Life Goals and Health DecisionsLife Goals and Health DecisionsWhat will people live (or die) for?What will people live (or die) for?

Alan SchwartzGordon Hazen (NWU)

Ariel LeiferPaul Heckerling

Funded by grant SES-0451122 from the National Science Foundation (Decision, Risk, and Management Sciences) to Schwartz and Hazen, PIs. Mike Richards also assisted in data collection for this project.

OverviewOverview

What’s a QALY?How do we measure QALYs?What’s wrong with QALYs?How might knowing about life goals help?Which life goals really count?Now what?

What’s a QALY?What’s a QALY?

The most important method for evaluating health-related quality of life.

Central to medical decision and cost-effectiveness analyses.

A common metric that weights quantity and quality of life.

QALY definedQALY defined

lifetime remainingin stateshealth

ate)Quality(st*e)Years(statQALY

Quality() ranges from 0 (death) to 1 (perfect health)

For example:

•Two years of life in perfect health = 2 QALYs

•Four years of life in health quality 0.5 = 2 QALYs

How do we measure QALYs?How do we measure QALYs?

Subjectively querying patients, physicians, or community members.

Most common method: time-tradeoff utility assessment

Time-TradeoffTime-Tradeoff

Imagine your remaining life expectancy is 20 years

Imagine you’re going to spend those 20 years in a single sub-perfect health state, like blindness

Would you rather:Live for 20 years with blindnessLive for 16 years in perfect health

QALYsQALYs

If your Quality(blindness) = 0.60, and you expect to live 20 more years (12 QALYs):A medical treatment that would cure your

blindness would provide you with 8 additional QALYs

And you should prefer that treatment over extending your (blind) life by 10 years (6 QALYs)

What’s wrong with QALYs?What’s wrong with QALYs?

Tsevat (2000) notes that numerous studies have demonstrated that:The correlation between one’s current health

and the time-tradeoff utility for that health state is at best modest.

Willingness to trade away time is often much less than the general public, health care professionals, and even family members believe.

Unwillingness to trade offUnwillingness to trade off

Miyamoto and Eraker (1988) found that subjects might:accept a tradeoff of life duration for improved

health quality when remaining lifetime was long

but decline all tradeoffs if remaining lifetime was short.

Maximum endurable timeMaximum endurable time(Sutherland, et al. 1982, and others)(Sutherland, et al. 1982, and others)

Sometimes, people indicate they can tolerate no more than a particular time in an undesirable health state, beyond which each additional increment of time decreases overall utility.

Miyamoto et al. relate an instance of a patient who regarded his health state as almost intolerable, but who wanted to live at least 5 more years to see his son graduate from high school.

Quality of Quality of What?What?

In Robert Harling’s play Steel Magnolias, Shelby, a young diabetic woman chooses to put her health at risk by bearing a child, saying…

Quality of Quality of What?What?

Shelby illustrates a distinction pointed out by Tsevat (2000): a person’s willingness or unwillingness to trade away life years or accept a gamble involving life years is more a function of how the person values quality of life than quality of health.

Quality of Quality of What?What?

Several of the problems with QALYs can be explained – and even motivated – by noting that quality of life is more than quality of health

What issues are potentially relevant to quality of life?

Adding extrinsic goals to the QALY modelAdding extrinsic goals to the QALY model

Specifically, quality of life may also include attainment of relevant extrinsic goalsextrinsic here meaning: goals achievable at a specific

point in timeE.g. Shelby’s goal of having a child

For extrinsic goals, the level of goal achievement has importance that is unrelated to life duration.Shelby’s goal of bearing a child has value that is

independent of her length of life – having borne a child has the same value to Shelby whether she lives 5 or 15 or 30 years.

This value cannot be expressed in standard QALYs.

Examples of extrinsic life goalsExamples of extrinsic life goals

Shelby wants to bear a child; an author wants to complete a book; an athlete wants to compete in the Olympics; an artist wants to complete a major work; an engineer or architect hopes to see a building raised; a politician wishes to achieve higher office; a celebrity plans to write their memoirs; political activists seek campaign reform legislation; individuals seek the financial and social welfare of their

families.

How do life goals help?How do life goals help?

Extrinsic goals might account for lack of willingness to trade away time or take a gamble that might shorten life Why should an author trade away or risk time she needs to complete an

important work, for health quality improvements that do not affect her ability to write?

Maximum endurable time is sensible if one’s worse-than-death health state is compensated for by the ability to attain a goal in the near future.

Moreover, goal-related issues may impact the value structure appropriate for decision analyses. For instance, prophylactic oophorectomy is an option for women at high

risk for ovarian cancer; but this course of action negatively impacts the extrinsic goal of bearing children.

