Letters

Technical difficulties may have affected study's results

BMJ 1996; 313 doi: https://doi.org/10.1136/bmj.313.7066.1204 (Published 09 November 1996) Cite this as: BMJ 1996;313:1204

Article usage

Article metrics provide readers and authors with an indication of how often a specific article has been accessed month by month. It counts three formats - abstract/extract, full text and pdf. The page is updated each day.

Usage statistics: July 2003 to February 2018

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AbstractFullPdf
Jul 20030120
Aug 2003070
Sep 20030150
Oct 20030190
Nov 2003190
Dec 20030120
Jan 20042110
Feb 2004060
Mar 20040140
Apr 20040180
May 20040150
Jun 20040110
Jul 2004080
Aug 20049170
Sep 2004040
Oct 2004270
Nov 20042120
Dec 200422260
Jan 2005760
Feb 20054140
Mar 20057110
Apr 2005340
May 2005030
Jun 2005280
Jul 2005230
Aug 2005470
Sep 2005020
Oct 2005430
Nov 200512100
Dec 2005030
Jan 2006260
Feb 2006410
Mar 2006240
Apr 2006070
May 2006120
Jun 2006040
Jul 2006030
Aug 2006010
Oct 2006040
Nov 2006050
Dec 2006020
Jan 2007130
Feb 2007010
Mar 2007030
Apr 2007010
May 2007010
Jun 2007020
Sep 2007120
Nov 2007030
Dec 2007010
Jan 2008010
Feb 2008010
Mar 2008050
Apr 2008120
May 2008010
Jun 2008040
Jul 2008040
Aug 2008030
Sep 2008020
Oct 2008170
Nov 2008470
Jan 2009010
Feb 2009210
Mar 2009100
May 2009100
Aug 2009300
Oct 2009100
Nov 2009200
Dec 2009200
Mar 2010010
May 2010020
Jun 2010010
Jul 2010110
Aug 2010200
Sep 2010530
Oct 2010600
Nov 2010200
Apr 2011020
May 2011200
Aug 2011100
Nov 2011010
Dec 2011020
Jan 2012100
Mar 2012210
May 2012320
Jun 2012220
Jul 2012140
Sep 2012300
Oct 2012010
Nov 2012100
Dec 2012010
Jan 2013020
Feb 2013100
Mar 2013100
Apr 2013200
May 2013110
Jun 2013200
Jul 2013110
Aug 2013100
Oct 2013010
Nov 2013010
Dec 2013100
Feb 2014010
Apr 2014100
Jun 2014400
Jul 2014010
Oct 2014100
Nov 2014010
Mar 2015100
Apr 2015100
Jul 2015100
Aug 20153210
Dec 2015230
Jan 2016100
May 2016300
Jul 2016200
Aug 2016200
Sep 2016400
Oct 2016400
Dec 2016200
Feb 2017500
Mar 2017500
Apr 2017500
May 2017600
Jun 2017400
Jul 2017600
Aug 2017700
Sep 2017500
Oct 2017400
Nov 2017100
Jan 2018200
Feb 2018300
Total2394490