Diagnosis: A question about the process for determining that someone has a particular disease or injury. These questions often evaluate the effectiveness of a diagnostic test. They can look at the accuracy of a test (sensitivity and specificity) as well as how that test might be used in an intervention strategy. This type of question can also include the act of finding the cause of a series of symptoms.
If you’re a doctor, you may want to know if the amount of protein in a urine sample can help you accurately determine whether a patient has kidney disease.
Example: In elderly males with suspected kidney disease, what is the accuracy of markers for the levels of protein in a urine sample for diagnosing kidney disease?
Prognosis/predictions: A question that explores what happens to patients over the course of a disease or health condition.
If you want to know the typical outcomes of kidney dialysis for people like your father, you’re asking a prognosis/prediction question.
Example: For male patients 60 years and older, how does kidney dialysis influence the risk of developing dry or itchy skin during the winter?