Our research programOur research program

1. Studies of life goals: create a taxonomy2. Develop new utility models that can incorporate

goal achievement, multiple goals3. Develop utility assessment procedures that are

goal-sensitive4. Repeat or simulate decision analyses with

goal-sensitive utilities5. Replicate unwillingness-to-trade studies and

ask whether goal differences can explain results6. Explore implications for societal cost-effectiveness

analyses

Phone survey: MethodsPhone survey: Methods

Fifty Chicago-area residentsContacted using random-digit dialing Interviewed by telephone, paid $25 Each respondent asked to generate:

Three goals they hoped to achieve within the next five years

One goal they hoped to achievewithin the next ten years

One goal they hoped to achieveduring their remaining lifetime.

Phone survey: MethodsPhone survey: Methods

For each goal, the respondent was askedhow long they thought the goal might take to

achieve, in years;whether they would prefer a shorter lifetime

with certain goal achievement to their full lifetime without goal achievement;

whether they would prefer lower quality of health with certain goal achievement to their full health without goal achievement.

Phone survey: AnalysisPhone survey: Analysis

Two investigators (AS and AL) independently reviewed the list of goals and developed taxonomic classifications. The classification systems were compared and each goal was reviewed by the two investigators jointly to resolve any disagreements.

Goal categories were then analyzed to determine whether the categorization could predict goals for which respondents would be significantly more willing to trade off either life or health for goal achievement.

Mixed logistic models were fitted with SAS PROC GENMOD to predict willingness to trade off from goal category; correlations in willingness to trade off within each subject were modeled assuming compound symmetry.

Goals232

Wealth59

Travel25

Personal Fulfillment

17

Professional54

Health & Fitness

21

Family50

Self28

Family Member

27

Job38

Retire16

Financial Security

28

Real Property

26

Personal Property

6

Education20

Taxonomy of GoalsTaxonomy of Goals

Results: Who will trade?Results: Who will trade?

Participants were willing to trade life years for goal achievement in 43% of goals, but were willing to trade health for goal achievement in only 29% of goals

Trading life years Considerable correlation for goals within subject (r = 0.42, p<.05) Women were significantly more likely to trade off life years than

men (OR = 2.49, 95% CI=[1.04, 2.95], p=0.04). No differences by age, race, or goal horizon (5 year, 10 year, life)

Trading health Considerable correlation in willingness to trade health for goals

within subject (r = 0.37, p<.05). No differences by gender, age, race, or goal horizon

Results: Trade to achieve what?Results: Trade to achieve what?

Goals categorized as family, wealth, professional, other. Controlling for goal category and interactions, women were

still significantly more likely than men to be willing to trade off life years (OR = 3.69, 95% CI = [1.28, 10.62], p = 0.016). No difference for trading health

Controlling for gender and interactions, respondents were significantly more likely to trade life years for family goals than any other type of goal (OR = 7.39, [2.42, 22.50], p < 0.001). Similar for trading health (OR = 5.11 [1.67, 15.61], p = 0.0042). However, men were 1.55 times more likely to trade life years for

family goals than women (p = 0.0092) and 4.72 times more likely to trade health for family goals than women (p=0.001).

Willingness to trade life years

0.1

1

10

Family Wealth Professional Other

Goal category

Od

ds

rati

o

Male

Female

Willingness to trade health

0.1

1

10

Family Wealth Professional Other

Goal category

Od

ds

Rat

io

Male

Female

ImplicationsImplications

Potential systematic bias in utility assessment, and a caution to those who might seek to interpret preference-based utilities as measures of quality of health.

Patients who are asked to assess their utilities for health states using a time-tradeoff method and who have salient family goals may express greater willingness to trade life years if they are likely to achieve their goals in the years remaining to them than patients with other salient goals.

ImplicationsImplications

As a result, patients with family goals, especially male patients, may generate significantly lower utilities for health states that threaten those goals than patients with other life goals, not because they necessarily consider the quality of those states to be worse, but because their quality of life would suffer so much from being denied their goal.

Alternately, patients won’t want to trade off time to escape a health state that does not threaten a life goal, particularly if the life goal requires time for its achievement. The health state would thereby be overvalued, especially if patients refuse to trade off any time at all.

Now what?Now what?

1. Studies of life goals: create a taxonomy Second study: 100 inpatients at UIC and VA hospitals

2. Develop new utility models that can incorporate goal achievement, multiple goals

3. Develop utility assessment procedures that are goal-sensitive

4. Repeat or simulate decision analyses with goal-sensitive utilities

5. Replicate unwillingness-to-trade studies and ask whether goal differences can explain results

6. Explore implications for societal cost-effectiveness analyses

The Final ThoughtThe Final Thought

People facing medical decisions may – and should – consider not only:

1. How long they might live

2. In what state of health

But also:

3. What they are living for

(and, if we are to measure quality of life correctly)

4. What they would be willing to die (sooner) for.