Dr. Engle has received an unrestricted educational grant for the MD Anderson Pain Medicine Fellowship.

Transcription

1 Mitchell Engle, MD, PhD Dr. Mitchell Engle earned his medical degree and a Ph.D. in Pharmacology from the University Of Iowa Carver College Of Medicine. His Ph.D. research examined the role of the spinal cord and primary afferent neuron GABA B receptors in the initiation and maintenance of neuropathic pain. He completed a residency in Anesthesiology at the University of Alabama-Birmingham followed by a fellowship in Pain Medicine at MD Anderson Cancer Center. He is board certified by the American Board of Anesthesiology in Anesthesiology and Pain Medicine. He is currently an assistant professor in the Department of Pain Medicine at MD Anderson Cancer Center. In addition, he serves as the pain medicine fellowship program director. His current research interests include persistent post-surgical pain, cancer related pain and teaching evidence-based medicine. Dr. Engle has received an unrestricted educational grant for the MD Anderson Pain Medicine Fellowship.

2 Evidence Based Pain Medicine: Improving Clinical Outcomes Through the Judicious Utilization of Data from Clinical Studies. Mitchell Engle, MD, PhD Assistant Professor of Pain Medicine MD Anderson Cancer Center 29 October 2016

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4 Our Roadmap What is EBM? The Cycle of Evidence Study Designs Criticisms of EBM Teaching and Learning EBM

5 Archibald Cochrane Many of the treatments, interventions, tests, and procedures used in medicine have no evidence to demonstrate their effectiveness and may in fact be doing more harm than good Evidence, Evidence, Evidence

6 What is EBM or EBP? Evidence Based Practice (EBP) is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of the individual patient. It means integrating individual expertise with the best available external clinical evidence from systematic research and patient preferences/values. -David Sackett M.D.

7 What is EBM or EBP?

8 Best Research Evidence Trickier than we think Requires Understanding the problem Asking the right question Finding the right information Correct interpretation Applying it to the patient

9 What Happens If I Don t Understand This Evidence Thing? Also Known As Medicine by Media

10 Eating Margarine Leads to Divorce!

11 But Doctors Don t Do That Do They???

12 What is Best Research Evidence? It Starts and Ends With Patients

13 Cycle of Evidence Based Medicine Assess Apply Ask Appraise Acquire

14 Cycle of Evidence Based Medicine Assess Apply Ask Appraise Acquire

15 Cycle of Evidence Based Medicine Assess Question type - Intervention - Diagnosis - Prognosis - Etiology/Harm Apply Ask Appraise Acquire

16 Cycle of Evidence Based Medicine Assess Apply Ask Appraise Acquire

17 Constructing Good Clinical Questions P.I.C.O. Method P = Patient or Problem problem, disease, sex, race, age I = Intervention intervention, exposure, drug, surgery, tests. C = Comparison compared to what?, drug, placebo O = Outcome pain, hospital admission, death

18 P.I.C.O. Example The Question: In a patient with post-laminectomy pain syndrome, are pain outcomes better with repeat surgery or spinal cord stimulation? Patient: Post-laminectomy pain; failed back surgery syndrome Intervention: Spinal Cord Stimulation; dorsal column stimulation Comparison: Surgery; fusion Outcome: pain; Oswestry; disability

19 Cycle of Evidence Based Medicine Assess Apply Ask Appraise Acquire

20 Where Do I Look? Pubmed Cochrane Database of Systematic Reviews Dynamed POC reference tool Uptodate.com

21 Cycle of Evidence Based Medicine Assess Apply Ask Appraise Acquire

22 Quality Levels of evidence

23 Quality Are You Having an Experience or Are You Performing an Experiment?

24 Quality Case-Control Studies

25 Case Control Exposure Outcome No Exposure Exposure No Exposure No Outcome

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27 MBB IA Facets 50% pain after RFA MBB IA Facets < 50% pain after RFA

28 Quality Levels of evidence

29 Cohort Study Outcome Exposure No Outcome Outcome No Exposure No Outcome

30 Nurses Health Study

31 IT Opioid Infusions Deceased Alive Deceased SCS Alive

32 So why not just do cohort studies? -Cheap -Easy -Simple to administer CONFOUNDERS!!!

33 Confounding Factors Other patient features/causal factors, apart from the one being measured, that can affect the outcome of the study.

34 How do you account for confounders? RANDOMIZATION! Hence, the Randomized Controlled Trial -AKA randomized cohort study

35 RCT Outcome Exposure No Outcome Randomization Outcome No Exposure No Outcome

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37 How Important Is Randomization?

