Franz Wiesbauer explains how to express prognosis with the help of life tables and why this is essential to understanding Kaplan Meier curves.
Franz Wiesbauer looks at how a doctor can work out the probability of disease when confronted with a positive or a negative test result and how the prevalence of a given disease affects this probability.
Franz Wiesbauer looks at the impact of specificity and sensitivity on positive predictive value (and thus validity of a test) and why one has a bigger impact than the other.
Types of study design arranged by level of evidence, from low to high
Retrospective studies are designed to analyse pre-existing data, and are subject to numerous biases as a result. Types of retrospective studies include: case series; retrospective cohort studies; case-control studies