Assessment And Diagnosis

Question 1

Assessment

Answer 1

The process of identifying signs and symptoms of a disease or condition regarding the associated data for purpose of diagnosis

Question 2

Diagnosis

Answer 2

The process of determining the nature of a disease or condition through evaluation of a patients history, physical exam and resulting lab tests/imaging

Question 3

Reference standard test

Answer 3

Gold standard to which all diagnostic procedures are compared because it has been shown to be the more accurate

Question 4

Research studies on newly developed diagnostic test are:

Answer 4

Compared side by side to gold standard

Conducted on patients known to have the disease

Conducted on patients known not to have the disease

Question 5

Evaluating the validity of a diagnostic test study

Answer 5

Did participating patients present a diagnostic dilemma ( should present NO dilemma)

Did investigators compare the test to an appropriate independent reference standard

We’re those interpreting the tests and reference standard blind to results - should be blinded

Did the investigators perform the same reference standard to all patients regardless of their results under investigation - cannot use different gold standards

Question 6

Consider for the evidence of accuracy

Answer 6

Postoperative and negative predicative values (PPV/NPV)

Sensitivity

Specificity

Question 7

Sensitivity

Answer 7

Test is positive when the patient has the disease or condition

Characteristic of test itself

Question 8

Specific

Answer 8

Test is negative when the patent does not have the disease or condition

True negatives

Characteristic of test itself

Question 9

Sensitivity

Answer 9

A/a+c

Question 10

Specificity

Answer 10

D/b+d

Question 11

Positive predictive value (PPV)

Negative Predictive Value (NPV)

Answer 11

PPV - Percentage of patients with a positive test who actually have the disease

NPV- percentage of patients with a negative test who do not have the disease

Influenced by prevalence, clinical value, not a characteristic of test

Question 12

Positive Predictive value equation (PPV)

Answer 12

A/a+b

Question 13

Negative predicative value (NPV) equation

Answer 13

D/c+d

Question 14

Prevalence

Answer 14

Proportion of individuals in a population having the diseases or characteristic

Disease recurrence adds to prevalence

Reduce prevalence : people die

Question 15

Incidence

Answer 15

The number of new cases that develop in a given period of time

Question 16

Prevalence and PPV/NPV

Answer 16

As prevalence of the disease in the sample increases

PPV increased

NPV decreases