Posted by madeline on November 21, 2006, at 6:40:39
In reply to Depression linked to mortality in heart failure, posted by ed_uk on November 20, 2006, at 15:18:45
I think that you have to be very careful in interpreting any causality from this study.
For instance, the patients with the most severe heart failure (and therefore most likely to die) may be more likely to be depressed. The two variables (death and depression) may occur together, but one doesn't cause the other.
Alternatively, depression may be protective in heart failure. Depressed people may be more LESS likely to die and are therefore over - represented in the study.
Also, the risk ratio is only slightly greater than one, suggesting a very very weak risk.
Sure, this study indicates that we need to monitor cardiac patients carefully for depression, but it simply doesn't show that depression is killing cardiac patients.
poster:madeline
thread:705564
URL: http://www.dr-bob.org/babble/20061117/msgs/705742.html