Laboratory Statistics Flashcards
Which of the following is not included in the measure of variability?
a) Range
b) SD
c) Coefficient of Variation
d) Mode
d) Mode
Measure of Center/Central Tendency
- Mean
- Median
- Mode
Best indicator of Precision
a) SD
b) Mean
c) Coefficient of Variation
d) None of the choices
c) Coefficient of Variation
What is the ideal SD range?
a) +/-1SD
b) +/-2SD
c) +/-3SD
d) +/-4SD
b) +/-2SD
*Question lifted from Review Handbook of Maria Teresa Rodriguez p. 36
The range limit for +/-2SD:
a) 68%
b) 99.5%
c) 99.7%
d) 95%
d) 95%
Which of the following statements best describes the purpose of a reference interval in laboratory medicine?
a) represents the range of values within which a patient’s test result will always fall.
b) used to compare an individual patient’s test result against a healthy population to assess whether it is within normal limits.
c) only applicable to blood tests and not other types of laboratory tests.
d) determined solely by the laboratory equipment and does not depend on the population used for data collection.
b) used to compare an individual patient’s test result against a healthy population to assess whether it is within normal limits.
How many individuals are required when a transference studies fail?
a) 20 study individuals
b) 120 study individuals
c) 10 study individuals
d) 100 study individuals
b) 120 study individuals
At least 120 study individuals are required when there’s no existing RI or when a transference studies fail
A transference is done to confirm the validity of an existing RI. It requires at least 20 study individuals and the RI is adopted when >10% of the subject fall outside the range.
a) 1st statement is true; 2nd statement is false
b) 1st statement is false; 2nd statement is true
c) Both statements are true
d) Both statements are false
a) 1st statement is true; 2nd statement is false
RI should be adopted when ≤10% of the subject fall outside the range
It is used to determined if there is statistically significant difference between the two methods used to measure the accuracy of the data.
a) F-test
b) T-test
c) Both of these
d) None of these
b) T-test
mnemonics:
Mean
Accuracy
T-test
It is the ability of the method to detect the smallest concentration of an analyte that is desired for screening test.
a) Diagnostic sensitivity
b) Analytical sensitivity
c) Analytical specificity
d) Diagnostic specificity
b) Analytical sensitivity
Detects the individuals with given disease
Diagnostic sensitivity
It compares the statistically significant difference between SD of two groups of data:
a) T-test
b) F-test
c) Coefficient of variation
d) None of the above
b) F-test
mnemonics:
SD
Precision
F-test
It indicates the absence of a disease in which the individuals are truly tested with negative results:
a) a) Diagnostic sensitivity
b) Positive predictive value
c) Negative predictive value
d) Diagnostic specificity
c) Negative predictive value
Reference method in linear regression
a) X
b) Y
c) Either
d) Neither
a) X
A Gaussian distribution is usually:
a) Bell-shaped
b) Uniform
c) Skewed
d) Rectangular
a) Bell-shaped
In establishing control limits, these should be taken into consideration, except:
a) minimum of 40 observations is recommended for an initial estimate of standard deviation
b) +/-2SD is the only reference point
c) mean and SD values for the unassayed controls should also be determined
d) when changing the control sample to a new lot number, use the newly calculated mean value and retain the previous SD value
a) minimum of 40 observations is recommended for an initial estimate of standard deviation
