RT Journal
A1 Hayes S
T1 ADverse outcomes associated with use of proton pump inhibitors and clopidogrel
JF JAMA
JO JAMA
YR 2009
FD July 1
VO 302
IS 1
SP 29
OP 31
DO 10.1001/jama.2009.899
UL http://dx.doi.org/10.1001/jama.2009.899
AB 
One major risk not reported in the baseline characteristics or identified in the article is tobacco use status. It is estimated that 11% of total global cardiac deaths are related to cigarette smoking.2 A significant difference in smoking rates between the cohorts could explain the observed difference in outcomes. Additionally, those individuals who smoke might be more likely to have a PPI prescribed to counter risk factors for peptic ulcer disease in users of clopidogrel and aspirin.