Clues And Probability Flashcards
What is a clue?
Any piece of info gained from patients (directly or indirectly) that aids in problem solving and diagnosis of a condition
What are positive clues
Present and abnormal
Easiest to detect
What are negative clues
Harder to detect
Absence of something
Cannot be seen or heard
What three things are used to evaluate clinical clues
Clinical expertise
Diagnostic strategy
Clues (- & +)
What are the 6 principles for evaluating clinical evidence
Reliability Validity Sensitivity Specificity Predictive values Likelihood ratios
What is Bates theorem of probability
A formula that describes how to update the probabilities of hypotheses when given evidence
When is Hayes theorem helpful
Useful when considering:
The incidence of a disease in a population
The incidence of a specific clue in a disease
The incidence of this symptoms in a persons who do not have the disease
What does true positive mean
The patient has the disease and the test is positive
What does false positive mean
The patient does not have the disease but the test is positive
What does true negative mean
The patient does not have the disease and the test is negative
What does false negative mean
The patient has the disease but the test is negative
What does sensitivity mean
The proportion of patients with the disease who have a positive test
TP test
When is a high sensitivity important
Where the test is used to identify a serious but treatable disease
What is specificity
The proportion if patients without the disease with a negative test
TN rate
What is incidence
The rate at which new cases occur in a population at risk during a specific period
