Clinical Decision-making: Why evidence is never sufficient • EBM and the role of patient values • physician values and life or death decisions • patient values and physician values
Treatment of pneumonia • do antibiotics help in pneumococcal pneumonia? • 95 year old man, severely demented, incontinent, contracted, lives in long-term care facility • contracts pneumococcal pneumonia
Patient dilemma Ask
Acquire
Hierarchy of evidence
Act
Appraise Evidence is not enough Apply
Clinical decision-making 2009 Patient values and preferences
Clinical state and circumstances
Expertise
Research evidence
Case • 75 y/o female admitted to the ICU with urosepsis 10 days ago. She now requires two inotropes to maintain a mean arterial pressure of 80 mm HG, is ventilator dependent, comatose, and in acute oliguric renal failure. Her APACHE II score is 38, suggesting a 10% chance of survival. Her past history includes long-standing depression, responsive to treatment. She has been walking with a cane due to a chronic deformity from polio.
• She used to run the family manufacturing business, which involved supervision of 10 people. Until just before admission, she continued to do the bookkeeping for the firm. She is single and lives alone in her own home. There are no known written or verbal advance directives. The patient has an older brother living in the United States, with whom she has not spoken for years, and whose current whereabouts are not known. There are no other living relatives. A few friends visit her in the ICU, but none want to be involved in decisions regarding her medical care.
Management strategies • 1. D/C inotropes and ventilator but continue comfort measures • 2. D/C inotropes and other maintenance therapy but continue ventilator and other comfort measures • 3. Continue with current management but add no new therapeutic interventions • 4. Continue with current management, add further inotropes, change antibiotics, and the like as needed, but do not start dialysis • 5. Continue with full aggressive management and plan for dialysis if necessary
Withdrawal of life support Cook, Guyatt, JAMA. 1995
• Cross sectional survey • Staff from 37 university affiliated hospitals in 8 provinces • 1361 ICU health care workers completed the survey – – –
149 of 167 ICU attending staff 142 of 173 ICU house staff 1070 of 1455 ICU nurses
• Overall participation rate 76%
Case Development • cases scenarios, variable factors
patient’s age (45 vs 75) prior cognitive function (highly functional vs alzheimer’s) – likelihood of surviving current episode (50% vs 10%) – likelihood of long term survival (50% 1yr mortality breast CA vs no comorbidity affecting long term survival) – –
• fixed factors in the scenarios
– socioeconomic status – premorbid physical and emotional function – sex and employment
Comparison of patient and physician values • to anticoagulate or not to anticoagulate patients with atrial fibrillation: differences between physician and patient perspectives – Devereaux PJ et. al., BMJ, 2001
• face to face interview of 63 physicians and 61 patients • probability trade-off tool to determine and compare physician and patient thresholds for how much stroke reduction is necessary and how much bleeding risk is acceptable for antithrombotic therapy in atrial fibrillation
Devereaux et. al., 2001 • patients with to atrial fibrillation at high risk of stroke • warfarin decreases risk at cost of increased gi bleeds • without treatment 100 patients will suffer:
– 12 strokes (six major, six minor), 3 serious gi bleeds in 2 years
• warfarin would decrease strokes in 100 patients to 4 per 2 years (8 fewer strokes, 4 major, minor)
STROKES
CAN BE MINOR OR MAJOR IN SEVERITY MINOR STROKE
MAJOR STROKE
PHYSICAL SYMPTOMS
- You suddenly are dizzy and blackout - You suddenly cannot move or feel one arm and one leg - You are unable to move one arm and one leg - You cannot swallow or control bladder and bowel
MENTAL SYMPTOMS
- You are unable to fully understand what is being said to you - You have difficulty expressing yourself
- You are unable to understand what is being said - You are unable to talk
PAIN
- You feel no physical pain
- You feel no physical pain
RECOVERY
-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 leave the hospital after one week
-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
FURTHER RISK
- You have an increased risk of having more strokes
- Another illness will likely cause your death
IF YOU HAVE A STROKE, YOUR CHANCE OF HAVING A MINOR OR MAJOR STROKE ARE EQUAL
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., 2001 • patients with to atrial fibrillation at high risk of stroke • warfarin decreases risk at cost of increased gi bleeds • without treatment 100 patients will suffer:
– 12 strokes (six major, six minor), 3 serious gi bleeds in 2 years
• warfarin would decrease strokes in 100 patients to 4 per 2 years (8 fewer strokes, 4 major, minor)
PHYSICIAN AND PATIENT BLEEDING THRESHOLDS FOR WARFARIN NUMBER OF PHYSICIANS/PATIENTS
40 35 30
Physicians N=63
25
Patients N=61
20 15 10 5 0 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
Is this real? • retrospective review through record linkage across population based databases in Canada • 530 MDs cared for: – 3120 afib patients with warfarin bleed (intracraneal or GI) – for a patient with afib 90 days prior to bleed – for a patient with afib 90 days after the event – (some of these MDs also cared for patients up 1 y post) – 90% of patients were at high risk for afib-related stroke • how likely are patients seen after an afib patient bled while on warfarin to receive a warfarin prescription (compared to those seen 90 days before the bleed)?
Likelihood of warfarin prescription Days relative to bleed
Odds ratio (95% CI)
90 d prior
1.00
0-90 d post
0.79 (0.62-1.00)
91-180 d post
0.60 (0.46-0.69)
181-270 d post
0.61 (0.46-0.81)
271-360 d post
0.72 (0.54-0.97) 1.0 Less warfarin after bleeding
Conclusions • average patient preferences/values differ from average physician preferences – if physician values determine the decision, patients won’t get what they want
• physician values/preferences differ
– if physician preferences determine decisions, then your treatment depends on your physician
• patient values/preferences differ
– if use average patient preferences, many patients won’t get what they want
Values + Preferences Patients’ perspectives, beliefs, expectations, and goals for health and life. Underlying processes used in considering the benefits, harms, costs, and inconveniences patients will experience with each management option and the resulting preferences for each option.
Parental or paternalistic model
Clinician offers minimal information about the options Clinician deliberates about relative merits of the options Clinician makes decisions without patient input NOT CONSISTENT WITH EBM!!!
Clinician as perfect agent model
Clinicians must assess patients values and preferences Clinicians, acting on their understanding of the patient’s best interest, make a recommendation
Informed decision making model
Patient receives information about options Patient deliberates and makes decision with minimal clinician input
Shared decision-making model
Patients and clinicians exchange information about options They both share information about their V+P They deliberate together Reach decision by consensus
Decision making models Approaches
Parental
Clinician-asShared perfect agent decision-making
Informed
Direction and amount of information flow about options
Clinician Patient
Clinician Patient
Clinician Patient
Clinician Patient
Direction of information flow about values and preferences
Clinician Patient
Clinician Patient
Clinician Patient
Clinician Patient
Deliberation
Clinician
Clinician
Clinician, Patient
Patient
Decider
Clinician
Clinician
Clinician, Patient
Patient
No when decision is not purely technical
Yes
Yes
Yes
Consistent with EBM principles
Giving patients what they want • traditional methods • decision aids – – – – – –
decision boards decision booklets flip charts videos audiotapes computerized decision instruments
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)
Conclusions • health care provider and patient values influence decision making and the two are not always the same • decision aids
– lead to more certain and informed decisions – increase knowledge about treatment options and outcomes – in some instances lead to decreased preferences for interventions, therapies, and screening