PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
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Appendix – Electronic Supplemental Materials (ESM)
Hypothetical Scenarios Questionnaire. Couples received one of three versions of the
hypothetical scenario questionnaire in order to test hypotheses about the impact of positive versus
negative framing, high versus low amounts of information, and the use of images on preferences for
end of life medical treatments. The versions differed in the following four ways. 1) Form 1 and Form
3 framed the chance of success from CPR positively, in terms of chance of survival for all CPR items
(i.e., “90% chance of surviving after receiving treatment”), whereas Form 2 framed the chance of
success from CPR negatively, in terms of chance of dying (i.e., “10% chance of dying after receiving
treatment”) for all CPR items. 2) Form 1 and Form 3 included high levels of information for all
mechanical ventilation items (e.g., “tube inserted down your throat”) and mentioned the treatment
name (“mechanical ventilation”) multiple times, whereas Form 2 included little information on the
procedure and mentioned the name once for the mechanical ventilation items. 3) Form 1 and Form 3
included information on length of hospital stay for all intravenous antibiotics items, whereas Form 2
did not include this information within intravenous antibiotics items. 4) Form 1 and Form 2 did not
contain any photos or images of treatment options, whereas Form 3 contained photos or images of each
of the four treatment items (CPR, mechanical ventilation, artificial nutrition, and intravenous
antibiotics) next to the item. Thus Form 1 and Form 3 differed only on the presence of images.
In order to test for potential effects from positive or negative framing, high or low levels of
information, and presence or absence of images, independent samples t-tests were run comparing the
means for all treatment options across the three forms (see ESM Table 1). Only one significant
difference was found between forms on the treatment preferences, on the artificial nutrition items,
where couples who completed Form 3 (with an image) indicated greater interest in receiving this
intervention than couples who completed Form 1 (without the image of artificial nutrition). Given the
PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
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general lack of significant differences between forms, all couples/forms were combined in further
analyses. Below is Form 3 which includes images.
PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
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Hypothetical Scenario Questionnaire - Form 3
The following questions ask about your treatment preferences in different medical situations. Please
read through each scenario and the treatment options for that scenario. Then, indicate your preference
for the treatment on the 5-point scale.
1. You are in your current health (the way you are feeling now):
a.
If your breathing or heartbeat stops, medical personnel would
administer cardiopulmonary resuscitation, or CPR, which is the use of drugs
and electric shock to start the heart beating and artificial breathing. Imagine
that you have approximately a 90% chance of surviving after receiving CPR
and leaving the hospital. Please indicate whether or not you would want this
treatment by circling your response from 1 to 5:
CPR
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
b.
If your breathing became difficult, medical personnel would
administer mechanical ventilation, which is breathing by machine.
In mechanical ventilation, a tube would be inserted down your throat
to your windpipe and connected to the machine. Please indicate
whether or not you would want mechanical ventilation by circling
your response from 1 to 5:
Mechanical Ventilation
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
c.
If you became unable to eat, artificial nutrition, which is
nutrition and fluid given through a tube in the veins, nose, or
stomach, would be administered. Please indicate whether or not
you would want this treatment by circling your response from 1 to
5:
Artificial Nutrition
PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
1
definitely yes
2
probably yes
3
not sure
4
probably no
4
5
definitely no
d.
If you developed a condition like pneumonia, intravenous
antibiotics, which are antibiotics administered through a tube in a vein in a
hospital, would be administered. You would be required to stay in the
hospital for some length of time. Please indicate whether or not you
would want this treatment by circling your response from 1 to 5:
IV Antibiotics
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
__________________________________________________________________________________
2. Imagine that you have trouble remembering things and thinking clearly. You cannot always
recognize people you know. You have no chance of recovery. Your mental abilities may get worse
quickly or you may stay the way you are now for a long time. Your physical condition and abilities
are unaffected.
a.
If your breathing or heartbeat stops, medical personnel would
administer cardiopulmonary resuscitation, or CPR, which is the use of drugs
and electric shock to start the heart beating and artificial breathing. Imagine
that you have approximately a 30% chance of surviving after receiving CPR
and leaving the hospital. Please indicate whether or not you would want this
treatment by circling your response from 1 to 5:
CPR
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
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b.
If your breathing became difficult, medical personnel would
administer mechanical ventilation, which is breathing by machine.
In mechanical ventilation, a tube would be inserted down your throat
to your windpipe and connected to the machine. Please indicate
whether or not you would want mechanical ventilation by circling
your response from 1 to 5:
Mechanical Ventilation
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
c.
If you became unable to eat, artificial nutrition, which is
nutrition and fluid given through a tube in the veins, nose, or
stomach, would be administered. Please indicate whether or not
you would want this treatment by circling your response from 1 to
5:
Artificial Nutrition
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
d.
