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Flashcards in Lab Medicine Deck (39)
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1
Q

Accuracy

A

how closely the test results correspond to the true value or “gold standard.”

2
Q

Precision

A

How reproduce-able the results are with repeat testing of the same specimen

3
Q

Specificity

A

measures TN–> the percentage of persons WITHOUT the disease of interest with negative test results–>higher specificity of the test, the more likely it is that persons without the disease of interest will be excluded from consideration of having the disease

4
Q

What kind of test is used to clinically rule IN the disease?

A

Specificity (SPIN)

5
Q

T/F: The lower the specificity, the higher the chance of a false positive result

A

TRUE

6
Q

Sensitivity

A

measures TP –> higher the sensitivity, the more likely to detect people WITH the dz

7
Q

What is used to clinically to rule OUT the presence of the disease in an individual

A

Sensitivity (SNOUT)

8
Q

Predictive value

A

Measures concerning to estimation of the probability of the presence or absence of disease.

9
Q

Positive PV

A

percent of persons with a positive test result who DO HAVE the disease in question

10
Q

Negative PV

A

percentage of persons with a negative test result who DO NOT HAVE the disease in question

11
Q

False positive

A

lab testing that identifies abnormalities that are NOT present.

12
Q

False negative

A

lab testing that fails to identify abnormalities that ARE present.

13
Q

Prevalence

A

the proportion of a population found to have a condition (typically a disease or risk factor) at a particular time.

14
Q

Likelihood Ratio

A

Probability of a result in a patient with or without disease

15
Q

Negative LR

A

Probability of negative test in non-diseased person/ Probability of negative test in a diseased person

16
Q

Pretest probability

A

the probability of the target disorder before a diagnostic test result is `known

17
Q

Posttest probability

A

the probability of the presence of a condition (disease) after a diagnostic test.

18
Q

Gold Standard

A

most accurate measure

19
Q

Narrative result

A

descriptive values (ie: path report/ Chest Xray report)

20
Q

five major reasons for ordering a laboratory measurement

A

1) Discover occult (not accompanied by readily discernible signs or symptoms) disease or recurrent disease
2) Confirm a suspected diagnosis
3) Differentiate among possible diagnoses
4) Determine the stage, activity, or severity of disease
5) Assess and monitor the effectiveness of therapy or treatment

21
Q

Qualitative result

A

Yes/No or Positive/Negative (ie: pregnancy test, rapid strep)

22
Q

Quantitative

A

Numerical

23
Q

Reference Interval

A

range of “normal” values

24
Q

T/F: 1 in 20 “normal” tests will have test results outside of the reference range.

A

TRUE

25
Q

Basic Metabolic Profile (BMP):

A

common serum electrolytes (Na+, K+, Cl-), carbon dioxide content, blood urea nitrogen, Ca++, creatinine, and glucose

26
Q

Complete Metabolic Profile (CMP):

A

all BMP components plus albumin, alanine aminotransferease (ALT), aspartate aminotransferease (AST), total bilirubin, and total protein

27
Q

erythrocyte sedimentation test

A

non-specific test; increases in ESR (erythrocyte sedimentation rate) = infection, inflammation, and plasma cell dyscrasias

28
Q

spun hematocrit

A

percentage volume of blood that is composed of erythrocytes (RBCs)

29
Q

STAT laboratory tests

A

needed immediately; given highest priority

30
Q

pinworm prep

A

Test for the presence of pinworm eggs on the anus

Firmly press the sticky side of a strip of tape over the anal area for a few seconds. The eggs stick to the tape. The tape is then transferred to a glass slide, sticky side down, where it can be examined

31
Q

dipstick urinalysis

A

tests urine for protein; pH; specific gravity; bilirubin, bile, and urobilinogen; blood and hemoglobin; leukocyte esterase; nitrite; glucose; and ketones

32
Q

fecal occult blood testing (FOBT):

A

simple screening test, detects presence of blood in stool

33
Q

common sources of error that can affect the quality and variation of laboratory tests

A

patient variables (ie: BMI, age, gender, meds, pregnant, smoker, etc)

speciment collection variables (ie: posture, time of collection, fastings, presence of IV, etc)

specimen handling variables (ie: sunlight, temp, evaporation, hemolysis, lipemia, etc).

34
Q

urine pregnancy test

A

detects the presence of a hormone called human chorionic gonadotropin (hCG) in urine

35
Q

wet mount

A

vaginal discharge is placed on a slide in a salt solution to help detect the cause of vaginitis or vulvitis. The slide is looked at under a microscope for bacteria, yeast cells, trichomoniasis (trichomonads), white blood cells that show an infection, or clue cells that show bacterial vaginosis.

36
Q

potassium hydroxide (KOH) mount

A

tests for yeast infection – A sample of the vaginal discharge is placed on a slide and mixed with a solution of potassium hydroxide (KOH). The KOH kills bacteria and cells from the vagina, leaving only yeast for easier detection of a yeast infection

37
Q

capillary blood glucose (CBG):

A

measures blood glucose level, performed by piercing the skin (typically, on the finger) to draw blood, then applying the blood to a chemically active disposable test-strip.

38
Q

ovulation test

A

helps determine expected ovulation by picking up the luteinizing hormone (LH), LH is always present in urine and increases 24-48 hours prior to ovulation

39
Q

what is the strongest predictor of risk?

A

age