Bio 260, FDA t test
calculations example
Biostatistics practical exercise
Using the t test to determine how long
to conduct clinical trials of novel drug
Bio 260, FDA t test
calculations example
As an example of the practical use of statistics you will take the role of drug
company project managers.
Scenario:
A new drug, ABT007, has been designed by R&D that they think will help
treat Lurgi, a deadly fictional disease that causes skin lesions, intestinal
distress and permanent nerve damage.
About Lurgi:
The primary cause of the deleterious effects is an increase in the number
of b-killer cells in infected individuals.
The disease is transmitted via close bodily contact.
About ABT007:
The drug is administered orally.
The drug acts like a long-term vaccine, it is predicted to reduce the
increase in the number of b-killer cells during infection, thereby
reducing, but not eliminating, the deleterious effects.
Bio 260, FDA t test
calculations example
About marketing ABT007:
The # of b-killer cells in an infected person = 30 per ml
The # of b-killer cells in an un-infected person = 15 per ml
If the drug can be shown to lower the # of b-killer cells in an infected
person it can be sold. I.E., if the p value of a One-tailed,
one-sample t test comparing the value in ABT007 infected
individuals to the normal level for infected indicates significance.
The marketing research department predicts that the net income from
manufacturing the drug will be $2,000,000 per year if the drug
is significant at the p<0.05 level.
The marketing research department predicts that the net income from
manufacturing the drug will be $4,000,000 per year if the drug
is significant at the p<0.01 level.
Drug patents last for 20 years, after that time the drug will no longer
be profitable.
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
$2M per year if p<0.05, $4M per year if p<0.01, Sells for 20 years.
Clinical trial of ABT007:
1,000 individuals at high risk of contracting Lurgi have been recruited
and administered ABT007.
They will be monitored at the end of each year to determine:
How many are infected?
Of those who are infected, what are their # of b-killer cells?
At the end of each year we will do a one-tailed one-sample t test
comparing the values for those infected to the value for
normal infected individuals.
The initial cost to recruit the subjects, pay the subjects and administer
the ABT007 is $5,000,000.
The cost of each year's monitoring and testing is $1,000,000.
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
$2M per year if p<0.05, $4M per year if p<0.01, Sells for 20 years.
Initial cost = $5M, cost each year of trial = $1M.
Clinical trial of ABT007:
The total expected profit from ABT007 will be?
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
The total expected profit from ABT007 will be?
Net income =
20 x $2M, if p<0.05
or
20 x $4M, if p<0.01
Total study cost = initial cost + cost of the years of study
= $5M + (# years of study)($1M)
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 1 begins:
Executives hold a party and wish you all luck since your work is
the future of the company and you are the hope of all people with
Lurgi (and may make profit for the company's shareholders).
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$/yr
sales
$2M
$/yr
sales
$4M
Non-inf
indiv.
1,000
Inf.
indiv.
0
Inf. #
bcells
-
Inf.SD
bcells
-
Inf.SE
bcells
-
tcalc
stat
-
Bio 260, FDA t test
calculations example
Un-infected person = 30 per ml, infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 1 ends:
Executives ask if the study is done yet - they thought you guys would give
quick results.
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$/yr
sales
$2M
$2M
$/yr
sales
$4M
$4M
Non-inf
indiv.
1,000
990
Inf.
indiv.
0
10
SE of infected?
tcalc =?
tcrit = ?
Inf. #
bcells
25.7
Inf.SD
bcells
20.8
Inf.SE
bcells
-
tcalc
stat
-
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$/yr
sales
$2M
$2M
$/yr
sales
$4M
$4M
Non-inf
indiv.
1,000
990
Inf.
indiv.
0
10
Stop study now:
profit = $?
Inf. #
bcells
25.7
tcrit = t0.05,df = t0.05,9 = 1.833
tcrit = t0.01,df = t0.01,9 = 2.821
Inf.SD
bcells
20.8
Inf.SE
tcalc
bcells
stat
6.5775 0.6537
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$/yr
sales
$2M
$2M
$/yr
sales
$4M
$4M
Non-inf
indiv.
1,000
990
Inf.
indiv.
0
10
Stop study now:
profit = -$6M
Inf. #
bcells
25.7
tcrit = t0.05,df = t0.05,9 = 1.833
tcrit = t0.01,df = t0.01,9 = 2.821
Inf.SD
bcells
20.8
Inf.SE
tcalc
bcells
stat
6.5775 0.6537
Continue?
