Supplementary Appendix 1a: Scenario Administered to Adjuvant Group
SECTION 1:
1a.
Please read the following statement to the participant and check off the appropriate response:
In the following scenario, you will be asked to provide your opinion. The scenario does not reflect
your current medical situation, and is a general one we are using for many study participants with many
different cancers.
In this hypothetical scenario, you have recently had surgery to remove a cancer and you are now
being offered chemotherapy treatment in order to improve the chances of your cure from the cancer. This is
known as adjuvant chemotherapy. The current standard treatment involves giving everyone two
chemotherapy drugs intravenously (in the veins) for a six hour period, every 2-3 weeks, for a total period of
five months in a day ward setting. The main side effects are tiredness, loss of appetite for a few days after
treatment, and nausea and vomiting (which is usually mild). There is a < 5% chance of severe side effects
such as hospitalization for life threatening infection, or for such things as permanent damage to vital organs
such as kidney, liver, lung, heart, or the nerves (leading to persistent numbness and tingling) with this
therapy. Receiving this treatment would improve the average person’s chances of cure by 5%. For example,
if the average rate of cure was 50%, it would improve to 55% with chemotherapy. Or if the cure rate had
been 20%, it would improve to 25%. This chemotherapy is considered standard treatment and is
recommended to all people who are in this scenario.
Would you want this treatment?
Yes
No
If yes, continue to Section 2. If no, then please continue to Section 1b:
1b.
Please read the following statement to the participant and check off the appropriate response:
What if the average person increases his/her chance of cure by {insert A% here} by receiving
chemotherapy after surgery, compared with surgery alone. Would you want this treatment?
A%
10%
15%
20%
25%
30%
35%
40%
45%
50%
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
If yes to any of the above, continue to Section 2. If no, stop and conclude the interview.
SECTION 2:
2a.
Please read the following statement to the patient:
Recently, researchers have found that 50% of the population carries a genetic sequence that results
in an increase in the cure rate of {2xA}%, when adjuvant chemotherapy is administered to that group of
people. However, the other 50% of people won’t benefit at all from chemotherapy (and so they could suffer
the side effects of the treatment without any increase in their cure rate). If the scenario above applied to
you, would you want to have a blood test performed that could look at your genes to determine which of
these groups you fell into, assuming that this test was offered to you free of charge? A single blood sample
will be drawn and sent to a laboratory for review, and the test will take a day to complete. The
chemotherapy wouldn’t be given until the test results were available which would mean a delay in start of
treatment of approximately 1 day.
If you choose to have the blood test and were found to be in the group that benefit from
chemotherapy you will be offered the chemotherapy treatment. If you had the blood test and were found to
be in the group that did not benefit from chemotherapy you would not receive any treatment.
If you choose not to receive the genetic blood test, then all you know is that the average person
will have A% increase in cure rate, and you would simply receive the chemotherapy.
Would you choose to have the blood test?
Yes
No
If yes, proceed to section 2b. If no, stop and conclude the interview.
2b.
Please read the following statement to the participant. To determine the amount X which
the patient is willing to pay for testing please sequentially present the values listed in the major column.
When the patient reaches an amount when they are no longer willing to pay for testing, please decrease
this amount by the increment values shown in the corresponding row of the minor column until the patient
is again willing to pay for testing. Record the value of this cut off level.
Take the same scenario, except that now the blood test is no longer free. Would you be willing to
be pay {X} for the test?
X Major
X Minor
$0
$400
decrease in increments of $100
$1000
decrease in increments of $100
$2000
decrease in increments of $200
$6000
decrease in increments of $500
$10000
decrease in increments of $1000
Cut-off value $__________
2c.
Please read the statement below to the participant and record the answer on the lines provided:
What do you think is a reasonable price for this test? $__________
SECTION 3:
Please read the statement below to the participant. For question 3a, increase the value Y in
increments of 10% from its baseline of 50% until the patient would no longer opt to pay for testing. When
this level is reached, then decrease this value in increments of 5% until the patient would again opt to pay
for testing. Record this cut off level.
