Values and Preferences in Clinical Practice Guidelines

Gordon Guyatt

Clarity Research Group McMaster University

Plan

what is the problem?what is the problem?

whose values and preferences?whose values and preferences?

how can we find out about values how can we find out about values and preferences?and preferences?

applying best estimates of V and Papplying best estimates of V and P

What is the problem?

almost all decisions/recommendations almost all decisions/recommendations involve tradeoffsinvolve tradeoffs

benefits versus harms, burden, costs antithrombotic therapy

thrombosis reduction vs bleeding, burden, costs

tradeoffs require V and P judgments value reducing MI, stroke, DVT vs bleed and

burden

Whose values and preferences?

guideline panel membersguideline panel members

health care providershealth care providers

policy makerspolicy makers

subjects of the guidelinesubjects of the guideline patientspatients general publicgeneral public

How to determine patient values and preferences?

systematic review of patient V and Psystematic review of patient V and P

use guideline panel members use guideline panel members act as proxies for their patientsact as proxies for their patients’’ V and P V and P

patients on panelpatients on panel

collect own values and preferences collect own values and preferences datadata

Systematic review comprehensive searchcomprehensive search

48 studies48 studies 16 a fib, 10 stroke or MI, 5 VTE, 17 burden16 a fib, 10 stroke or MI, 5 VTE, 17 burden

higher disutility on stroke than gastrointestinal higher disutility on stroke than gastrointestinal bleed and much greater disutility on stroke bleed and much greater disutility on stroke than on treatment burdenthan on treatment burden

example of the relative value of health states:example of the relative value of health states: a reasonable trade-off between nonfatal stroke and a reasonable trade-off between nonfatal stroke and

bleeds is a ratio of disutility of 2.1 to 3.1bleeds is a ratio of disutility of 2.1 to 3.1

Using systematic review results systematic review results require systematic review results require

interpretationinterpretation

how should guideline panel proceed?how should guideline panel proceed?

systematic V and P rating exercisesystematic V and P rating exercise

ACCPACCP consider systematic review consider systematic review make ratings for typical patientsmake ratings for typical patients rate scenarios, time frame of one yearrate scenarios, time frame of one year

13

Dead

Full Health

Feeling thermometer:Venous limb gangrene

Minimum

Maximum

Mean

Disutility with stroke in a child

Physical Symptoms 

Your child suddenly becomes unresponsive Your child is unable to move one arm and one leg Your child cannot speak to you

Mental Symptoms 

Your child is irritable and upset You find it difficult to console your child Family and friends find the diagnosis difficult to

accept

Pain Your child has a headache for a number of days Recovery

Your child’s stay in hospital is prolonged Your child recovers some function, including speech

and movement slowly over weeks to months Your child complains of tiredness for months Your child needs help to attend normal school Your child has multiple hospital visits for

physiotherapy and rehabilitation You must alter your hopes and dreams for your child’s

futureFurther Risk 

You are told your child is not at risk of further strokes, You find your child’s ongoing limitations very hard to

accept

14

15

Dead

Full Health

Feeling thermometer:Major stroke in a child

Minimum

Maximum

Mean

Disutility with a gastrointestinal bleed

Symptoms

You feel nauseated and unwell for two days, and then suddenly you vomit blood and feel faint.

Diagnostic tests and treatment

You are taken by ambulance to a busy emergency department. An intravenous catheter is placed and a catheter is placed

through your nose into your stomach to help drain the blood You receive blood transfusions to replace the blood you lost You are admitted to hospital A doctor puts a tube down your throat into your stomach to see

where you are bleeding from and to provide treatment You receive sedation by intravenous to ease the discomfort of

the test You do not require an operation to stop the bleeding You must stop taking your blood thinner; stopping the blood

thinner puts you at risk of developing a new blood clot.Recovery

You stay in the hospital for a few days You feel much better at the end of your hospital stay You need to take pills for the next six month to prevent further

bleeding After that, you are back to normal About 2 weeks after your bleeding you restart your blood

thinning therapy – you worry every day about more bleeding for the first month after restarting

After that, your worry gradually decreases

16

17

Dead

Full Health

Feeling thermometer:Gastrointestinal bleed

Minimum

Maximum

Mean

Key decisions

myocardial infarction = pulmonary myocardial infarction = pulmonary embolus = venous thrombosis = embolus = venous thrombosis = gastrointestinal bleedgastrointestinal bleed

stroke = 3 bleeds (and thus three stroke = 3 bleeds (and thus three of any other major event)of any other major event)

What lowers strength of recommendation?

strong recommendationstrong recommendation confident more good than harmconfident more good than harm almost all informed patient make same choicealmost all informed patient make same choice

tight balancetight balance uncertainty about typical V and Puncertainty about typical V and P uncertainty about variability in V and Puncertainty about variability in V and P

V and P highly variableV and P highly variable

Strong recommendation for Strong recommendation for warfarinwarfarin

Alternatives: experience of clinicians in shared decision making

Patients on panel

often advocatedoften advocated

may be useful in issues overlookedmay be useful in issues overlooked

no guarantee reflects typical V and Pno guarantee reflects typical V and P

V and P can help if disagreementestablish that everyone agrees with

evidence summary

clarify values and preferences

Review evidence about patient V and P

Conclusions

value and preference judgments ubiquitous

panels MUST make judgments explicit quantitation desirable values those who bear consequences weak recommendation more likely

close trade-off uncertainty in typical V and P highly variable V and P

Conclusions

systematic review of V and P – routinesystematic review of V and P – routine

still need panel input still need panel input study results require interpretationstudy results require interpretation results likely incompleteresults likely incomplete

structured elicitation of panel V and Pstructured elicitation of panel V and P

patients on panel – questionablepatients on panel – questionable

expert panel shared decision-makingexpert panel shared decision-making