1 / 52

Rod Jackson EPIQ group University of Auckland, NZ www.epiq.co.nz

GATE: ‘EBP with pictures’. a G raphic A pproach to T eaching E BP a G raphic A ppraisal T ool for E BP G raphic A rchitectural T ool for E pidemiology. Rod Jackson EPIQ group University of Auckland, NZ www.epiq.co.nz. 5/9/05 Oxford. ©.

osias
Télécharger la présentation

Rod Jackson EPIQ group University of Auckland, NZ www.epiq.co.nz

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. GATE: ‘EBP with pictures’ a Graphic Approach to Teaching EBP a Graphic Appraisal Tool for EBP Graphic Architectural Tool for Epidemiology Rod Jackson EPIQ group University of Auckland, NZ www.epiq.co.nz 5/9/05 Oxford ©

  2. What is evidence-based practice (EBP)? Policy Evidence ‘ways of knowing” Practitioner Patient

  3. What is evidence-based practice? Policy Evidence ‘ways of knowing” Practitioner Patient

  4. What is evidence-based practice? ‘using more evidence from clinical epidemiology (on diagnosis, prognosis & interventions) to inform decisions’ • more comprehensively (systematic reviews) • more critically (evidence appraisals) • more quantitatively (probabilities)

  5. What is the ‘evidence’ of EBP? ‘clinically relevant evidence, sometimes from basic science, but especially from patient-centred clinical research into the accuracy of diagnostic tests*, the power of prognostic markers*, and the efficacy & safety of interventions*’ Modified from Sackett et al. EBM 2nd Edition 2000 * from clinical epidemiological studies

  6. Epidemiological evidence is the cornerstone of EBP ‘understanding epidemiological study design is the essential skill for teachers of EBP’

  7. The 4 (5) steps of EBP Ask a focussed clinical question Search for appropriate epidemiological evidence to help answer question Appraise (critically) the evidence (validity, impact, precision) Synthesise the evidence with patient, clinical & policy issues; then apply (i.e. answer question) Assess/ evaluate practice (clinical audit). Modified from DS et al

  8. CATs: Critically Appraised Topics: ‘a tool for modeling the steps of EBP’ www.epiq.co.nz

  9. CAT forms: (in Excel) Intervention Diagnosis Prognosis/Risk (coming) Systematic Reviews (coming) download from: www.epiq.co.nz

  10. The GATE Approach: every epidemiological study hangs on the GATE frame • there is only one study design: • RCT - interventions • Cohort studies - prognosis / interv./ aetiology • Cross-sectional studies - diagnosis • Case-control studies - interv./aetiol. GATE: Graphic Appraisal Tool for Epidemiology

  11. GATE Frame: PECOT P • Population • Exposure • Comparison • Outcome • Time E C T O © GATE: Graphic Appraisal Tool for Epidemiology

  12. GATE: epi study design (P) Population P ©

  13. Source Population: 68,561 women screened from 20 outpatients/community screening centres Eligible Population: Post-menopausal, established CHD, < 80 yrs, no MI in last 6 mths, no HRT last 3 months P Participant Population: all eligibles invited (2763)

  14. GATE: epi study design (E&C) Population P Comparison (C) [control] Exposure (E) [or intervention] E C ©

  15. HRT Identical Placebo Comparison (C) [control] Exposure (E) [or intervention] E C

  16. GATE: epi study design (O) Population P Comparison Exposure E C a b yes Outcomes (O) O no c d ©

  17. 1º CHD E C yes Outcomes (O) O no

  18. mean HDL cholesterol (mmol/L) HRT Placebo Outcomes (O) 1.4 1.27

  19. GATE: epi study design (T) Population P Comparison E C Exposure T Time (T) Outcomes O ©

  20. E C T Time (T) O CHD measured over 4.1 years(longitudinal)

  21. E C T Time (T) O HDL cholesterol measured at 1 year(cross-sectional)

  22. GATE: epi study design Population P Comparison E1 C Multiple Exposure categories E2 E3 Multiple Outcome categories ©

  23. GATE: epi study design Population P E Continuous measure of Exposure: e.g. body mass index high…med..low Correlation coefficient low Continuous measure of Outcomes e.g. lipids O medium high ©

  24. Cohort (Follow-up) study: archetypal epidemiological study Population P cohort non-randomised allocation EG CG Exposure Group Comparison Group Real life time T Time ill-health Outcomes O © “Life” is a cohort study: a “natural experiment”

  25. Cohort study (prognosis): Danish Breast Cancer Cooperative Cohort of women diagnosed with breast cancer Population P Non-randomised allocation to prognostic groups No childbirth <2 yrs before diagnosis childbirth <2yrs before diagnosis EG CG T 10 years yesdeath .no O © Kroman et al. BMJ 1997;315:851-5