38 Types of Randomization Quasi-randomization e.g date of birth, alternating Simple randomisation e.g repeated coin tossing, random sequence Stratified/blocked randomisation Minimized randomisation Cluster randomisation

39 Fundamentals of a Good Trial Concealment Primary End Point Blinding Equal Treatment Intention to Treat Analysis Follow-up Reporting

40 Ensuring Allocation Concealment Concealment: ensuring that enrolling physicians cannot guess the randomized assignment prior to enrollment and randomization. BEST most valid technique Central computer randomization DOUBTFUL Envelopes, etc

41 Endpoints Primary Endpoints 1 outcome (what is measured) 1 time point (when it is measured) Secondary Endpoints Beware of Fishing Expeditions

42 Blinding

43 Blinding Bias: The degree to which the result is skewed away from the truth Were the outcomes measured blindly by researchers and participants? Double blinding (low risk of bias) Subjects and investigators (outcome assessors) both unaware of allocation Single blinded (moderate risk of bias) Either subjects OR investigators (outcome assessors) unaware of allocation No blinding (high risk of bias) Subjects and investigators aware of allocation Other Blinding: Interventionalists, Treating physicians, Statisticians

44 Intention To Treat Once a participant is randomised into a group, they should be analysed in that same group

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47 Follow-Up How many people were lost to follow-up? Losses should be equal between groups >20% should raise suspicion Why were they lost to follow-up? Poor record keeping Side effect Lack of effectiveness Death

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49 What is a Meta-Analysis A study that combines the results from multiple studies in order to: Increase power Improve estimates of effect size Resolve uncertainty when reports disagree Prevent large expensive trials

50 Understanding the Forest Plot

51 Arcidiacono et al, CDSR 2011, Issue 3 CPN Forest Plot

52 Effect Calculations Experimental Effect Rate (EER): The proportion of patients in the experimental treatment group who are observed to experience the outcome of interest. Control Event Rate (CER): The proportion of patients in the control group who are observed to experience the outcome of interest. Absolute Risk Reduction (ARR) = CER-EER Relative Risk Reduction (RRR) = (CER-EER)/CER Number needed to treat (NNT) = 1/ARR The number of patients who need to be treated with the specified intervention to prevent one bad outcome or produce one good outcome over the period of time specified in the study.

53 Effect Calculations

54 Responder Analysis Henschke et al. Eur Spine J 2013 Moore et al Ann Rhem Dis 2010

55 Cycle of Evidence Based Medicine Assess Apply Ask Appraise Acquire

56 Questions to Ask Yourself Would my patient have been eligible for enrollment in this study? Would my patient have enrolled in this study? Does my patient have a unique comorbitidy or characteristic that wasn t accounted for? Does this test/treatment make sense in my patient s current clinical situation?

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58 Where Will My Patient End Up?

59 The N = 1 Trial

60 Classical Criticisms of EBM Devalues basic science knowledge Devalues tacit knowledge developed with clinical experience Difficulty extrapolating population results to a single patient Greenhalgh et al, BMJ (2014) 348:G3725

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62 Recent Criticisms of EBM Distortion of evidence by Vested Interests Pharma Device manufacturers Insurers Too much evidence Marginal gains due to overpowered studies Overemphasis on algorithmic rules Poor fit for multimorbidity Greenhalgh et al, BMJ (2014) 348:G3725

63 Ben Goldacre Watch his TED Talks!

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66 How Now Shall We Practice?

67 Why We Teach EBM at MDA EBM skills are critical for the effective practice of pain medicine Understanding the how of research is necessary to maintain competency as the specialty evolves During a 1 year fellowship, very few people gain knowledge of the primary literature Even though this is the best/only time to teach this

68 Goals of EBM at MDA Develop fundamental EBM skills Expose fellows to landmark papers in the field of pain medicine Develop consultant level knowledge in our fellows

69 Structure of EBM Teaching at MDA Daily clinical questioning Weekly EBM appraisals Landmark Papers Structured analysis format Analysis and application only Monthly EBM journal club Entire circle of EBM CASP criteria

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71 Weekly EBM Topics at MDA Epidural steroid injections Diagnostic testing RFTC for neck and LBP Opioids for noncancer pain Opioids for cancer pain Opioid guidelines Celiac plexus neurolysis Spinal cord stimulation Intrathecal pumps Vertebral augmentation Anticoagulation guidelines Spine surgery for disc herniation CBP for pain Comprehensive pain programs CAM

72 Summary EBM starts and ends with patients Critical evaluation of clinical studies is a learnable skill Understanding the mechanics of a study helps to understand potential bias EBM practices can be incorporated into a busy work flow to improve clinical outcomes EBM education teaches discrete knowledge and develops consultant level level skills in the practice of pain medicine

73 Thank You