Evidence Based Medicine

Question 1

Cage Mnemonic to assess Alcoholism

Answer 1

1. Have you ever tried to CUT down? 2. Do you get ANNOYED when others suggest you cut down? 3. Do you feel GUILTY about your drinking? 4. Do you ever drink an EYE OPENER in the morning?

Question 2

Five Steps of EBM

Answer 2

1. Asking foreground questions 2. Accessing the best evidence 3. Appraising that evidence critically 4. Applying that evidence to your patient or situation 5. Assessing the performance of your plan

Question 3

4 parts of a foreground question

Answer 3

(PICO) 1. Patient population 2. Intervention 3. Comparison or control 4. Outcome

Question 4

3 appraisal questions

Answer 4

1. Is the study valid? 2. What are the results? 3. How can the results be applied in your situation?

Question 5

Two by two table for diagnostic tests

Answer 5

Columns: Disease (+) / No Disease (-) Rows: Test positive (+) / Test Negative (-)

Question 6

Accuracy

Answer 6

TP + TN / total number

Question 7

Sensitivity

Answer 7

*Snout: SeNsitivity rules out - Test considered sensitive if positive the majority of time the decease is present - Just because sensitive, does not mean it’s diagnostic; i.g. mammography is highly sensitive but less than half that test positive have cancer

Question 8

Specificity

Answer 8

*Spin: Specificity rules in - Test is considered specific if high proportion of results are negative when the disease is absent - Western Blot for HIV testing: highly specific so reduces the undue trauma of a false-positive test

Question 9

Positive Predictive Value

Answer 9

Probability of Disease when Test Positive

• TP / (TP + FP)

Question 10

Negative Predictive Value

Answer 10

Probability of Health when Test is Negative

• TN / (TN + FN)

Question 11

Pre-test probabilty

Answer 11

• Prevalance of disease
• TP + FN / (Total)
• Unlike Sensitivity and Specificity, PPV & NPV are highly dependent upon prevalence