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 2 ends:
Executives ask why the study is still continuing when the year 1
predicted profit numbers were negative.
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$/yr
sales
$2M
$2M
$2M
$/yr
sales
$4M
$4M
$4M
Non-inf
indiv.
1,000
990
981
Inf.
indiv.
0
10
19
SE of infected?
tcalc =?
tcrit = ?
Inf. #
bcells
25.7
25.1
Inf.SD
bcells
20.8
20.5
Inf.SE
tcalc
bcells
stat
6.5775 0.6537
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$/yr
sales
$2M
$2M
$2M
$/yr
sales
$4M
$4M
$4M
Non-inf
indiv.
1,000
990
981
Inf.
indiv.
0
10
19
Stop study now:
profit = $?
Inf. #
bcells
25.7
25.1
tcrit = t0.05,df = t0.05,18 = 1.734
tcrit = t0.01,df = t0.01,18 = 2.552
Inf.SD
bcells
20.8
20.5
Inf.SE
tcalc
bcells
stat
6.5775 0.6537
4.7030 1.0419
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$/yr
sales
$2M
$2M
$2M
$/yr
sales
$4M
$4M
$4M
Non-inf
indiv.
1,000
990
981
Inf.
indiv.
0
10
19
Stop study now:
profit = -$7M
Inf. #
bcells
25.7
25.1
tcrit = t0.05,df = t0.05,18 = 1.734
tcrit = t0.01,df = t0.01,18 = 2.552
Inf.SD
bcells
20.8
20.5
Inf.SE
tcalc
bcells
stat
6.5775 0.6537
4.7030 1.0419
Continue?
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $4M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 3 ends:
Executives ask why the study is still continuing when the year 2
predicted profit numbers were lower than year 1 previous ones
NEWS: Rates of Lurgi infection are down due to public health efforts.
- Marketing department predicts that the market is now 50% smaller.
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$/yr
sales
$2M
$2M
$2M
$1M
$/yr
sales
$4M
$4M
$4M
$2M
Non-inf
indiv.
1,000
990
981
967
Inf.
indiv.
0
10
19
33
SE of infected?
tcalc =?
tcrit = ?
Inf. #
bcells
25.7
25.1
24.7
Inf.SD
bcells
20.8
20.5
20.8
Inf.SE
tcalc
bcells
stat
6.5775 0.6537
4.7030 1.0419
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$/yr
sales
$2M
$2M
$2M
$1M
$/yr
sales
$4M
$4M
$4M
$2M
Non-inf
indiv.
1,000
990
981
967
Inf.
indiv.
0
10
19
33
Stop study now:
profit = $?
Inf. #
bcells
25.7
25.1
24.7
tcrit = t0.05,df = t0.05,30 = 1.697
tcrit = t0.01,df = t0.01,30 = 2.457
Inf.SD
bcells
20.8
20.5
20.8
Inf.SE
tcalc
bcells
stat
6.5775 0.6537
4.7030 1.0419
3.6208 1.4638
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$/yr
sales
$2M
$2M
$2M
$1M
$/yr
sales
$4M
$4M
$4M
$2M
Non-inf
indiv.
1,000
990
981
967
Inf.
indiv.
0
10
19
33
Stop study now:
profit = -$8M
Inf. #
bcells
25.7
25.1
24.7
tcrit = t0.05,df = t0.05,30 = 1.697
tcrit = t0.01,df = t0.01,30 = 2.457
Inf.SD
bcells
20.8
20.5
20.8
Inf.SE
tcalc
bcells
stat
6.5775 0.6537
4.7030 1.0419
3.6208 1.4638
Continue?
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 4 ends:
Executives ask why the study is still continuing when the year 3
predicted profit numbers were lower than year 2 previous ones
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
Non-inf
indiv.
1,000
990
981
967
955
Inf.
indiv.
0
10
19
33
45
SE of infected?
tcalc =?
tcrit = ?
Inf. #
bcells
25.7
25.1
24.7
25.1
Inf.SD
bcells
20.8
20.5
20.8
20.4
Inf.SE
tcalc
bcells
stat
6.5775 0.6537
4.7030 1.0419
3.6208 1.4638
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
Non-inf
indiv.