For question 3b, decrease the value Y in increments of 10% from its baseline of 50% until the patient would
no longer opt to pay for testing. When this level is reached, then increase this value in increments of 5%
until the patient would again opt to pay for testing. Record this cut off level.
In the above scenario, half or 50% of the population would benefit from the chemotherapy (group
A), while the other half of the population would not benefit from the chemotherapy (group B) due to
genetic differences between the two groups of people. The blood test would be able to determine which of
the two groups you belonged to and hence whether you would benefit from the chemotherapy or not.
3a) Now, what if instead of 50%, Y% of the people would benefit from chemotherapy, and the rest
wouldn’t. Would you still be interested in paying XC$ for this test?
Cut off level ___%
3b) What if Y% was very low? Would you still be interested in paying XC$ for this test if Y% of
patients would benefit from chemotherapy, and the rest wouldn’t?
Cut off level ___%
SECTION 4:
Please read the statement below to the participant. For the time period Z please sequentially
present the values listed in the major column until the patient would no longer opt to pay for testing. When
that value is reached decrease this amount by the increment values shown in the corresponding row of the
minor column until the patient is again willing to pay for testing. Record the value of this cut off level.
In the above scenario, the blood test took 1 day to complete, leading to a corresponding delay in
starting chemotherapy as the results of the test are needed to make the decision of whether or not to offer
chemotherapy.
Now, what if the blood test took Z amount of time and chemotherapy could not start until after the
results were available. Would you still be willing to pay XC$ to have the test?
Z Major
1 week
2 weeks
4 weeks
8 weeks
Z Minor
decrease in increments of 1 day
decrease in increments of 2 days
decrease in increments of half weeks
decrease in increments of 1 week
Cut-off value ________ weeks ________ days
Supplementary Appendix 1b: Scenario Administered to Metastatic Group
SECTION 1:
1a.
Please read the following statement to the participant and check off the appropriate response:
In the following scenario, you will be asked to provide your opinion. The scenario does not reflect
your current medical situation, and is a general one we are using for many study participants with many
different cancers.
Imagine that you have a cancer that is incurable but is treatable. In this hypothetical scenario, you
are being offered chemotherapy to try and improve the symptoms and complications of your cancer. These
symptoms could include pain, shortness of breath, cough and fatigue. The current standard treatment
involves giving everyone two chemotherapy drugs intravenously (in the veins) for a six hour period, every
2-3 weeks, for a total period of four months in a day ward setting. The main side effects of the
chemotherapy are tiredness, loss of appetite for a few days after treatment, and nausea and vomiting
(usually mild). There is overall a <5% chance of severe side effects such as hospitalization for life
threatening infection, or for such things as permanent damage to vital organs such as kidney, liver, lung,
heart, or the nerves (leading to persistent numbness and tingling) with this therapy.
This chemotherapy would not be curative, but 80% of patients who receive the chemotherapy will
improve for an average of 10 months. Improvement means that the tumour will get smaller or stay stable,
and that you will feel better. This chemotherapy is considered standard treatment and is recommended to all
people who are in this scenario.
Would you want this treatment?
Yes
No
If yes, continue to Section 2. If no, then please continue to Section 1b
Ib.
Please read the following statement to the participant and check off the appropriate response:
Consider the same scenario as Ia, but in this instance consider that instead of 80% of patients benefiting
from chemotherapy, A% of patients would benefit from chemotherapy. Would you now want this
treatment?
A%
85%
90%
95%
100%
Yes
Yes
Yes
Yes
No
No
No
No
If yes, continue to Section 2. If no, then please continue to Section Ic
Ic.
Please read the following statement to the participant and check off the appropriate response:
Consider the same scenario as Ia, but in this case consider that the average person now has a {insert B
here} of severe side effects by taking the chemotherapy? Would you want this treatment?
B%
4%
Yes
No
3%
Yes
No
2%
Yes
No
1%
Yes
No
0%
Yes
No
If yes, continue to Section 2. If no, stop and conclude interview
SECTION 2:
2a.
Please read the following statement to the patient:
Recently, researchers have found that 5% of the population carries a genetic sequence which
makes them unable to tolerate the standard chemotherapy treatment and this group of patients would be
almost guaranteed to be hospitalized due to severe side effects if treated with that chemotherapy. The
remaining 95% of the population can tolerate the chemotherapy without significant problems and the risk
of severe side effects in that group of people would be <1% if treated with the chemotherapy.
If this scenario applied to you, would you want to have a blood test performed that could look at
your genes to determine which of these groups you fell into, assuming this the test was offered to you free
of charge? If you were found to have the genetic abnormality then you would be offered an alternative form
of chemotherapy which would be of equal efficacy and have the usual risk of severe side effects for you
(that is <5%, overall). Blood will be drawn and sent to a laboratory for review, and the test will take a day
to complete. The chemotherapy wouldn’t be given until the test results were available which would mean a
delay in start of treatment by approximately 1 day.
If you choose not to receive the genetic blood test, then all you know is that the average person
will have a <5% risk of severe side effects with the chemotherapy and you would simply receive the
chemotherapy.
Would you choose to have the blood test?
Yes
No
If yes, proceed to section 2b, if no stop and conclude interview.
2b.
Please read the following statement to the participant. To determine the amount X which
the patient is willing to pay for testing please sequentially present the values listed in the major column.
When the patient reaches an amount when they are no longer willing to pay for testing, please decrease
this amount by the increment values shown in the corresponding row of the minor column until the patient
is again willing to pay for testing. Record the value of this cut off level.
Take the same scenario, except that now the blood test is no longer free. Would you be willing to
be pay {X} for the test?
X Major
$0
$400
$1000
$2000
$6000
$10000
X Minor
decrease in increments of $100
decrease in increments of $100
decrease in increments of $200
decrease in increments of $500
decrease in increments of $1000
Cut-off value $ __________
2c.
Please read the statement below to the participant and record the answer on the lines provided:
What do you think is a reasonable price for this test? $ __________
SECTION 3:
3a.
Please read the statement below to the participant. The percentage Y should be sequentially
decreased in increments of 1% from the original value of 5% until the patient would no longer opt to pay
for testing. When that level is reached, the percentage should then be increased in increments of 0.5%, until
the patient is again willing to pay for testing. Record this cut off value.
In the above scenario, 5% of the population would have high risk of severe side effects (group A),
while the other 95% of the population would have a low risk of side effects (group B) due to genetic
differences between the 2 groups of people. The blood test would be able to determine which of the 2 group
you belonged to and hence whether you would tolerate chemotherapy or not.
Now, what if instead of 5%, Y% of the people would be unable to tolerate the chemotherapy due
to severe side effects, and the rest would have a very low risk of side effects. Would you still be interested
in paying XC$ for this test?
Cut-off value __________ %
SECTION 4:
Please read the statement below to the participant. For the time period Z please sequentially
present the values listed in the major column until the patient would no longer opt to pay for testing. When
that value is reached decrease this amount by the increment values shown in the corresponding row of the
minor column until the patient is again willing to pay for testing. Record the value of this cut off level.
In the above scenario, the blood test took 1 day to complete, leading to a corresponding delay in
starting chemotherapy as the results were needed to make the decision of whether or not to offer
chemotherapy.
Now what if the blood test took Z amount of time and chemotherapy could not start until after the
results were available. Would you still be willing to pay XC$ to have the test?
Z Major
1 week
2 weeks
4 weeks
8 weeks
Z Minor
decrease in increments of 1 day
decrease in increments of 2 days
decrease in increments of half weeks
decrease in increments of half weeks
Cut-off value ________ weeks ________ days