We are receiving a lot of questions about relevant analyses in the Analyse-it Method Validation edition to help in evaluating new diagnostic tests in the fight against COVID-19. Below are some quick links that will help, but contact us if you have questions - we are working as normal.
Also see our latest blog post: Sensitivity/Specificity and The Importance of Predictive Values for a COVID-19 test
Odds ratios are the increase or decrease in odds associated with a unit change of the predictor, all other predictors been held constant.
Although mathematically the log odds ratios are easier to work with, when it comes to interpretation, it is more natural to use the odds ratios. Unlike the log odds ratio, the odds ratio is always positive. A value of 1 indicates no change. Values between 0 and less than 1 indicate a decrease in the probability of the outcome event. Values greater than 1 indicate an increase in the probability of the outcome event.
When the predictor variable is a categorical variable, the odds ratio is the increase or decrease in odds over the baseline category.