1,000
990
981
967
955
Inf.
indiv.
0
10
19
33
45
Stop study now:
profit = $?
Inf. #
bcells
25.7
25.1
24.7
25.1
tcrit = t0.05,df = t0.05,40 = 1.684
tcrit = t0.01,df = t0.01,40 = 2.423
Inf.SD
bcells
20.8
20.5
20.8
20.4
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
tcalc
stat
0.6537
1.0419
1.4638
1.6113
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
Non-inf
indiv.
1,000
990
981
967
955
Inf.
indiv.
0
10
19
33
45
Stop study now:
profit = -$9M
Inf. #
bcells
25.7
25.1
24.7
25.1
tcrit = t0.05,df = t0.05,40 = 1.684
tcrit = t0.01,df = t0.01,40 = 2.423
Inf.SD
bcells
20.8
20.5
20.8
20.4
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
Continue?
tcalc
stat
0.6537
1.0419
1.4638
1.6113
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 5 ends:
Executives ask why the study is still continuing when the year 4
predicted profit numbers were lower than year 3 previous ones
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
Non-inf
indiv.
1,000
990
981
967
955
943
Inf.
indiv.
0
10
19
33
45
57
SE of infected?
tcalc =?
tcrit = ?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
tcalc
stat
0.6537
1.0419
1.4638
1.6113
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
Non-inf
indiv.
1,000
990
981
967
955
943
Inf.
indiv.
0
10
19
33
45
57
Stop study now:
profit = $?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
tcrit = t0.05,df = t0.05,50 = 1.676
tcrit = t0.01,df = t0.01,50 = 2.403
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
Non-inf
indiv.
1,000
990
981
967
955
943
Inf.
indiv.
0
10
19
33
45
57
Stop study now:
profit = -$10M
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
tcrit = t0.05,df = t0.05,50 = 1.676
tcrit = t0.01,df = t0.01,50 = 2.403
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
Continue?
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $2M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 6 ends:
Executives ask why the study is still continuing when the
drug has not been shown to be effective.
NEWS: a competitor has just received FDA approval for a drug that
"cures" Lurgi.
- If administered quickly the drug reverses all deleterious effects.
- Marketing department predicts that by using appropriate advertising
ABT007 can still be marketed, although fully informed
doctors will not prescribe it so the market is 50% smaller.
- Administering to study subjects invalidates their data.
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
Inf.
indiv.
0
10
19
33
45
57
69
SE of infected?
tcalc =?
tcrit = ?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
Inf.
indiv.
0
10
19
33
45
57
69
Stop study now:
profit = $?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
tcrit = t0.05,df = t0.05,60 = 1.671
tcrit = t0.01,df = t0.01,60 = 2.390
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
Inf.
indiv.
0
10
19
33
45
57
69
Stop study now:
profit = -$1M
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
tcrit = t0.05,df = t0.05,60 = 1.671
tcrit = t0.01,df = t0.01,60 = 2.390
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
Continue?
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 7 ends:
Executives send congratulations that the year 6 predicted profit numbers
were better than the year 5 previous ones, but would prefer positive values.
NEWS: a new internal bonus system will allow each employee to
collect a share of their division's profits.
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
Inf.
indiv.
0
10
19
33
45
57
69
79
SE of infected?
tcalc =?
tcrit = ?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
Inf.
indiv.
0
10
19
33
45
57
69
79
Stop study now:
profit = $?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
tcrit = t0.05,df = t0.05,60 = 1.671
tcrit = t0.01,df = t0.01,60 = 2.390
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
No bonuses
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
Inf.
indiv.
0
10
19
33
45
57
69
79
Stop study now:
profit = -$2M
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
tcrit = t0.05,df = t0.05,60 = 1.671
tcrit = t0.01,df = t0.01,60 = 2.390
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
Continue?
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 8 ends:
Executives ask why the study is still continuing when the
drug has been show to work and the year 7 predicted profit
numbers were lower than year 6 previous ones
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$13M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
913
Inf.
indiv.
0
10
19
33
45
57
69
79
87
SE of infected?
tcalc =?
tcrit = ?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
24.7
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
20.2
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$13M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
913
Inf.
indiv.
0
10
19
33
45
57
69
79
87
Stop study now:
profit = $?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
24.7
tcrit = t0.05,df = t0.05,80 = 1.664
tcrit = t0.01,df = t0.01,80 = 2.374
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
20.2
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
2.1657
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
2.4473
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$13M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$0.5M
Bonuses
$14,000 each
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
913
Inf.
indiv.
