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Research

Written informed consent and selection bias in observational studies using medical records: systematic review

BMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b866 (Published 12 March 2009) Cite this as: BMJ 2009;338:b866

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: March 2009 to February 2020

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AbstractFullPdf
Mar 20091650314551
Apr 2009262397455
May 200963126122
Jun 2009407660
Jul 2009547974
Aug 2009216957
Sep 2009265844
Oct 2009316755
Nov 2009295850
Dec 2009243424
Jan 2010295841
Feb 2010413430
Mar 2010574032
Apr 2010484530
May 2010647538
Jun 2010384623
Jul 2010236135
Aug 2010264025
Sep 2010394729
Oct 2010376321
Nov 2010205822
Dec 2010513931
Jan 2011734737
Feb 2011465632
Mar 2011306631
Apr 2011152725
May 2011263331
Jun 2011281215
Jul 201182920
Aug 2011132311
Sep 201115198
Oct 2011154317
Nov 2011115418
Dec 20110515
Jan 201206415
Feb 201206318
Mar 201205815
Apr 201205710
May 2012231276
Jun 201276211
Jul 201236515
Aug 2012310312
Sep 20122988
Oct 20121489
Nov 2012011716
Dec 20120507
Jan 20130886
Feb 20131555
Mar 20130849
Apr 20132946
May 2013013019
Jun 2013010215
Jul 2013112019
Aug 2013112323
Sep 2013011015
Oct 201311458
Nov 2013111717
Dec 2013312212
Jan 2014010811
Feb 2014016728
Mar 2014013811
Apr 2014014715
May 2014015824
Jun 2014011117
Jul 201406918
Aug 201404910
Sep 201408721
Oct 20140319
Nov 20140342
Dec 201406523
Jan 201506420
Feb 2015012262
Mar 2015215447
Apr 2015317238
May 2015015049
Jun 20153929
Jul 201507832
Aug 20151759
Sep 201518120
Oct 201546416
Nov 2015113222
Dec 2015614114
Jan 2016510714
Feb 2016213016
Mar 2016013423
Apr 2016111215
May 2016216624
Jun 201609921
Jul 2016011613
Aug 2016110121
Sep 201609923
Oct 2016211431
Nov 2016112919
Dec 201618823
Jan 2017110814
Feb 2017012521
Mar 2017013517
Apr 2017111812
May 2017015022
Jun 201708815
Jul 201709613
Aug 2017010010
Sep 2017010715
Oct 2017014012
Nov 2017012414
Dec 2017012413
Jan 2018014822
Feb 2018012413
Mar 2018211819
Apr 2018014630
May 2018216530
Jun 201809228
Jul 201808115
Aug 2018010817
Sep 2018012922
Oct 2018013113
Nov 2018014122
Dec 2018010916
Jan 2019110118
Feb 2019014831
Mar 2019023521
Apr 2019226430
May 2019320418
Jun 2019014531
Jul 2019124721
Aug 2019238919
Sep 2019233310
Oct 2019543937
Nov 2019433437
Dec 2019316218
Jan 2020412919
Feb 2020111012
Total3072145773912