QA, QC, lab math, specimen processing

What is percent concentration?

an expression of concentration that does not give MW info

What is the formula for percent concentrations?

What is molarity?

concentration of a solute within a solution, or relative number of reactant particles

What is the equation to calculate molarity?

What is inverse proportion?

The determination of a working solution from a stock solution

What is the equation for inverse proportions?

C1V1 = C2V2

what is statistics?

the mathematical analysis and evaluation of collected data

What is a statistic?

a number that summarizes data

What is descriptive statistics?

summary of features from a single group of data (example: mean)

What is inferential statistics?

inferring findings from a small group to a large population

what is the equation of standard deviation?

What is mode?

the number value in a dataset that occurs most frequently

What is median?

The value that occurs in the middle of all values

What is the coefficient of variation?

comparison of relative ability between two sets that do not have the same units

What is the equation for coefficient of variation?

What comprises whole blood?

plasma, cells, platelets

What is serum?

the remainder of whole blood after the blood has clotted, there is no anticoagulant present

What is plasma?

Whole blood that has been treated with anticoagulant, it contains fibrinogen and other clot factors

What are some factors that affect test result quality?

anticoagulant use, collection technique, diet, health status, specimen handling

What does normal serum look like?

clear, pale to medium yellow

What does hemolyzed serum look like?

pink/orange/red tinged serum, still clear

What does icteric serum look like?

bright yellow or green

What does lipemia serum look like?

cloudy or turbid

what are four factors in specimen handling?

1. maintain an ID

2. specimen preservation

3. specimen separation

4. specimen transport

What are some controllable factors for specimens?

posture, bed rest, exercise, circadian rhythm, diet, smoking, alcohol

What are some non-controllable factors for specimens?

sex, age, ethnicity, environment, medical conditions

What is quality?

a degree of excellence

What are some analytical variables for specimens?

statistics for QC, reagent deterioration, and bad calibration

What is statistical QC?

the monitoring and performance of analytical methods utilizing control material and charts

what is the most common control chart used for QC?

Levey-Jennings chart

What are Westgard multirules?

rules to detect subtle changes in QC that warrant warnings, re-runs, or rejections

What is the 1_2s rule?

One control value that exceeds the mean ± 2 stdev.

What is the 2_2s rule?

Two consecutive control values that exceeds the mean ± 2 stdev.

What is the 1_3s rule?

One control value that exceeds the mean ± 3 stdev.

What is the 4_1s rule?

Four consecutive control values that exceeds the mean ± 1 stdev.

What is the R_4s rule?

One control value that exceeds the mean + 2 stdev AND one control value that exceeds the mean - 2 stdev.

What is the 10_x rule?

10 consecutive controls that fall on the same side of the mean, either (-) or (+)

Which of the westgard multirules are considered a systematic issue?

2_2s, 4_1s, and 10_x because they are all consecutive

Which of the westgard multirules are considered a random issue?

1_3s, R_4s because they are isolated events

Which of the westgard multirules is considered a warning?

1_2s because it could just be some variation in QC

What are some procedures for non-statistical QC?

• delta check, or correlation of test results from the same patient

• avg. of normal, or assessment of all patient values

• pattern recognition, or combinations of trends in test values

What is QA?

quality assurance is an assurance practice that the laboratory meets standards