EBM 2.0EBM 2.0Incorporating values and preferences Incorporating values and preferences

in clinical decision makingin clinical decision making

Gordon GuyattCLARITY research group, McMaster University

Gordon GuyattCLARITY research group, McMaster University

Patient Values in Patient Values in Clinical Decision-Clinical Decision-

makingmaking• EBM and the role of patient valuesEBM and the role of patient values

• patient values and physician patient values and physician valuesvalues

• how might we ensure decisions how might we ensure decisions reflect patient values?reflect patient values?

Principles of EBM

1. for optimal decision-making, need systematic summary of best evidence

2. hierarchy of evidence

3. evidence is never sufficient for decision-making

• antibiotics for pneumococcal pneumonia?

• 95 year old man, severely demented, incontinent, contracted, lives in long-term care facility contracts pneumococcal pneumonia.

• treat with antibiotics?

Clinical decision-making Clinical decision-making 20102010

Research evidence

Patient valuesand preferences

Clinical state and circumstances

ExpertiseExpertise

Comparison of patient and Comparison of patient and physician valuesphysician values

• to anticoagulate or not to anticoagulate to anticoagulate or not to anticoagulate patients with atrial fibrillation: patients with atrial fibrillation: differences between physician and patient differences between physician and patient perspectivesperspectives– Devereaux PJ et. al., BMJ, 2001Devereaux PJ et. al., BMJ, 2001

• face to face interview of 63 physicians face to face interview of 63 physicians and 61 patientsand 61 patients

• probability trade-off tool to determine probability trade-off tool to determine and compare physician and patient and compare physician and patient thresholds for how much stroke reduction thresholds for how much stroke reduction is necessary and how much bleeding risk is necessary and how much bleeding risk is acceptable for antithrombotic therapy is acceptable for antithrombotic therapy in atrial fibrillationin atrial fibrillation

Devereaux et. al., Devereaux et. al., 20012001

• patients with atrial fibrillation at high risk patients with atrial fibrillation at high risk of strokeof stroke

• warfarin decreases risk at cost of increased gi warfarin decreases risk at cost of increased gi bleedsbleeds

• without treatment 100 patients will suffer:without treatment 100 patients will suffer:– 12 strokes (six major, six minor), 3 serious gi bleeds 12 strokes (six major, six minor), 3 serious gi bleeds in 2 yearsin 2 years

• warfarin would decrease strokes in 100 patients warfarin would decrease strokes in 100 patients to 4 per 2 years (8 fewer strokes, 4 major, to 4 per 2 years (8 fewer strokes, 4 major, minor)minor)

• how many bleeds would you accept in 100 patients how many bleeds would you accept in 100 patients over two years, and still be willing to over two years, and still be willing to administer/take warfarin?administer/take warfarin?

STROKES CAN BE MINOR OR MAJOR IN SEVERITY

MINOR STROKE MAJOR STROKE PHYSICAL SYMPTOMS

MENTALSYMPTOMS

PAIN

RECOVERY

FURTHER RISK

IF YOU HAVE A STROKE, YOUR CHANCE OF HAVING A MINOR OR MAJOR STROKE ARE EQUAL

- You suddenly cannot move or feel one arm and one leg

- You are unable to fully understand what is being said to you- You have difficulty expressing yourself

- You feel no physical pain

-You are admitted to hospital-Your weakness, numbness and problem with understanding improve but you still feel slightly weak or numb in one arm and one leg-You are able to do almost all the activities you previously did before the stroke-You can function independently

- You have an increased risk of having more strokes

- You suddenly are dizzy and blackout- You are unable to move one arm and one leg- You cannot swallow or control bladder and bowel

- You are unable to understand what is being said- You are unable to talk

- You feel no physical pain

-You are admitted to hospital-You cannot dress-The nurse feeds you-You cannot walk-After 1 month with physiotherapy, you are able to wiggle your toes and lift your arm off the bed-You remain this way for the rest of your life

- Another illness will likely cause your death

SEVERE BLEEDING

AN EXAMPLE OF THIS IS A STOMACH BLEED

PHYSICAL

TREATMENT

RECOVERY

- You feel unwell for two days then suddenly you vomit blood

-You are admitted to hospital-You stop taking warfarin-A doctor puts a tube down your throat to see where you are bleeding from-You receive sedation to ease the discomfort of the test-You do not need an operation-You receive blood transfusions to replace the blood you lost

