Calculate how many patients/participants you need in a study

The Emergency Medical Journal (EMJ) has published a study on sample size estimation which may help you in this area.

However NIHR applications, clinical trials and other forms of study will require formal sample size/power calculations.  Applicants are strongly advised to seek formal statistical advice from:

• Research Design Service (NIHR applications only)
• University colleagues
• Other formal statistical advisors

NIHR guidance for sampling and sample size calculation