RT Journal
A1 Pan CX, Boal J, et al
T1 HOrmone replacement therapy for secondary prevention of coronary heart disease
JF JAMA
JO JAMA
YR 1999
FD March 3
VO 281
IS 9
SP 794
OP 797
DO 10-1001/pubs.JAMA-ISSN-0098-7484-281-9-jbk0303
UL http://dx.doi.org/10-1001/pubs.JAMA-ISSN-0098-7484-281-9-jbk0303
AB 
Despite the appropriate randomization, blinding, and intention-to-treat
analysis, we are concerned that, during the trial, subjects in the
control and HRT groups were differently exposed to agents that could
affect the primary study outcomes. For example, the authors noted that
more women in the control group began treatment with lipid-lowering
agents (primarily statins) during the trial, and they astutely adjusted
for low-density lipoprotein levels during their analysis. However,
since statin use over an average of 5 years decreases coronary events
and coronary deaths in patients with CHD who have high and normal
cholesterol levels,2- 4 this differential utilization could
still bias the results toward not showing a difference between the 2
groups.