-You stay in hospital one week-You feel well at the end of your hospital stay-You need to take pills for the next six months to prevent further bleeding-You do not take warfarin any more-After that you are back to normal

Devereaux et. al., Devereaux et. al., 20012001

• patients with to atrial fibrillation at high patients with to atrial fibrillation at high risk of strokerisk of stroke

• warfarin decreases risk at cost of increased gi warfarin decreases risk at cost of increased gi bleedsbleeds

• without treatment 100 patients will suffer:without treatment 100 patients will suffer:– 12 strokes (six major, six minor), 3 serious gi bleeds 12 strokes (six major, six minor), 3 serious gi bleeds in 2 yearsin 2 years

• warfarin would decrease strokes in 100 patients warfarin would decrease strokes in 100 patients to 4 per 2 years (8 fewer strokes, 4 major, to 4 per 2 years (8 fewer strokes, 4 major, minor)minor)

• how many bleeds would you accept in 100 patients how many bleeds would you accept in 100 patients over a year, and still be willing to over a year, and still be willing to administer/take warfarin?administer/take warfarin?

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

MAXIMUM NUMBER OF ACCEPTABLE EXCESS BLEEDS

NU

MB

ER

OF

PH

YS

ICIA

NS

/PA

TIE

NT

S

Physicians N=63

Patients N=61

PHYSICIAN AND PATIENT BLEEDING THRESHOLDS FOR WARFARIN

Is this real?Is this real?• retrospective review through record linkage across retrospective review through record linkage across

population based databases in Canadapopulation based databases in Canada• 530 MDs cared for:530 MDs cared for:

– 3120 afib patients with warfarin bleed 3120 afib patients with warfarin bleed (intracraneal or GI)(intracraneal or GI)

– for a patient with afib 90 days prior to bleedfor a patient with afib 90 days prior to bleed– for a patient with afib 90 days after the eventfor a patient with afib 90 days after the event– (some of these MDs also cared for patients up 1 y (some of these MDs also cared for patients up 1 y post)post)

– 90% of patients were at high risk for afib-related 90% of patients were at high risk for afib-related strokestroke

• how likely are patients seen how likely are patients seen afterafter an afib patient an afib patient bled while on warfarin to receive a warfarin bled while on warfarin to receive a warfarin prescription (compared to those seen 90 days prescription (compared to those seen 90 days beforebefore the bleed)?the bleed)?

Likelihood of warfarin prescriptionLikelihood of warfarin prescription

1.0

0.79 (0.62-1.00)

0.60 (0.46-0.69)

0.61 (0.46-0.81)

0.72 (0.54-0.97)

1.00 90 d prior

0-90 d post

91-180 d post

181-270 d post

271-360 d post

Odds ratio (95% CI)

Less warfarin after bleeding

Days relative to bleed

ConclusionsConclusions

• average patient preferences/values differ average patient preferences/values differ from average physician preferencesfrom average physician preferences– if physician values determine the decision, if physician values determine the decision, patients won’t get what they wantpatients won’t get what they want

• physician values/preferences differphysician values/preferences differ– if physician preferences determine decisions, if physician preferences determine decisions, then your treatment depends on your physicianthen your treatment depends on your physician

• patient values/preferences differpatient values/preferences differ– if use average patient preferences, many if use average patient preferences, many patients won’t get what they wantpatients won’t get what they want

Giving patients what they Giving patients what they wantwant

• traditional methodstraditional methods

• decision aidsdecision aids– decision boardsdecision boards– decision bookletsdecision booklets– flip chartsflip charts– videosvideos– audiotapesaudiotapes– computerized decision instrumentscomputerized decision instruments

Do decision aids work?Do decision aids work?• systematic review of 34 RCTs

• compared to usual care, decision aids:– increased patient participation in

decision making (RR 1.4, 95% CI: 1.0-2.3)

– improved patient knowledge (19, 95% CI 13-24, points out of 100 in knowledge surveys)

– reduced decisional conflict (9.1 of 100, 95%CI: 6-12)

ConclusionsConclusions• health care provider and patient health care provider and patient values influence decision making and values influence decision making and the two are not always the samethe two are not always the same

• decision aids decision aids – lead to more certain and informed lead to more certain and informed decisions decisions

– increase knowledge about treatment options increase knowledge about treatment options and outcomesand outcomes

– in some instances lead to decreased in some instances lead to decreased preferences for interventions, therapies, preferences for interventions, therapies, and screeningand screening