What does Ci mean in medicine?

In medicine, "Ci" often refers to "confidence interval," which is a statistical range that estimates the uncertainty around a measure, such as a treatment effect or a prevalence rate. It provides a range of values within which the true parameter is expected to lie with a certain probability, commonly 95%. Additionally, "Ci" can also denote "cubic inch" in contexts related to measurements of volume for medical devices or implants.