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Flashcards in statistics Deck (31)
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1

highly sensitive test is useful for what?

SNOUT: rule out
helps for screening purposes, as it negative results on these tests will help rule out diagnosis

2

what is a likelihood ratio?

probability of a given test result occurring in a patient with a disorder compared to a probability of the same result occurring in a patient without the disorder
- does NOT change with prevalence of the disease
- useful for >2 different studies
- positive LR: sensitivity/ (1- specificity)
- negative LR: (1-sensitivity)/ specificity

3

sensitivity vs specificity

- sensitivity: TP/ (TP+FN)
- specificity: TN/ (TN+FP)

4

PPV vs NPV

- DOES depend on disease prevalence
- PPV: (TP/TP+FP)
- NPV: (TN/TN+FN)

5

which studies use odds ratio?

- case control studies--> exposure of participants with the disease vs exposure of participants without the disease

6

which studies use relative risk?

cohort studies

7

attributable risk percent

risk of exposed- risk of unexposed/ risk of exposed

8

What is the basic premise for intention to treat analysis

Randomization
Blinding

9

What is a type II error and what is its relation with sample size and power?

Occurs when the alternative hypothesis is rejected but is actually true

Power and sample size increase will decrease type II error

10

What is a measurement bias?

Poor data collection leads to inaccurate results, usually not seen in randomized clinical trials

11

Calculating number needed to treat

1/ARR
1/risk of control-risk of case

12

define standardized mortality ratio

observed n of death/ expected n of death
adjusted measure of overall mortality
used in occupational epidemiology

13

What is a factorial study design?

experimental study design with 2 or more interventions and all combinations of intervention

14

what is length time bias?

when survival benefits of a screening tests are overstated due to including lots of benign slow progressing cases

15

What does external validity measure?

generalizability of the study to other populations

16

Initial evaluation tests for lead poisoning includes what?

CBC, serum iron and ferritin levels, and reticulocytes

17

Treatment of rosacea (erythema in central face associated with flushing, telangiectasias, pustules, recurrent chalazions)

topical metronidazole
- would need ophtho consult

18

Best initial test for polycythemia (elevated hemoglobin/hematocrit)

erythropoietin level test--- low is polycythemia vera, high is chronic hypoxia

19

erbs palsy serious complication, prognosis

diaphragmatic paralysis due to phrenic nerve involvement
- prognosis: good, 80% chance to full recovery

20

schizoaffective disorder ddx

psychosis without mood sx lasting for at least 2 weeks, with major mood episode concurrent w/ sx of schizophrenia

21

Hypertension after kidney transplant is caused by what? what lab values will change after using ace inhibitors?

- renal artery stenosis
- creatinine will increase after starting ace-i if ddx is renal artery stenosis

22

Parkinson's disease (bradykinesia, resting tremor, rigidity) initial treatment

levodopa
dopaminergic agonists (pramipexole, bromocriptine)

23

Lab and image findings of Paget's disease, diagnosis, treatment

- elevated serum and bone specific ALP
- calcium and phosphorus usually normal, elevated with fracture/immobilization
- lytic lesions or mixed on plain radiograph
- ddx: combo of radiographic findings and increased ALP, bone scan is more sensitive than x-ray
- tx: bisphosphonate

24

Good lab test to order for diagnosing chronic kidney disease when creatinine is elevated? Tx?

- urine protein levels
- Ace-i or ARBs for proteinuria

25

HIV patients with odynophagia, giant ulcers with no virus. Ddx and tx?

Aphthous ulcer
Prednisone

26

Clinical fx of thyrotoxicosis, elevated T3 and T4 and elevated TSH and serum alpha units leads to what ddx?

TSH secreting pituitary adenoma

27

Chronic prostatitis treatment

- first line: fluoroquinolones-- cipro or levo
- second line: TMP-SMX

28

Massive pulmonary embolism can cause pulmonary hypertension. What would the ECHO show?

- RV strain
- tricuspid issues

29

Management of acute aortic dissection

- pain control with morphine
- IV beta blocker for target systolic bp of 100-120 to decrease left ventricular contractility
- if not well controlled, add nitroprusside

30

Management of unstable angina in high risk patients

- coronary angiography then PCI/CABG if needed