Epidemiology

Question 0

Prevalence

Answer 0

Measure of those with the disease in a population at a particular point in time

Question 1

Incidence

Answer 1

Measure of appearance of new cases

Question 2

Increasing prevalence and stable incidence can be attributed to:

Answer 2

Factors that prolong duration of disease (improved quality of care)

Question 3

Lead time bias

Answer 3

2 interventions are compared to diagnose a disease and one intervention diagnoses the disease earlier than the other without an effect on the outcome (survival). This would make it appear that the intervention prolonged the survival when it really just diagnosed the disease sooner.

Question 4

Measurement bias

Answer 4

Poor data collection with inaccurate results

Question 5

Observer bias

Answer 5

Obs (not participant) may be influenced by prior knowledge or details of the study that can affect the results

Question 6

Recall bias

Answer 6

Study participant is affected by prior knowledge to answer a question. More common in case control studies than randomized clinical trials

Question 7

Susceptibility bias

Answer 7

Type of selection bias where a tx regimen is selected for a pt based on severity of their condition, without taking into account other confounding variables

Question 8

A sensitive test has few false negatives and it rules ______ a disease.

Answer 8

OUT

Question 9

True positive rate

Answer 9

Sensitivity

Question 10

False positive rate

Answer 10

1-specificity

Question 11

Sensitivity vs specificity

Answer 11

Changing the cutoff point to increase the number of pts with the disease who test positive will increase the sensitivity, BUT it will also increase the number of pts without the disease who test positive–increasing the false positive rate–eventually decreasing the specificity

Question 12

Herpetic whitlow

Answer 12

Common viral infection of the hand, caused either by herpes simplex 1or 2. Uz self-limiting. Tzanck smear of the vesicles shows multi-nucleated giant cells.