0
10
19
33
45
57
69
79
87
Stop study now:
profit = $7M
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
24.7
tcrit = t0.05,df = t0.05,80 = 1.664
tcrit = t0.01,df = t0.01,80 = 2.374
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
20.2
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
2.1657
Continue?
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
2.4473
Bio 260, FDA t test
calculations example
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year 9 ends:
Executives ask why the study continued, the drug could not have been more
profitable than after year 8.
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$13M
$14M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$0.5M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
913
902
Inf.
indiv.
0
10
19
33
45
57
69
79
87
98
SE of infected?
tcalc =?
tcrit = ?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
24.7
24.6
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
20.2
20.3
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
2.1657
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
2.4473
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$13M
$14M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$0.5M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
913
902
Inf.
indiv.
0
10
19
33
45
57
69
79
87
98
Stop study now:
profit = $?
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
24.7
24.6
tcrit = t0.05,df = t0.05,80 = 1.664
tcrit = t0.01,df = t0.01,80 = 2.374
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
20.2
20.3
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
2.1657
2.0506
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
2.4473
2.6334
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$13M
$14M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$0.5M
$0.5M
Bonuses
$12,000 each
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
913
902
Inf.
indiv.
0
10
19
33
45
57
69
79
87
98
Stop study now:
profit = $6M
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
24.7
24.6
tcrit = t0.05,df = t0.05,80 = 1.664
tcrit = t0.01,df = t0.01,80 = 2.374
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
20.2
20.3
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
2.1657
2.0506
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
2.4473
2.6334
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$13M
$14M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$0.5M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
913
902
Inf.
indiv.
0
10
19
33
45
57
69
79
87
98
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
24.7
24.6
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
20.2
20.3
OBSERVE: the SE decreases as sample size increases
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
2.1657
2.0506
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
2.4473
2.6334
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$13M
$14M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$0.5M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
913
902
Inf.
indiv.
0
10
19
33
45
57
69
79
87
98
Inf. #
bcells
25.7
25.1
24.7
25.1
25.4
24.9
24.8
24.7
24.6
Inf.SD
bcells
20.8
20.5
20.8
20.4
20.8
20.5
20.3
20.2
20.3
OBSERVE: the tcalc statistic increases even though the
difference in means stays the same, because SE decreases
Inf.SE
bcells
6.5775
4.7030
3.6208
3.0411
2.7550
2.4679
2.2839
2.1657
2.0506
tcalc
stat
0.6537
1.0419
1.4638
1.6113
1.6697
2.0665
2.2768
2.4473
2.6334
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
tcrit = t0.05,df = t0.05,9 = 1.833
tcrit = t0.01,df = t0.01,9 = 2.821
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Study
year
0
1
2
3
4
5
6
7
8
9
$
spent
$5M
$6M
$7M
$8M
$9M
$10M
$11M
$12M
$13M
$14M
$/yr
sales
$2M
$2M
$2M
$1M
$1M
$1M
$0.5M
$0.5M
$0.5M
$0.5M
$/yr
sales
$4M
$4M
$4M
$2M
$2M
$2M
$1M
$1M
$1M
$1M
Non-inf
indiv.
1,000
990
981
967
955
943
931
921
913
902
Inf.
indiv.
0
10
19
33
45
57
69
79
87
98
tcrit = t0.05,df = t0.05,18 = 1.734
tcrit = t0.01,df = t0.01,18 = 2.552
tcrit = t0.05,df = t0.05,30 = 1.697
tcrit = t0.01,df = t0.01,30 = 2.457
tcrit = t0.05,df = t0.05,40 = 1.684
tcrit = t0.01,df = t0.01,40 = 2.423
tcrit = t0.05,df = t0.05,50 = 1.676
tcrit = t0.01,df = t0.01,50 = 2.403
tcrit = t0.05,df = t0.05,60 = 1.671
tcrit = t0.01,df = t0.01,60 = 2.390
tcrit = t0.05,df = t0.05,80 = 1.664
tcrit = t0.01,df = t0.01,80 = 2.374
OBSERVE: the tcrit statistic decreases as sample size increases
Infected person = 30 per ml, un-infected person = 15 per ml
Profit = 20 x $0.5M - $5M - (# years of study)($1M), if p<0.05
Profit = 20 x $1M - $5M - (# years of study)($1M), if p<0.01
Bio 260, FDA t test
calculations example
Clinical trial of ABT007:
Task of your division is to monitor the trial and
decide when it will end in order to maximize profit.
