Dx Reasoning And Differential Diagnosis

Question 1

Diagnosic reasoning

Answer 1

Scientific process in which the practitioner suspects the cause of a patient’s signs and symptoms.

Question 2

Pertinent positive

Answer 2

The present of a symptom of a sign related to a specific problem

Question 3

Pertinent negative

Answer 3

The absence of a sign or symptom that if present, suggests a diagnosis

Question 4

Occam’s razor

Answer 4

Single disease explains multiple symptoms in a patient

Question 5

Sensitivity

Answer 5

• based on patients with the disease

- is also known as the true positive rate or the proportion of positive test results in individuals with a dx

Question 6

Specificity

Answer 6

Patients without the dx.

Also known as a true negative rate or the proportion of negative test results in individuals without the dx

Question 7

Likelihood ratio

Answer 7

Provides unitary measure of the operating characteristics of a sign, symptom, or test expressed as a ratio.

LR= sensitivity/1-specificity

Question 8

Positive predictive value

Answer 8

Used to predict used to predict the actual probability of a disease for a patient with a positive result.

PV=TP/ all positive = TP\ (TP+FP)

Question 9

Negative predictive values

Answer 9

Frequency of non disease in persons with negative test results or the probability of not having the dx if the test is negative or if the sign or symptoms is present

A high negative predictive value is consistent with a high specificity value

Question 10

Prevalence

Answer 10

Refers to the proportion with disease in the population of interest

Equal to the number with disease (TP+FN) divided by the total number in the population.