Statistics Case Study
This is the first in a series of case studies I'm creating to help scientists learn the fine points of data analysis.
One consequence of heart failure is that the heart gets larger (cardiomegaly). This is a physiological adaptation to allow the heart to pump enough blood to perfuse the organs. Eventually the heart grows so large it is not able to pump blood efficiently. Therefore it makes sense to seek a drug that would reduce cardiomegaly in heart failure.
This study tested such a drug in an animal model of heart failure. Half the rats were given the surgery to create heart failure, and half were given sham surgery. In each of those groups, half of the rats were injected with an experimental drug and half were injected with vehicle as a control. (The data are real, but the investigators prefer to remain anonymous).

|
|
Sham surgery |
CHF |
||||
|
|
Mean |
SD |
n |
Mean |
SD |
n |
|
Vehicle |
0.3124 |
0.0211 |
10 |
0.5481 |
0.0723 |
9 |
|
Drug |
0.3518 |
0.0251 |
10 |
0.4669 |
0.0768 |
10 |
Is the drug effective in blunting the increase in heart weight?
Think about how you would analyze the data before reading the case-study. Better, download the raw data and do your own analyses.
When you have thought about how you would analyze the data, read this 15 page case-study. Here is the corresponding Prism file. Please email me with your suggestions about this case study, or ideas for future case studies.
Saturday, January 16, 2010 at 8:20AM
2 Comments 
Reader Comments (2)
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