8/18/10. Disclosure. Objectives. A Pervasive Concern. Evidence Based Medicine, Family Physicians, and Knowledge Translation (KATIE)

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1 Evidence Based Medicine, Family Physicians, and Knowledge Translation (KATIE) David Gardner PharmD, MSc Michael Allen MD Dalhousie Refresher February 2010 Disclosure David Gardner Research/ Department of Health, NS development NSHRF projects: Pfizer Honouraria (expert/ speaker): AstraZeneca Canadian Pharmacists Association Mental Health Commission of Canada Michael Allen Department of Health, NS Health Canada Canadian Optimal Medication Prescribing and Utilization Service (COMPUS) 2 Objectives Introduce the KATIE program Raise your awareness about the importance of understanding basic terms that express therapeutic effects 3 4 A Pervasive Concern Continuing Medical Education often fails to lead to practice change. Awareness The KATIE Program because sometimes knowledge needs a translator Objective To narrow the knowledge-to-action gap by improving the effectiveness of continuing education and related activities. Acceptance Adop2on Weinert et al Curr Opin Crit Care 2008 Green & Seifert. J Am Board Fam Pract The KATIE Program prioritizes the learner s role in achieving this objective. 6 1

2 Knowledge Translation has gone from country peasant to royalty Knowledge Translation a.k.a Knowledge-to-Action Research Phase I-IV Action evaluation Information dissemination Action implementation Information filtering and synthesis Action planning s er id ls ov a p r du ts e vi en n s ic di s rv in inic rtm tio l pa iza Se c de gan ers rs or ak ato m y str lic ini Po dm A Knowledge exchange 7 8 The KATIE Program Knowledge Translation because sometimes knowledge needs a translator a.k.a Knowledge-to-Action Method Social marketing to effect a change in learning culture Targets: Learners Presenters/CME developers 9 10 More of Less of Less of Can you use this in your prac2ce? How? More of More of

3 What the KATIE Program IS What the KATIE Program is NOT A transformational influence that: Supports physicians and pharmacists in making the most of their learning activities Promotes presenters and learners to focus on appraising and applying new information To be used in any learning situation Conference Evening presentation One-on-one meetings Readings NOT a certification or approval program of CME content or speakers NOT an activity that occurs only in formal learning settings NOT a course in critical appraisal NOT a course in statistics This is a KATIE approved program Enduring KATIE is a Collaborative Program KATIE Program Components and Activities 1. The KATIE Card The appraisal/apply KT aid and reminder 2. Katie on the 52 Crosstown The unorthodox critical appraisal teaching series 3. CME Programs: Drug Evaluation Unit GRAPHIC DESIGN O HALLORAN DESIGN JOHN SHAW 15 An enduring presence of simple messages, reminder icons 4. KATIE for speakers To enhance CE learning and meaningful dialogue: learners presenters An knowledge-to-action aid and reminder: Emphasis on Critical appraisal ( should ) Application ( how ) CE Programs: Copies available Content integrated Aid for presenters

4 Who Follow Up Drop- Outs s Risks Numbers Missing Worth Str. of Evidence Compared to Big Picture Believability Mr. Edwards learns about Chance Torturing Numbers 19 The KATIE Program THEMES & ICONS 20 Marketing 101 When you see this image, what thoughts come to mind? Marketing 101 Marketing 101 Performance Jokes Safety Butt of jokes

5 What about these? Marketing 101 Woman with butterfly 25 Appraise Apply Don t know? Just ask 26 Feedback Program developers: Michael Allen David Gardner Tanya Hill Pam McLean- Veysey Andrea Murphy Glenn Rodrigues Visit our booth Complete the Refresher s evaluation Participate in upcoming surveys, focus groups, or workshops February Refresher Focus Group: Friday, 7:00 8:15 Workshop: Friday, 10:30 12: Corinne Tobin Epidemiology Over to you Mike 30 5

