Computer system Clinical Evidence or PIER (UpToDate) ACP Journal Club, InfoPOEMS, Dynamed Cochrane Library, PubMED Clinical Queries, BMJUpdates, guidelines Original Studies OR SUMsearch or TRIP

  30. Choosing Resources Background Foreground Textbooks Unfiltered Database (e.g. MEDLINE) Rare Filtered/ Pre-appraised Evidence Common

  31. Where to search ?

  32. It is best to start the search with looking for External evidence based guidelines that can be Adapted. The search for evidence usually starts in databases Such as the Cochrane Library which contains high quality Systematic reviews or meta analysis.

  33. If a search is not successful in the secondary Literature one can look for primary reports in the Medline. Use Pub Med for the search of Medline. The best single search term for laboratory test Is “ sensitivity “. However the word “diagnostic test”, “Diagnosis” “Diagnostic use” combined with the corresponding Clinical condition ( eg: Chronic renal failure)and Finally the name of the test ( eg: Soluble transferrin Receptor.

  34. Determine the level of evidence of the primary Studies and reviews. The highest level of evidence is a good quality well Conducted systematic review or meta analysis of RCT for testing patient related outcomes. ( PSA for Screening Prostate cancer ) Prospective cohort studies for Diagnostic accuracy studies. ( Total PSA Vs the free PSA / Total PSA in the diagnosis Of prostate cancer )

  35. What and Why do we choose a systemic review?

  36. Systematic Searching Systematic Reviews

  37. Review articles Definitions A broad overview of a topic, similar to a textbook chapter. • Often covers multiple, background aspects of a disease such as natural history, etiology, epidemiology, signs & symptoms, diagnosis, treatment, and prognosis. • The article summarizes the results from many other primary studies. • The studies to summarize are chosen at the discretion of the author.

  38. Systematic Review Definitions Review articles A broad overview of a topic, similar to a textbook chapter. A type of review article that focuses on a focused clinical question Studies are chosen using a standardized protocol to minimize selection bias.

  39. Meta-analysis Definitions Review articles A broad overview of a topic, similar to a textbook chapter. Systematic Review A type of review article that focuses on a focused clinical question A type of systematic review in which the numerical results from individual studies are mathematically combined to give a single, overall estimate of treatment effect.

  40. Definitions Review articles Systematic Review Meta-analysis • A systematic review can be thought of as a research project done on the medical literature itself. • Instead of human beings acting as subjects, the subjects of a systematic review are individual RCTs

  41. Finding Systematic Reviews • Produces high quality systematic reviews • Managed by the Cochrane Collaboration • A not-for-profit international organization and one of the initial developers of systematic reviews • Available through the HSLIC web site.

  42. Finding Systematic Reviews • Pub Med Clinical Queries • They are accessed from the "Clinical Queries" link on the blue side bar of the PubMed home page.

  43. How to critically appraise an Evidence?

  44. Essential Concepts Three concepts are essential to understanding the critical appraisal of systematic reviews. These are: • Publication bias. Publication bias is one of the factors that systematic reviews attempt to avoid by selecting studies in a systematic way. • Heterogeneity. Heterogeneity is a statistical measure of the difference between the results from different studies. The less heterogeneous results are, the easier it becomes to estimate overall effect.

  45. HOW TO DETECT HETEROGENICITY?

  46. Forrest Plots

  47. Effect of probiotics on the risk of antibiotic associated diarrhoea D'Souza, A. L et al. BMJ 2002;324:1361

More Related