If you developed a condition like pneumonia, intravenous
antibiotics, which are antibiotics administered through a tube in a vein in a
hospital, would be administered. You would be required to stay in the
hospital for some length of time. Please indicate whether or not you
would want this treatment by circling your response from 1 to 5:
IV Antibiotics
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
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__________________________________________________________________________________
3. Imagine that you have suffered a severe stroke and have been in a coma for six weeks. In the
opinion of your doctor, you have a 20% chance of regaining awareness and the ability to think, reason,
and remember. If you do not recover, your physical condition will slowly decline over time. You rely
on others for help with feeding, bathing, dressing, and toileting. You may live in this condition for
several years.
a.
If your breathing or heartbeat stops, medical personnel would
administer cardiopulmonary resuscitation, or CPR, which is the use of drugs
and electric shock to start the heart beating and artificial breathing. Imagine
that you have approximately a 10% chance of surviving after receiving
CPR and leaving the hospital. Please indicate whether or not you would
want this treatment by circling your response from 1 to 5:
CPR
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
b.
If your breathing became difficult, medical personnel would
administer mechanical ventilation, which is breathing by machine.
In mechanical ventilation, a tube would be inserted down your throat
to your windpipe and connected to the machine. Please indicate
whether or not you would want mechanical ventilation by circling
your response from 1 to 5:
Mechanical Ventilation
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
c.
If you developed a condition like pneumonia, intravenous
antibiotics, which are antibiotics administered through a tube in a vein in a
hospital, would be administered. You would be required to stay in the
hospital for some length of time. Please indicate whether or not you
would want this treatment by circling your response from 1 to 5:
IV Antibiotics
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1
definitely yes
2
probably yes
3
not sure
4
probably no
7
5
definitely no
__________________________________________________________________________________
4. Imagine that, as the result of an accident, you were able to talk and understand what was going on
but needed someone to dress, bath, feed, and move you. In your doctor’s opinion you have no chance
of recovery.
a.
If your breathing or heartbeat stops, medical personnel would
administer cardiopulmonary resuscitation, or CPR, which is the use of drugs
and electric shock to start the heart beating and artificial breathing. Imagine
that you have approximately a 40% chance of surviving after receiving
CPR and leaving the hospital. Please indicate whether or not you would
want this treatment by circling your response from 1 to 5:
CPR
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
b.
If your breathing became difficult, medical personnel would
administer mechanical ventilation, which is breathing by machine.
In mechanical ventilation, a tube would be inserted down your throat
to your windpipe and connected to the machine. Please indicate
whether or not you would want mechanical ventilation by circling
your response from 1 to 5:
Mechanical Ventilation
1
definitely yes
2
probably yes
3
not sure
c.
If you became unable to eat, artificial nutrition, which is
nutrition and fluid given through a tube in the veins, nose, or
stomach, would be administered. Please indicate whether or not
you would want this treatment by circling your response from 1 to
5:
4
probably no
5
definitely no
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Artificial Nutrition
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
d.
If you developed a condition like pneumonia, intravenous
antibiotics, which are antibiotics administered through a tube in a vein in a
hospital, would be administered. You would be required to stay in the
hospital for some length of time. Please indicate whether or not you
would want this treatment by circling your response from 1 to 5:
IV Antibiotics
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
5. Imagine that you have cancer, which has spread to more than one part of your body. You are tired
and weak, requiring some help with household chores. Your thinking and memory are unaffected.
You are not in pain. In the opinion of your doctor, you have no chance of recovery. Your doctor
estimates that you have about six months to live.
a.
If your breathing or heartbeat stops, medical personnel would
administer cardiopulmonary resuscitation, or CPR, which is the use of drugs
and electric shock to start the heart beating and artificial breathing. Imagine
that you have approximately a 10% chance of surviving after receiving
CPR and leaving the hospital. Please indicate whether or not you would
want this treatment by circling your response from 1 to 5:
CPR
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
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b.
If your breathing became difficult, medical personnel would
administer mechanical ventilation, which is breathing by machine.
In mechanical ventilation, a tube would be inserted down your throat
to your windpipe and connected to the machine. Please indicate
whether or not you would want mechanical ventilation by circling
your response from 1 to 5:
Mechanical Ventilation
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
c.
If you became unable to eat, artificial nutrition, which is
nutrition and fluid given through a tube in the veins, nose, or
stomach, would be administered. Please indicate whether or not
you would want this treatment by circling your response from 1 to
5:
Artificial Nutrition
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
d.