6 Risk Risk is the probability of an event or outcome occurring, e.g., Death Myocardial infarction Stroke Healing of ulcers Risk Risk is the probability of an event or outcome occurring Probability is number between 0 and 1 or a percentage 0.4 or 40% Risk sometimes referred to as event rate Risk Event occurs in 400 out of 1000 persons Risk = 400/1000 = 0.4 or 40% In a randomized controlled trial Relative risk = risk in study group / risk in placebo group Relative Risk Risk in study group / risk in placebo group Drug disease in 100 / 1000 people Risk = 0.1 or 10% Placebo disease in 400 / 1000 people Risk = 0.4 or 40% Relative risk = 0.1 / 0.4 = 0.25 or 25% Relative risk reduction = 1 minus relative risk 1 minus 0.25 = 0.75 or 75% Efficacy or Percent of events prevented Absolute Risk Reduction Relative risk = Risk in study group / risk in placebo group Relative risk reduction = 1 minus relative risk (percent of events prevented) Absolute risk reduction = Risk in study group minus risk in placebo group Relative vs absolute values Drug disease in 100 / 1000 people = 10% PBO disease in 400 / 1000 people = 40% Relative risk = 10/40 = 0.25 or 25% Relative risk reduction = = 75% Risk Absolute risk reduction = 40% - 10% = 30% Number needed to treat = 1/ARR = 1/0.3 =

7 Relative vs absolute values Drug disease in 10 / 1000 people = 1% PBO disease in 40 / 1000 people = 4% Relative risk = 1/4 = 0.25 or 25% Relative risk reduction = = 75% Absolute risk reduction = 4% - 1% = 3% Risk Number needed to treat = 1/ARR = 1/0.03 = 33 Relative vs absolute values 1000 patients in placebo and drug group Events / percent PBO Drug RRR ARR NNT % 40 4% % 75% 30% % 75% 3% Number Needed to Treat - NNT The number of patients who need to be treated to prevent one bad outcome. If NNT is 10 Have to treat 10 patients in order to prevent 1 bad outcome OR 1 in 10 people will benefit Important to know the period of time. Generally, should not extrapolate beyond period of the study Number Needed to Treat What s a good NNT? Depends Severity of outcome Cost of the drug Adverse effects of the drug Duration of therapy Ideal is NNT = Number Needed to Treat Condition Intervention Events prevented Time NNT DBP Antihypertensives Death, stroke, MI 1.5 yrs 8 DBP Antihypertensives Death, stroke, MI 5.5 yrs 128 Mild to mod Donepezil vs PBO No functional 1 yr 7 Alzheimers 1 decline Relative vs absolute values Number needed to treat - NNT The inverse of the absolute risk reduction If ARR = 10% NNT = 1 / 0.1 = 10 If ARR = 1.0% NNT = 1 / 0.01 = 100 Dyslipidemia Statins CHD death or MI 5 yrs 57 primary prvn 2 1 Evidence-based Medicine 3 rd Edition Dalhousie Academic Detailing Service

