Can You Trust the Test?
A patient has the disease and the test result is positive.
What is a true positive?
What percentage of values will fall between ±2 SD in a Gaussian (normal) distribution?
95.5%
Tube contains EDTA and is commonly used for CBC testing.
Lavendar
This statistical measure represents the average value of a set of data.
Mean
patient extending an arm
impled consent
A patient does not have the disease and the test result is negative.
What is a true negative?
Calculate the mean
5.1 mmol/L, 4.7 mmol/L, 5.2 mmol/L, 4.4 mmol/L, 4.9 mmol/L, 5.2 mmol/L, 5.4 mmol/L
6.9mmol/L
Tube contains sodium citrate and is used for coagulation studies
light blue
This statistical measure is the value that occurs most frequently in a data set.
What is the mode?
The primary antiseptic for routine venipuncture is:
isopropyl alcohol
It is how close a test result is to the true value.
What is accuracy?
This statistic measures the amount of variation or dispersion around the mean.
Standard deviation
Tube contains heparin and is commonly used for chemistry testing
Dark green
(Standard deviation/mean) x 100
Coefficient of Variation
The preferred site for a venipuncture procedure
Median cubital vein
Both Levey-Jennings charts and Westgard rules
What are tools used to monitor quality control?
Calculate the coefficient of variation for chloride QC. The mean value was 104 mmol/L and the standard deviation was calculated to be 3.5 mmol/L.
3.40%
Tube color can be used for chemistry and is commonly known as PST.
What is PST
Five QC values are 98, 100, 102, 100, and 100. Calculate the mean.
100
The larger the gauge the ___________ the needle.
What is smaller?
Calculate sensitivity: 90 true positives and 10 false negatives.
Sensitivity=TP/
FN+TP×100
90%
Calculate the +/- 2 SD range for a level 3 hemoglobin control. The mean value was 22.4 g/dL, and the standard deviation value was 1.2.
20 to 24.8 g/dL
Correctly list the order of draw.
Stop light red stay put green light go
A quality control pattern showing results gradually moving in one direction over time is called this.
What is a trend?
This liquid portion of blood contains fibrinogen and clotting factors.
What is plasma?