RT Journal
A1 Sipahi I
T1 LImitations of subgroup analyses in meta-analysis of cardiac resynchronization therapy by qrs duration—reply
JF Archives of Internal Medicine
JO Archives of Internal Medicine
YR 2012
FD February 27
VO 172
IS 4
SP 375
OP 376
DO 10.1001/archinternmed.2011.1685
UL http://dx.doi.org/10.1001/archinternmed.2011.1685
AB 
I disagree with the comments of Magee et al. There was no multiple testing in our meta-analysis. The approach used in this meta-analysis was different from the exploratory subgroup analyses of a single clinical trial. The predefined hypothesis of this meta-analysis was that patients with moderately prolonged QRS interval (ie, 120-150 milliseconds [ms]) do not benefit from cardiac resynchronization therapy (CRT), which was suggested by many investigators even before the major clinical trials of CRT were performed and is biologically plausible.1- 3 Therefore, the only subgroups examined in this analysis were moderately prolonged QRS interval vs severely prolonged QRS interval (ie, >150 ms). Because of this, making corrections for multiple testing does not pertain to this analysis. Moreover, even for a hypothetical situation where multiple testing would be relevant, the significant P value of <.001 for the difference in the response of the 2 QRS subgroups is so robust that the results would not change with any type of correction.