8 Relative vs absolute values 95% confidence interval Relative Odds ratios OR Hazard ratios HR Relative risk RR Relative risk reduction RRR Absolute Absolute risk reduction ARR Number needed to treat NNT A range of values within which we can be 95% sure that the true value lies Corresponds to a p-value of 0.05 but provides estimate of precision For ratios (odds ratio, hazard ratio, rel risk) If the CI includes 1, result is not statistically significant % confidence interval For ratios If the CI includes 1, result is not statistically significant Relative risk of MI = 0.80; 95% CI 0.65 to 1.1 Not sig Relative risk of MI = 0.80; 95% CI 0.65 to 0.90 Sig 95% confidence interval Wide confidence interval Indicates wide variation in result Less confident in result Often a result of small sample size Think about this RCT s: non-fatal myocardial infarction and death from coronary heart disease Subjects: No history of coronary heart disease (primary prevention). Duration: 3.3 years N: 5100 patients in the control and 5100 patients in the drug group The patient characteristics are: 80% male mean age = 63 yrs. mean blood pressure = 164/95 ASCOT Lancet 2003;361: What is your interpretation of the following results? How likely might you be to prescribe the drug based on each one? 1. The drug led to a 36% decrease in the incidence of non-fatal MI and CHD death (relative risk reduction). 2. The drug decreased the rate of non-fatal MI and CHD death from 3.0% to 1.9%, an absolute risk reduction of 1.1%. 3. You would have to treat 94 patients for 3.3 years to prevent one non-fatal MI or a death from CHD (number needed to treat). 4. The 95% confidence intervals around the previous result (ie, treat 94 patients for 3.3 years to avoid one non-fatal MI or CHD death) are 60 and At the end of 3.3 years, 97.0% of patients who don't take the drug will remain free of a cardiac event and 98.1% of patients who take the drug will remain free of a cardiac event (inverse absolute RR)

9 Patients not having MI or dying - Placebo Patients having MI or CHD death Patients NOT having MI or CHD death 49 Patients not having MI or dying - Drug Patients having MI or CHD death Patients NOT having MI or CHD death 50 CARDS Lancet 2004 ASCOT Lancet 2003 Shingles Prevention Study Results Event rate Placebo Zostavax RRR ARR Time (Yrs) NNT 95% CI Herpes zoster 3.3% 1.6% 51% 1.7% 4 yrs PH neuralgia 0.42% 0.14% 66% 0.3% 4 yrs % relative risk 36% relative risk Absolute risk reduction in stroke reduction in reduction nonfatal MI and fatal stroke 1.3% in 95% CI 11% to 69% CHDNNT 77 (42 to 424) Absolute risk reduction 1.1% in non-fatal MI and fatal CHD NNT=94 (60 to 215) 51 Lyle NEJM 2007;357: Atorvastatin: primary prevention Atorvastatin: primary prevention Placebo Event rate Atorv RRR ARR Time (Yrs) NNT 95% CI Placebo Event rate Atorv RRR ARR Time (Yrs) NNT 95% CI CHD Death Non-fatal MI 3.0% 1.9% 35% 1.1% 3.3 yrs CHD Death Non-fatal MI 3.0% 1.9% 35% 1.1% 3.3 yrs Stroke 2.8% 1.5% 46% 1.3% 3.9 yrs Stroke 2.8% 1.5% 46% 1.3% 3.9 yrs ASCOT Lancet 2003; CARDS Lancet (Condition s being studied) Percent of people in placebo and drug group having the outcome Relative risk reduction (Efficacy or percent of cases prevented) Absolute risk reduction (Event rate in placebo minus event rate drug) Number needed to treat (Number of people we must treat to prevent one 54 outcome event) 9

10 Shingles Prevention Study Results Placebo Event rate Zostavax Herpes zoster 3.3% 1.6% PH neuralgia 0.42% 0.14% RRR ARR 51% 1.7% 66% 0.3% Time (Yrs) 3.1 yrs 3.1 yrs NNT 95% CI ARBs - Reductions in HF Hospitalizations Event rate 24% vs 20% - Hosps RRR 18% ARR 4% NNT 23 (14 41) 3.5 yrs (Condition s being studied) Percent of people in placebo and drug group having the outcome Relative risk Absolute Number reduction risk needed to treat (Efficacy or reduction (Number of percent of (Event rate people we cases in placebo must treat to prevented) minus prevent one 55 Lyle NEJM 2007;357: event rate outcome drug) event) Pfeffer MA et al. Lancet 2003;363: ;345: Cohn JN et al. N Engl J Med 56 Questions to ask Is that relative risk reduction or absolute risk reduction? What is the number needed to treat? Over what period of time? What are the 95% confidence intervals? More information PPT templates and Excel calculator Workshop Friday at Questions? 10