Intended for healthcare professionals

Endgames

Sample size: how many participants are needed in a trial?

BMJ 2013; 346 doi: https://doi.org/10.1136/bmj.f1041 (Published 15 February 2013) Cite this as: BMJ 2013;346:f1041

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: February 2013 to June 2020

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AbstractFullPdf
Feb 201311981058229
Mar 201331426059
Apr 2013578226
May 20136010144
Jun 2013458142
Jul 2013337338
Aug 2013167232
Sep 2013265728
Oct 2013394621
Nov 2013656424
Dec 2013396527
Jan 2014265722
Feb 2014235420
Mar 20144710557
Apr 2014275831
May 2014515223
Jun 2014394925
Jul 2014020284
Aug 2014808052
Sep 2014252826
Oct 2014202514
Nov 2014133319
Dec 2014244422
Jan 2015615739
Feb 2015344122
Mar 2015543732
Apr 2015412825
May 2015285619
Jun 2015312114
Jul 201544118
Aug 2015282623
Sep 2015571712
Oct 2015682211
Nov 2015553528
Dec 2015352311
Jan 201659219
Feb 2016413710
Mar 2016442110
Apr 201628167
May 2016501910
Jun 201625147
Jul 201636122
Aug 201641128
Sep 201638127
Oct 201642138
Nov 2016441711
Dec 201646135
Jan 2017312814
Feb 201736274
Mar 2017522610
Apr 201731119
May 201737165
Jun 201731239
Jul 201743163
Aug 201738119
Sep 201746184
Oct 2017812914
Nov 201783236
Dec 201738207
Jan 201877235
Feb 201885236
Mar 2018693810
Apr 2018995213
May 2018101246
Jun 201881247
Jul 2018763513
Aug 20181494311
Sep 201878266
Oct 2018147395
Nov 2018152418
Dec 2018783612
Jan 201995367
Feb 201960288
Mar 2019412310
Apr 201952218
May 2019302110
Jun 201939185
Jul 20192754
Aug 20193470
Sep 201924116
Oct 201957167
Nov 201950158
Dec 201940126
Jan 202043144
Feb 2020112194
Mar 202056183
Apr 20205453
May 202077115
Jun 2020800
Total593542591597