Question 1

A graph that shows the difference between your laboratory result and a comparative method results along the x-axis and the percent difference along the y-axis is referred to as which of the following?

Accepted Answer

A)   Levy-Jennings graph
B)   Linear regression graph
C)   CUSUM graph
D)   Bias graph D

Question 2

Analysis of variance (ANOVA) is an appropriate statistics to evaluate three or more sets of data among each other, but it does NOT reveal:

Accepted Answer

A)   Which set of data is bias.
B)   Which set of data is most accurate.
C)   Which set of data is most precise.
D)   Which set of data is not in agreement with the other data. D

Question 3

Recovery experiments, testing proficiency samples and estimating bias are all examples of procedures used to assess:

Accepted Answer

A)   Accuracy.
B)   Precision.
C)   Coefficient of determination.
D)   Total error. A

Question 4

Which of the following is a procedure that is used to substantiate the continued accuracy of the test system throughout the laboratory reportable range of the tests result of the test system?

Accepted Answer

A)   Quality control
B)   Calibration
C)   Bias testing
D)   Regression analysis

Question 5

The term patient demographics refers to which type of information that is entered into a laboratory information system?

Accepted Answer

A)   Patient-specific information, for example, name, age, and date of birth
B)   Patient-specific information, for example, the total volume of urine collected in a 24-hour period for a creatinine clearance
C)   Patient-specific information, for example, their mother's and father's first and last name
D)   Patient-specific information, for example, where they were born and their religious preference

Question 6

A significant limitation of least squares regression analysis is:

Accepted Answer

A)   A large confidence intervals may result is false positives.
B)   Outliers will not impact the results.
C)   It may result in an incorrect decision of analytical reproducibility.
D)   Nonlinearity of the data will affect both the slope and intercept.

Question 7

The term that describes a procedure in which the CLS compares two consecutive laboratory results on a patient is:

Accepted Answer

A)   Discordant check.
B)   Correlation check.
C)   Limits check.
D)   Delta check.

Question 8

A glucose result that is greater than the lower limit of detection of the method should be reported as which of the following?

Accepted Answer

A)   Zero
B)   Less than the detection limit value
C)   The actual concentration value given by the analyzer or as calculated by the operator
D)   Greater than the detection limit value

Question 9

The McNemar statistics using a two by two contingency table is useful for evaluating which of the following?

Accepted Answer

A)   Correlation between two qualitative assays for example urine ?-hCG
B)   The degree of association between two sets of data
C)   Correlation between two quantitative assays for serum ?-hCG
D)   Determining the source of error in a qualitative assay

Question 10

The results of a precision study urea nitrogen are shown below. What is the per cent coefficient of variation for the study?
Mean = 15 mg/dL
Standard deviation = 1.5 mg/dL
Variance = 2.0 mg/dL

Accepted Answer

A)   1.5%
B)   2.0%
C)   10.0%
D)   15.0%

Question 11

A deteriorating light source in a spectrophotometer can result in which of the following types of errors?

Accepted Answer

A)   Systematic
B)   Systemic
C)   Type I
D)   Type II

Question 12

Linearity is useful for assessing:

Accepted Answer

A)   Slope and bias of an analytical method.
B)   A large correlation coefficient.
C)   Intercept and p value of analytical method.
D)   Slope and intercept of an analytical method.

Question 13

Which of the following statements usually determines the acceptable range when evaluating quality control results?

Accepted Answer

A)   The range that includes 75% of the results
B)   The range encompassed by ±2.5 standard deviations
C)   The 95% confidence interval of the mean
D)   The central 68% of results

Question 14

A type II error is defined as which of the following?

Accepted Answer

A)   A serious misinterpretation of quality control rule violation
B)   Erroneously accepting the null hypothesis, with the result that a real difference is not detected.
C)   Erroneously rejecting the null hypothesis or proclaiming a difference to exist when one does not
D)   Ignoring a large bias between two methods

Question 15

A 13s quality control rule violation is defined as:

Accepted Answer

A)   One control result that exceeds ±3 s.
B)   One control result that exceeds ±1.3s.
C)   Three consecutive controls results that exceed ±3 s.
D)   One control result that exceeds ±4 s.

Question 16

Which of the following statistics is used to qualify the strength of the relationship between two variables?

Accepted Answer

A)   z- value
B)   standard error of the difference
C)   Confidence interval
D)   Correlation coefficient

Question 17

Which of the following practices is inappropriate when establishing quality controls ranges?

Accepted Answer

A)   Exclusion of any quality control results greater than ±2 standard deviation from the mean
B)   Compare your data to the manufacturer of the quality control material.
C)   Gather quality control data for a long period of time if necessary.
D)   Using control results from all shifts on which the assay is performed

Question 18

A cross-reacting compound in a serum sample may result in which of the following?

Accepted Answer

A)   A reliable result
B)   A precise result
C)   An accurate result
D)   A discordant result

Question 19

Which of the following is an example of an inferential statistic?

Accepted Answer

A)   Mean
B)   Standard deviation
C)   F- test
D)   Correlation coefficient

Question 20

A urea nitrogen result is falsely elevated and it was discovered that the previous sample on the sample carousel has abnormally high serum glucose. Which of the following can cause this error?

Accepted Answer

A)   Pipetting an extra volume of diluents into the sample with the falsely elevated glucose
B)   Carryover
C)   A leak in the reagent-dispensing probe
D)   Double pipetting of the sample with the elevated glucose result

Exam 3: Laboratory Statistics, Method Development and QC