@article{ref1,
title="Inappropriate lack of stratification by elective or emergency operation status and missing information on important confounders",
journal="Journal of public health (Oxford)",
year="2006",
author="Lyratzopoulos, Georgios",
volume="28",
number="4",
pages="396-7; author reply 397",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="1741-3842",
doi="10.1093/pubmed/fdl054",
url="http://dx.doi.org/10.1093/pubmed/fdl054"
}