Values and Preferences in Clinical Practice Guidelines Gordon Guyatt Clarity Research Group McMaster University

Plan  what is the problem?  whose values and preferences?  how can we find out about values and preferences?  applying best estimates of V and P

What is the problem?  almost all decisions/recommendations involve 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

What are values and preferences? judgments of disutility judgments of disutility ▪ burden or negative outcomes associated with a particular health state “a broad term that includes patient perspectives, beliefs, expectations, and goals for their health and life, including the process that patients go through in weighing the potential benefits, harms, costs, and burdens associated with different treatments or disease management options” “a broad term that includes patient perspectives, beliefs, expectations, and goals for their health and life, including the process that patients go through in weighing the potential benefits, harms, costs, and burdens associated with different treatments or disease management options”

What have guideline panels done in the past ?  ignored  unaware that making V and P judgments  implicit, unconscious V and P of panelists  remains least understood, most poorly practiced area of guideline development

Whose values and preferences?  guideline panel members  health care providers  policy makers  subjects of the guideline  patients  general public

How to determine patient values and preferences?  systematic review of patient V and P  use guideline panel members  act as proxies for their patients’ V and P  patients on panel  collect own values and preferences data

Systematic review  comprehensive search  48 studies  16 a fib, 10 stroke or MI, 5 VTE, 17 burden  higher disutility on stroke than gastrointestinal bleed and much greater disutility on stroke than on treatment burden  example of the relative value of health states:  a reasonable trade-off between nonfatal stroke and bleeds is a ratio of disutility of 2.1 to 3.1

Systematic review, continued  little consistency in health state preferences  contributing factors?  measurement methods (understanding)  prior experience with the treatment  description of event  prior experience with adverse event, example stroke  cause of the adverse event: treatment-related versus “natural”; higher value avoiding treatment-induced events than avoiding events treatment prevents  age, sex

Using systematic review results  systematic review results require interpretation  how should guideline panel proceed?  systematic V and P rating exercise  ACCP  consider systematic review  make ratings for typical patients  rate scenarios, time frame of one year

Venous limb gangrene scenario Physical You suddenly develop severe pain in the leg where you have your blood clot and your toes start to turn black. You suddenly develop severe pain in the leg where you have your blood clot and your toes start to turn black. Treatment You have to stay in hospital. You have to stay in hospital. You stop taking warfarin. You stop taking warfarin. The swelling in your leg gets worse and the pain is severe. The swelling in your leg gets worse and the pain is severe. You receive a new blood thinner through your intra-venous line You receive a new blood thinner through your intra-venous line Recovery After a few weeks, your toes return to normal. After a few weeks, your toes return to normal.

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 future Further 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 embolus = venous thrombosis = gastrointestinal bleed  stroke = 3 bleeds (and thus three of any other major event)

What lowers strength of recommendation?  strong recommendation  confident more good than harm  almost all informed patient make same choice  tight balance  uncertainty about typical V and P  uncertainty about variability in V and P  V and P highly variable

 Strong recommendation for warfarin

Alternatives: experience of clinicians in shared decision making

Patients on panel  often advocated  may be useful in issues overlooked  no guarantee reflects typical V and P

 establish 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 – routine  still need panel input  study results require interpretation  results likely incomplete  structured elicitation of panel V and P  patients on panel – questionable  expert panel shared decision-making