If you developed a condition like pneumonia, intravenous
antibiotics, which are antibiotics administered through a tube in a vein in a
hospital, would be administered. You would be required to stay in the
hospital for some length of time. Please indicate whether or not you
would want this treatment by circling your response from 1 to 5:
IV Antibiotics
1
definitely yes
2
probably yes
3
not sure
4
probably no
5
definitely no
PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
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ESM Table 1
Scenario and treatment means across forms
Form 1
Form 2
Form 3
Current Health
1.68
1.73
1.53a
Cognitive Impairment
2.88
2.73
2.71
Severe Stroke
3.57
3.53
3.49
Physical Impairment
2.90
2.93
2.81
Cancer
3.05
3.01
2.96
CPR
2.60
2.63
2.51
Mechanical Ventilation
2.96
2.90
2.91
Artificial Nutrition
2.95
2.91
2.68b
IV Antibiotics
2.61
2.56
2.53
Hypothetical Scenario
Treatment
Note. Mean differences tested using independent samples t test. a indicates significant difference
between form 3 and form 1 & 2, p < .05. b indicates significant difference between form 3 and form 1,
p < .05. Form 3 included images of the various treatment options.
PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
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ESM Table 2
Moderated regression analyses predicting self-ratings of average treatment preferences from proxyratings of average treatment preference and proxy-characteristics
Criterion: Average wife self-rating
Husband
Characteristic
Beta
Average
Husband
Proxy-Rating
Beta
-.193**
-.076
.341**
Interaction
Term (husband
characteristic X
husband proxyrating)
Beta
-.083
-.263
-.205**
-.198**
-.159*
-.191**
-.195**
-.162*
-.150*
.189
.071
.046
.078
.029
.054
.073
.050
.396*
.346**
.333**
.344**
.342**
.304**
.371**
.390**
.078
-.049
.027
-.075
-.053
-.168*
-.033
.068
Husband
Age
Husband
Characteristic
Marital Satisfaction
Caregiving
Experience1
Time Dated
Religiosity
Spirituality
Moral Strictness
Conservativeness
Agreeableness
Conscientiousness
Model R
square
.205
.157
.208
.198
.183
.197
.229
.201
.205
Criterion: Average husband self-rating
Wife Age
Wife
Characteristic
Beta
Average
Wife ProxyRating
Beta
Interaction
Term (wife
characteristic X
wife proxyrating)
Beta
.049
Model R
square
Wife Characteristic
Marital Satisfaction
-.100
.173**
.417**
.246
Caregiving
Experience2
-.226
.293*
.353**
.145
.316
Time Dated
-.120
-.061
.482**
.018
.214
Religiosity
-.110
.021
.415**
-.023
.218
Spirituality
-.118
-.065
.408**
.068
.232
Moral Strictness
-.114
-.027
.415**
.071
.222
Conservativeness
-.109
-.063
.413**
-.032
.222
Agreeableness
-.110
-.019
.407**
.021
.210
Conscientiousness
-.112
.012
.411**
.063
.210
1
2
Note. n = 197; indicates n = 36 husbands who had caregiving experience, indicates n = 46 wives
who had caregiving experience. * indicates Beta coefficient significant at p < .05, ** indicates Beta
coefficient significant at p < .01
PROXIES IN END-OF-LIFE DECISIONS, SUPPLEMENTAL MATERIALS
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ESM Table 3
Moderated regression analyses predicting self-ratings of average treatment preferences from proxyratings of average treatment preference and proxy-self similarity
Criterion: Average wife self-rating
Husband
Age Beta
Variable
Marital
Satisfaction
Religiosity
Spirituality
Moral Strictness
Conservativeness
Agreeableness
Conscientiousness
-.196**
-.197**
-.154*
-.191**
-.192**
-.012*
-.147*
Husband
Variable
Beta
Wife
Variable
Beta
-.118
.029
.018
.021
.042
.078
.129
.057
.048
.022
-.002
.049
-.057
.011
Average
Husband
ProxyRating
Beta
.340**
.341**
.346**
.346**
.347**
.371**
.371**
Absolute
Difference
Score Beta
.046
-.060
.113
.025
.007
-.063
.059
Model R
square
.200
.200
.189
.196
.199
.200
.199
Criterion: Average husband self-rating
Variable
Marital
Satisfaction
Religiosity
Spirituality
Moral Strictness
Conservativeness
Agreeableness
Conscientiousness
Wife Age
Beta
Wife
Variable
Beta
Husband
Variable
Beta
Average
Wife
ProxyRating
Beta
Absolute
Difference
Score
Beta
Model R
square
-.110
-.131
-.094
-.104
-.108
-.123
-.127
.106
-.051
-.098
-.017
-.061
-.025
.014
.209*
.136
-.021
.113
.064
.170*
.021
.466**
.440**
.455**
.466**
.464**
.427**
.431**
.018
-.010
-.142*
-.130*
-.170*
-.026
.049
.244
.233
.218
.234
.243
.217
.189