Can a confidence interval contain 1?
The confidence interval indicates the level of uncertainty around the measure of effect (precision of the effect estimate) which in this case is expressed as an OR. If the confidence interval crosses 1 (e.g. 95%CI 0.9-1.1) this implies there is no difference between arms of the study.
What is single observation?
Case reports in medicine are conventionally assumed to be something of rare occurrence of disease or medical observations. These can be in form of a single observation which makes the observer think and when published allows many more to think about it.
How to calculate a confidence interval for a small sample?
Because the sample size is small, we must now use the confidence interval formula that involves t rather than Z. The sample size is n=10, the degrees of freedom (df) = n-1 = 9. The t value for 95% confidence with df = 9 is t = 2.262. Substituting the sample statistics and the t value for 95% confidence, we have the following expression:
What is the confidence interval for systolic blood pressure?
Interpretation: A point estimate for the true mean systolic blood pressure in the population is 127.3, and we are 95% confident that the true mean is between 126.7 and 127.9. The margin of error is very small here because of the large sample size
How are confidence intervals used in public health?
Estimates based on samples are, of course, subject to sampling error (random error), and it is important to evaluate the precision of our estimates. In public health this is most commonly done by computing a confidence interval.
Is the 95% confidence interval the same for men and women?
Note, however, that some of the means are not very different between men and women (e.g., systolic and diastolic blood pressure), yet the 95% confidence intervals do not include zero. This means that there is a small, but statistically meaningful difference in the means.