Confidence Intervals
Reviewed and revised 26 August 2015
OVERVIEW
Confidence intervals are the range around the sample mean within which you predict the means of the population to lie
CALCULATION
- using a standard normal distribution curve, 95% of the sample means should lie within 1.96 SE above and below the population mean. This the 95% CI for the population mean.
- Standard Normal Distribution Curve: CI = sample mean +/- (z0.05 x SE)
- T-test: CI = sample +/- (t0.05 x SE)
CAUSES OF WIDE CONFIDENCE INTERVALS
- small sample
- large variance within sample
INFORMATION
- precision of sample mean as an estimation of the population mean.
- more information on significance of p-value.
- allows clinical relevance to be made.
- allows for graphical representation between several means.
- if OR presented with CI and includes 1 -> there is no difference between the two groups.
- if p value presented with CI that includes 0 -> there is no difference between the two groups.
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC
