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: January 2018 to July 2024

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AbstractFullPdf
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
Oct 201957167
Nov 201950158
Dec 201940126
Jan 202043144
Feb 2020112194
Mar 202056183
May 202077115
Jun 20203294
Jul 202088167
Aug 202072120
Sep 202084165
Oct 202055106
Nov 202057117
Dec 2020103276
Jan 2021109159
Feb 202168153
Mar 202173114
Apr 2021113193
May 2021103112
Jun 20218430
Jul 20212442
Aug 20219260
Sep 20213783
Oct 20213864
Nov 202151124
Dec 202150134
Jan 202235154
Feb 202234236
Mar 20223671
Apr 20225562
May 202249141
Jun 202257200
Jul 20223371
Aug 20224974
Sep 202251152
Oct 202273131
Nov 202257183
Dec 202293332
Jan 202361194
Feb 202382253
Mar 2023107131
Apr 2023149142
May 202348162
Jun 20232072
Jul 20233461
Aug 202323114
Sep 20238571
Oct 202359178
Nov 202359135
Dec 20237784
Jan 2024105342
Feb 202479253
Mar 20245593
Apr 202462207
May 20248971
Jun 202498120
Jul 20243320
Total52851335344