Endgames

Statistical question

Number needed to treat

BMJ 2009; 338 doi: 10.1136/bmj.b2493 (Published 24 June 2009)
Cite this as: BMJ 2009;338:b2493

Access to the full text of this article requires a subscription or payment. Please log in or subscribe below.

  1. John Fletcher, clinical epidemiologist
  1. 1BMJ, London WC1H 9JR
  1. jfletcher{at}bmj.com

    Two weeks after entry to a trial of antibiotics to treat symptoms of chest infection, 25% of people receiving placebo and 15% of people receiving antibiotics still had symptoms. What is the number needed to treat in this trial for antibiotics to cure symptoms at two weeks?

    • a) 10

    • b) 1.18

    • c) 10%

    • d) 4

    • e) 6.7

    Answer

    a—Number needed to …

    Access to the full text of this article requires a subscription or payment

    Subscribe

    Article access

    Article access for 1 day

    Purchase this article for £20 $30 €32*

    The PDF version can be downloaded as your personal record

    * Prices do not include VAT

    Rapid responses

    THIS WEEK'S POLL

    BMJ most popular