Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1995 Sep 2;311(7005):619-20.
doi: 10.1136/bmj.311.7005.619.

Probability of adverse events that have not yet occurred: a statistical reminder

E Eypasch  1 , R Lefering, C K Kum, H Troidl
Affiliations

Probability of adverse events that have not yet occurred: a statistical reminder

E Eypasch et al. BMJ. .

Abstract

The probability of adverse and undesirable events during and after operations that have not yet occurred in a finite number of patients (n) can be estimated with Hanley's simple formula, which gives the upper limit of the 95% confidence interval of the probability of such an event: upper limit of 95% confidence interval = maximum risk = 3/n (for n > 30). Doctors and surgeons should keep this simple rule in mind when complication rates of zero are reported in the literature and when they have not (yet) experienced a disastrous complication in a procedure.

PubMed Disclaimer

References

    1. Am J Surg. 1991 Mar;161(3):385-7 - PubMed
    1. Am J Surg. 1992 Feb;163(2):221-6 - PubMed
    1. Endoscopy. 1992 May;24(4):252-61 - PubMed
    1. Surgery. 1992 Sep;112(3):497-501 - PubMed
    1. Surg Endosc. 1993 Jul-Aug;7(4):334-8 - PubMed