ROC curve analysis — Flashcards

Flashcard 1: A high _____ test is useful for screening in diseases with low prevalence (sensitivity or specificity)

Answer: sensitivity

Flashcard 2: Sensitivity values approaching 100% is desirable for ruling _____ disease (in or out)

Answer: OUT

Flashcard 3: Negative LR < _____ is an indicator of a very useful diagnostic test

Answer: 0.1

Flashcard 4: Positive LR > _____ is an indicator of a very useful diagnostic test

Answer: 10

Flashcard 5: Under Hardy-Weinberg conditions, what is the expected frequency of an X-linked recessive disease in males? Females?

Answer: males - q females - q2 (if condition is survivable)

Flashcard 6: coefficient of determination (r2) (biostatistics)

Answer: measure of correlation 0 indicates no relationship 1 indicates perfect concordance

Flashcard 7: Pearson's correlation coefficient (r) (biostatistics)

Answer: measure of linear correlation -1 is perfect inverse relationship 1 is perfect direct relationship

Flashcard 8: What is the Chi-square (X2) test used for? (biostatistics)

Answer: compare proportions of categorical outcomes between two groups (not comparison of means!)

Flashcard 9: Which parameters, sens/spec or PPV/NPV are affected by prevalence of the disease in the population?

Answer: PPV/NPV

Flashcard 10: PPV (biostatistics)

Answer: Probability that a person actually has disease given a positive test result.

Extra: PPV = TP/(TP+FP)