Intended for healthcare professionals

Education And Debate

Why we need observational studies to evaluate the effectiveness of health care

BMJ 1996; 312 doi: https://doi.org/10.1136/bmj.312.7040.1215 (Published 11 May 1996) Cite this as: BMJ 1996;312:1215

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 July 2019

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AbstractFullPdf
Jul 200301160
Aug 20030970
Sep 200311690
Oct 200332080
Nov 200302180
Dec 200301280
Jan 200401890
Feb 200402490
Mar 200412280
Apr 200432720
May 200432240
Jun 200402380
Jul 200432490
Aug 200412560
Sep 2004152590
Oct 2004132570
Nov 2004223160
Dec 2004282690
Jan 2005282990
Feb 2005183040
Mar 200572690
Apr 2005374520
May 2005302640
Jun 2005222520
Jul 2005414050
Aug 2005232730
Sep 2005233110
Oct 2005334110
Nov 2005224120
Dec 2005192940
Jan 2006232880
Feb 2006253630
Mar 2006264410
Apr 20061193450
May 20062182320
Jun 20061921730
Jul 20061591790
Aug 20061001950
Sep 2006352220
Oct 2006233380
Nov 2006292740
Dec 2006111330
Jan 2007261570
Feb 2007241861
Mar 2007262280
Apr 2007312450
May 2007251770
Jun 2007221320
Jul 2007271381
Aug 2007231580
Sep 2007121400
Oct 2007403440
Nov 2007432820
Dec 2007281610
Jan 2008522060
Feb 20081183021
Mar 2008571920
Apr 2008502010
May 2008262160
Jun 2008321660
Jul 2008201430
Aug 2008172040
Sep 2008264370
Oct 2008355820
Nov 2008285000
Dec 2008214631
Jan 20092034580
Feb 20092735770
Mar 20093237730
Apr 20092642050
May 20091941810
Jun 20091741600
Jul 20091791570
Aug 2009157960
Sep 20092011810
Oct 20093903170
Nov 20092662590
Dec 20091902040
Jan 20101711890
Feb 20101642410
Mar 20101952000
Apr 20102471740
May 20102031540
Jun 20101691100
Jul 2010154990
Aug 20101191061
Sep 20102081030
Oct 20104122390
Nov 20103561710
Dec 20101911300
Jan 20112471690
Feb 20112611440
Mar 20112781780
Apr 20112331430
May 2011213970
Jun 2011168900
Jul 20111271190
Aug 20111271890
Sep 20111691780
Oct 20111813000
Nov 2011542160
Dec 201102560
Jan 20121461670
Feb 20123252510
Mar 20121961220
Apr 20122011350
May 20121681900
Jun 201278730
Jul 201223540
Aug 201226670
Sep 2012681090
Oct 2012103850
Nov 2012131730
Dec 201280400
Jan 201375540
Feb 201383330
Mar 201378500
Apr 2013103520
May 2013137840
Jun 2013105580
Jul 201382630
Aug 201398660
Sep 201395570
Oct 2013159860
Nov 2013182720
Dec 2013166570
Jan 2014197730
Feb 2014237540
Mar 2014126440
Apr 2014216550
May 2014135600
Jun 2014155700
Jul 2014113850
Aug 2014252680
Sep 2014213890
Oct 201418811039
Nov 20141241839767
Dec 2014907491332
Jan 2015610246123
Feb 201550521999
Mar 201534113912
Apr 20152931256
May 20152091165
Jun 201596632
Jul 201551353
Aug 2015687518
Sep 201591170
Oct 201561400
Nov 2015103650
Dec 2015128590
Jan 2016128690
Feb 2016182910
Mar 2016988226
Apr 2016165530
May 2016145760
Jun 2016112530
Jul 201689960
Aug 20161178124
Sep 20161438813
Oct 2016223932
Nov 2016166800
Dec 201614312471
Jan 201715820344
Feb 2017141710
Mar 2017139700
Apr 2017123760
May 2017159760
Jun 201782710
Jul 201789740
Aug 2017102800
Sep 2017911110
Oct 20171051200
Nov 201787970
Dec 2017851000
Jan 20181332290
Feb 20181052320
Mar 2018851180
Apr 20181051020
May 20181121080
Jun 2018121670
Jul 2018133940
Aug 2018111780
Sep 2018119870
Oct 2018143860
Nov 2018155960
Dec 2018164490
Jan 20191991750
Feb 2019179810
Mar 20192801150
Apr 2019267690
May 2019189850
Jun 2019142640
Jul 201985350
Total24867343341591