  26. Cohort study (aetiology): British Doctors Study Cohort of British Doctors established in 1951 Population P Non-randomised allocation (self-reported smoking) EG CG Non-smokers Smokers 50 years T yesLung Cancer .no O © Doll et al. BMJ 2004;328:1519

  27. Cohort study (intervention): Nurses Health Study Cohort of US Nurses Population P Non-randomised allocation (self-reported use) EG CG No HRT HRT 10 years T yesCHD .no O © Stampfer et al. NEJM 1991;325:756-62

  28. Randomised Controlled Trial (RCT): HERS Population P Randomised allocation Exposure (intervention): HRT Comparison (control): Placebo EG CG T Time Outcomes: CHD O © Hulley et al. JAMA1998;280:605-13

  29. Case series Population P Exposure Grp EG C No one allocated to Comparison Group T Time Outcomes O ©

  30. Before-After Study (& cross-over study) Population P CG Comparison Grp Allocation: randomised or non-randomised EG Exposure Grp T Time Outcomes O ©

  31.  LTPA  angina  LTPA  angina Cross-sectional (prevalence) study/survey: PECO Population P Real life time O EG CG Time ? O EG CG © E/C assignment & Outcomes assessed in cohort at same Time

  32. Diagnostic Test Accuracy Study (cross-sectional) Population P Allocation by measurement EG:Gold Standard +ve CG:Gold Standard -ve EG CG Time GS+ GS- +Test Outcomes .- b a O d c ©

  33. Diagnostic Test Study Application (cross-sectional) Population P Allocation by measurement EG:Test +ve CG:Test -ve EG CG Time T+ T- +ve predictive value. b a O -ve predictive value. d c ©

  34. GATE: the NUMBERS Population P= Exposure Group EG= CG= Comparison Group Time T= a= b= Outcomes c= d= ©

  35. GATE: the numbers = HERS P= 2763 Population EG= 1380 CG= 1383 Exposure Group Comparison Group Time a= 172 b= 176 T= 4.1 yrs Outcomes ©

  36. Occurrence = outcome / population P= Population Denominators = EG x T and CG x T sub-populations EG= CG= T b= + a= Numerators = a or c and b or d outcomes - c= d= © Epidemiology = numerator / denominator (E=N/D)

  37. GATE: occurrence = numerator / denominator P= T= EG= CG= Exp. Group Occurrence EGO = a / EG x T Comp. Group Occurrence CGO = b / CG x T a= b= c= d= EGO = c / EG x T EGO = d / EG x T ©

  38. GATE: occurrence HERS P= 2763 T= 4.1 yrs EG= 1380 CG= 1383 Exp. Group Occurrence EGO = A / EGxT= 172/1380 x 4.1= 30.40/1000/yr A= 172 B= 176 Comp. Group Occurrence CGO = B / CGxT= 176/1383 x 4.1= 31.04/1000/yr

  39. Occurrence EGO = Exposure Group Occurrence (A/[EGxT]) CGO = Comparison Group Occurrence (B/[CGxT] = 30.40 / 1000 persons / year = 30.40 / 1000 persons / year

  40. Effects: comparing occurrences Relative Effect/Risk (RR) = EGO CGO e.g. relative risk, risk ratio, prevalence ratio, incidence ratio Absolute Effect/Risk Difference (RD) = EGO - CGO e.g. risk difference, absolute risk Number Needed to Treat (NNT) to prevent/cause 1 event = 1/RD

  41. Using GATE to frame all the steps of EBP www.epiq.co.nz

  42. STEP 1: Ask focussed 5-part questions: 1. Participants (patient/population group) 2. Exposure (intervention if about therapy) 3. Comparison (there is always an alternative!) 4. Outcome 5. Timeframe

  43. STEP 2: Search for best evidence using 3/4-part search terms: 1. Participants (patient/population group) 2. Exposure (intervention if about therapy) 3. Comparison (e.g placebo) 4. Outcome

  44. Step 3a: appraise the evidence - hang the study & numbers on the GATE frame: PECOT Population P Exposure Comparison E C T Outcome O Time ©

  45. Step 3b:appraise the evidence: ‘did the right people get in the right places? RAMM Representative of who? P Allocated appropriately? Measured well?-blinded or objective-complete E C T Measured well?-blinded or objective-complete O ©

  46. R A M M

  47. EBCP Step 4: applying the evidence - the X-factor ©

  48. X-factor: making evidence-based decisions Epidemiologic evidence Patient preferences Policy issues clinical considerations ‘clinical expertise: other ways of knowing’ X-factor: integrating everything

  49. Step 4

More Related