TEC: Evidence Based Therapeutics
Therapeutics Education Collaboration
Medication Mythbusters – Home of the Best Science (BS) Medicine Podcast

Episode 4: De-constructing Risk (or Benefit)

In our fourth installment, we apply the absolute benefit for statin therapy to our patient. We discuss the absolute benefits in context of the individual risk and acknowledge that when translating pooled literature numbers to individual patients an element of mysterious uncertainty always remains (except for James who knows but won’t tell and Mike who doesn’t know but tells us he does).

Show Notes

Definitions

CVD is cardiovascular disease and typically refers to the combination of CHD (coronary heart disease – fatal and non-fatal MIs and sometimes angina) PLUS cerebrovascular disease (fatal and non-fatal strokes – and sometimes TIAs) PLUS (sometimes) other conditions (heart failure, peripheral vascular disease)

Calculating benefit

  1. Change the factor and recalculate the chance of CVD
  2. Use the relative benefits seen in clinical trials (typically 5 years in duration) and apply them to the chance calculated for your patient
  3. Avoid the use of CDV calculators and just use the absolute benefits seen in clinical trials

A synopsis of the relative benefit of drugs

  • Statins ? 30%? in CHD (0%? in women)? 5 years
  • BP ? 40 %? in strokes and ? 20%? in CHD ? 5 years
  • Metformin ? 35%? in CHD and stroke ? 8-10 years

A synopsis of the absolute benefit of drugs

Statins over 5 years in a post MI patient Coronary events ?4% (15% to 11%) Death ?2% (12% to 10%) Strokes ?1% (5% to 4%) Treating a Blood Pressure of 160 /100 mmHg for 5 years CVD ? 1% (4% to 3%)

Absolute benefit of statins over approx 5 years

Major coronary events (%)* Death (%) Strokes (%) FROM WHAT CVD TO WHAT CVD (%)
Primary 1-1.5* 8-9 to 7
Diabetes 2 1-1.5 10 to 7
Secondary 4 2 1 20 to 15

* just in males and NO difference in overall serious adverse events

Episode 3: The Risky Business of CVD Risk Assessment

In the third session, we discuss the advantages and disadvantages of three methods to present “benefit”: changes in risk calculators, using relative risk, or the absolute benefit. We review the challenges of absolute vs relative risk (or relative vs absolute truth) and discuss patient expectations in regards to the medical miracle of prevention. The duration of therapy is put in context of the epoch time frames of risk calculators and studies.

Show Notes

Definitions

CVD is cardiovascular disease and typically refers to the combination of CHD (coronary heart disease – fatal and non-fatal MIs and sometimes angina) PLUS cerebrovascular disease (fatal and non-fatal strokes – and sometimes TIAs) PLUS (sometimes) other conditions (heart failure, peripheral vascular disease)

Calculating benefit

  1. Change the factor and recalculate the chance of CVD
  2. Use the relative benefits seen in clinical trials (typically 5 years in duration) and apply them to the chance calculated for your patient
  3. Avoid the use of CDV calculators and just use the absolute benefits seen in clinical trials

A synopsis of the relative benefit of drugs

  • Statins ? 30%? in CHD (0%? in women)? 5 years
  • BP ? 40 %? in strokes and ? 20%? in CHD ? 5 years
  • Metformin ? 35%? in CHD and stroke ? 8-10 years

A synopsis of the absolute benefit of drugs

Statins over 5 years in a post MI patient Coronary events ?4% (15% to 11%) Death ?2% (12% to 10%) Strokes ?1% (5% to 4%) Treating a Blood Pressure of 160 /100 mmHg for 5 years CVD ? 1% (4% to 3%)

  • Therapeutics Letter #62.
  • Absolute benefit of statins over approx 5 years

    Major coronary events (%)* Death (%) Strokes (%) FROM WHAT CVD TO WHAT CVD (%)
    Primary 1-1.5* 8-9 to 7
    Diabetes 2 1-1.5 10 to 7
    Secondary 4 2 1 20 to 15

    * just in males and NO difference in overall serious adverse events

    Episode 2: Evidence does not equal decision-making

    In our second session we discuss the philosophy of calculating risk and the many factors that influence the application of these numbers. We each calculate risk using our personal preference for risk estimators and discuss the mystery of why these numbers are not the same. “Treating” asymptomatic patients and instituting preventive interventions taken for a life time does not require great haste.

    Show Notes

    Canadian Cardiovascular Society Risk Calculator

    12 points =10% risk in 10 years (of non-fatal MI or coronary death)

    Risk factors Points
    Age 3
    Total cholesterol 6
    HDL 2
    BP 1
    Smoke 0
    TOTAL 12

    Can J Cardiol 2006;22(11):913-27

    Our 45 y/o 10-year risk

    Framingham
    10 year chance of CVD
    Overall CVD 14.1%
    CHD 12.3%
    MI 6.4%
    Stroke 1.2%
    Death of CVD 2.0%
    Death for CHD 2.0%

    Episode 1: Philosophy, guidelines and the truth

    In this first session we offer a slightly long introduction (but not long enough to reach REM sleep). We present Mr. Guy Lines, a 45 year old male with a number of risks for cardiovascular, who we will consider over the next number of sessions on primary prevention. We lay the rocky groundwork of future podcasts; touching on patient values, the arbitrary nature of guidelines, discussing risks, the asymptomatic ‘sick’ patient, and the art (or enigma) of applying the evidence.

    Show Notes

    Hippocrates would be proud?

    Mr G. Lines is a 45 year old male in for his “periodic” health exam. He describes himself as happy and healthy Aside from reminding him to wear a seatbelt, floss regularly, etc, you find…

    1. He is relieved to hear routine rectal exams don’t start until age 50
    2. His BP is 146/85 today (you took it twice hoping it would be below 140)
    3. His BMI=29 and his WC=98 cm
    4. His Lipids: Total Cholesterol = 6.8/265, HDL = 1.0/39, LDL = 4.9/191, Trig = 2/312
    5. His Blood Sugar = 6.4/115
    6. He is not a smoker

    See List of All Podcast Episodes

    Search

    Upcoming Events

    Practical Evidence for Informed Practice (PEIP) – October 22-23, 2021

    This will be a live-streamed course from Edmonton, AB. Registration Opens August 2021

    BS Medicine Podcast

    BedMed: The High Blood Pressure Study

    This pragmatic trial is now recruiting in BC. Make a difference and get involved with pragmatic trials (www.pragmatictrials.ca)

    PEER Tools