Year
ended
0
1
2
3
4
5
6
7
8
9
$
profit
-$6M
-$7M
-$8M
-$9M
-$10M
-$1M
-$2M
+$7M
+$6M
0
10
19
33
45
57
69
79
87
98
Competitor cure here
Didn't treat 10 people
Didn't treat 8 people
Didn't treat 9 people
NOTE: did anyone suggest treating these people with the competitor's cure?
- Does the company have an ethical responsibility to give cure to these people?
- Did YOU have an ethical responsibility to give drug to these people?
Tuskegee experiment
1932:
399 syphilis infected men start study
200 non-syphilis controls
1947:
Penicillian discovered to cure syphilis
Study subjects were not given penicillin
Study subjects were prevented from receiving penicillin.
Local clinics were instructed to deny treatment & 250 draftees
were prevented from receiving cure.
1972:
"Study" finally ended
28 of the 399 died from syphilis
100 of 399 died from complications related to syphilis
40 wives infected
19 children born with syphilis related birth defects
Who did these evil acts?
Institutions involved in Tuskegee study:
Tuskegee Institute: an Alabama HBC (Historically Black College)
US PHS (Public Health Service)
CDC (Centers for Disease Control)
NMA (national Medical Association)
Mission statement: "To advance the art and science of medicine for people of
African descent through education, advocacy, and health policy to promote
health and wellness, eliminate health disparities, and sustain physician viability.
AMA (American medical association)
Long-term impact:
1974: regulations on true informed consent started
1997: Presidential apology
1990: Survey of 1056 African-Americans in South
34% AIDS is artificial
35% AIDS is a form of genocide
44% Government not "telling truth" about AIDS
Q: Why would people do this sort of thing?
Not racism: Eunice Evers did
much of the patient monitoring
and contact. (Only staff person
to do all 40 years)
A: because people tell them to
Milgram experiment, 1963+
E: "Experimenter" - person running the study.
T: "Teacher" asks Learner questions.
L: "Learner" must answer questions.
Learner must memorize word pairs
Teacher then asks for partner word
- Correct - next Q
- Incorrect - Experimenter asks Teacher to
administer electric shock
Shocks increase by 15 volts per wrong answer
What do the Teachers and Learners do?
A: because people tell them to
Milgram experiment, 1963+
E: "Experimenter" - person running the study.
T: "Teacher" asks Learner questions.
L: "Learner" must answer questions.
What do the Teachers and learners do?
This is really an experiment
on the Teachers
In fact the Learner is an actor, shocks are
not real, but seem real to Teacher. First the
Learner screams in pain, then bangs on wall asking to stop, then complains
about heart condition, then becomes silent (I.E., dead or unconscious).
If the Teacher asks to stop, the experimenter provides 4 verbal prompts to
continue, after the 4th prompt the experiment stops.
A: because people tell them to
Milgram experiment, 1963+
E: "Experimenter" - person running the study.
T: "Teacher" asks Learner questions.
L: "Learner" must answer questions.
What do the Teachers and Learners do?
Results (n=40)
- Some paused at 135V and expressed concern.
- Only 1 person stopped before 300V.
- 26/40 Teachers went all the way to 450V and silence.
- Nobody who stopped early insisted overall experiment should end.
- Nobody left room to check on Learner without asking permission first.
Multiple similar studies agree that ~65% of Teachers can be easily
convinced to inflict what they believe to be painful (AND LETHAL!) shocks.
If there are more accomplices Teachers 92% become killers.
A: because people tell them to
Milgram experiment, 1963+
E: "Experimenter" - person running the study.
T: "Teacher" asks Learner questions.
L: "Learner" must answer questions.
Implications?
Normal people can be convinced to kill merely
by being told to by perceived authority figures
and that this power is enhanced in groups.
Explains (but may or may not excuse) the unethical behavior by Nazi and
Abu Ghraib guards under orders from superiors.
We "scientists" must be careful in scientific situations because we are the
"experts" and are authority figures, we must be careful of the power we
have even if we don't realize it.