Letters RCGP’s oral contraception study

Authors’ reply

BMJ 2008; 336 doi: https://doi.org/10.1136/bmj.39450.650289.3A (Published 10 January 2008) Cite this as: BMJ 2008;336:60
  1. Philip C Hannaford, professor1,
  2. Alison M Elliott, senior research fellow1,
  3. Lisa Iversen, research fellow1,
  4. Amanda J Lee, professor of medical statistics1,
  5. Sivasubramaniam Selvaraj, research fellow2,
  6. Valerie Angus, data manager3
  1. 1Department of General Practice and Primary Care, University of Aberdeen, Aberdeen AB25 2AY
  2. 2Centre for Rural Health, Beechwood Business Park, Inverness
  3. 3College of Life Sciences and Medicine, University of Aberdeen, Aberdeen
  1. p.hannaford{at}abdn.ac.uk

    We presented all relevant results so that readers could decide for themselves whether their interpretation of our findings fits with ours. Brind thinks that the analysis in which both ever and never users lost to follow-up before the age of 38 were excluded (adjusted relative risk 0.95, 95% confidence interval 0.88 to 1.02) shows serious bias and invalidates the main dataset results in which only never users younger than 38 were excluded (0.88, 0.83 to 0.94). …

    View Full Text

    Sign in

    Log in through your institution

    Free trial

    Register for a free trial to thebmj.com to receive unlimited access to all content on thebmj.com for 14 days.
    Sign up for a free trial

    Subscribe