Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition - Test Bank
TEST BANK
Tietz Fundamentals of
Clinical Chemistry and Molecular Diagnostics
Carl A. Burtis, David E. Bruns
7th Edition
, Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition - Test Bank
Table of contents
I. PRINCIPLES OF LABORATORY MEDICINE
1. Clinical Chemistry, Molecular Diagnostics, and Laboratory Medicine
2. Selection and Analytical Evaluation of Methods — With Statistical Techniques
3. Clinical Evaluation of Methods
4. Evidence-Based Laboratory Medicine
5. Establishment and Use of Reference Values
6. Specimen Collection, Processing, and Other Preanalytical Variables
7. Quality Management
II. ANALYTICAL TECHNIQUES AND INSTRUMENTATION
8. Principles of Basic Techniques and Laboratory Safety
9. Optical Techniques
10. Electrochemistry and Chemical Sensors
11. Electrophoresis
12. Chromatography
13. Mass Spectrometry
14. Enzyme and Rate Analyses
15. Immunochemical Techniques
16 Automation
17. Point-of-Care Instrumentation
III. ANALYTES
18. Amino Acids, Peptides, and Proteins
19. Serum Enzymes
20. Tumor Markers and Cancer Genes
21. Kidney Function Tests — Creatinine, GFR, Urea, and Uric Acid
22. Carbohydrates
23. Lipids, Lipoproteins, Apolipoproteins, and Other Cardiac Risk Factors
24. Electrolytes and Blood Gases
25. Hormones
26. Catecholamines and Serotonin
27. Vitamins, Trace Elements, Nutritional Assessment
28. Hemoglobin, Iron, and Bilirubin
29. Porphyrins and Porphyrias
30. Therapeutic Drugs and Their Management
31. Clinical Toxicology
32. Toxic Metals
IV. PATHOPHYSIOLOGY
33. Diabetes
34. Cardiovascular Disease
35. Kidney Disease
36. Physiology and Disorders of Water, Electrolyte, and Acid-Base Metabolism
37. Liver Disease
38. Gastrointestinal and Pancreatic Diseases
39. Disorders of Bone and Mineral Metabolism
40. Disorders of the Pituitary Gland
41. Disorders of the Adrenal Cortex
42. Thyroid Disorders
43. Reproduction-Related Disorders
44. Pregnancy and Prenatal Testing
45. Newborn Screening and Inborn Errors of Metabolism
46. Pharmacogenetics
V. MOLECULAR DIAGNOSTICS NEW!
47. Principles of Molecular Biology
48. Nucleic Acid Techniques and Applications
49. Genomes and Nucleic Acid Alterations
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
Chapter 01: Clinical Chemistry, Molecular Diagnostics, and Laboratory MedicineTest
Bank
MULTIPLE CHOICE
1. An individual working in a clinical chemistry laboratory is married to a sales representative
who works for a company that sells chemistry laboratory supplies. When the laboratory
manager requests a list of needed supplies, cost of supplies, and vendors, this individual only
recommends the spouse’s company as the vendor. This is considered to be a(n):
a. accounting issue.
b. possible conflict of interest.
c. maintenance of confidentiality issue.
d. problem with resource allocation.
ANS: B
Concern has been raised over the interrelationships between practitioners in the medical field
and commercial suppliers of drugs, devices, equipment, etc., to the medical profession.
Similarly, relationships have been scrutinized between clinical laboratorians and
manufacturers and providers of diagnostic equipment and supplies. These concerns led the
National Institutes of Health (NIH) in 1995 to require official institutional review of financial
disclosure by researchers and management of situations in which disclosure indicates potential
conflicts of interest.
DIF: 1 REF: Page 4-5 OBJ: 6 | 7
2. A patient visits her physician stating that her prescribed painkiller is not working to reduce
the pain following her recent surgery. A friend of the patient claims that the same painkiller
“worked wonders” to reduce her pain after the same surgery. The physician states that the
difference in the effect of the drug might be caused by , which is studied in
pharmacogenetics.
a. epidemiology
b. an inherited disease
c. a conflict of interest
d. a genetic variation in drug-metabolizing enzymes
ANS: D
Pharmacogenetics is the study of the genetic variation of drug metabolism between
individuals.
DIF: 1 REF: Page 3 OBJ: 1
3. John works in a molecular diagnostics laboratory and receives a blood sample that has the
name of a close friend printed on the bar-coded label. The genetic test that is ordered on the
friend’s sample would provide diagnostic information about a disorder that has a poor
prognosis, and the test is usually performed by John. He asks a fellow employee to analyze
the sample for him and not divulge the results. This ethical issue concerns:
a. confidentiality of patient genetic and medical information.
b. a conflict of interest.
c. resource allocation.
d. diagnostic accuracy.
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
ANS: A
Clinical laboratorians have long been responsible for maintaining the confidentiality of all
laboratory results, a situation made even more critical with the advent of increasingly
powerful genetic testing.
DIF: 1 REF: Page 4 OBJ: 6 | 7
4. Molecular diagnostic testing methods and results can be:
a. qualitative only.
b. quantitative only.
c. either qualitative or quantitative.
ANS: C
Molecular diagnostic methods can be either qualitative or quantitative in nature, depending on
the clinical need.
DIF: 1 REF: Page 3 OBJ: 5
5. Clinical epidemiology, which is the study of the patterns, causes, and effects of health and
disease in certain populations, has provided the clinical laboratory with methods that evaluate
the effects and outcomes of laboratory testing. This allows for a more effective:
a. process of determining the cost of the testing methods.
b. selection and interpretation of laboratory tests.
c. determination of the boundaries between the components of the clinical lab.
d. conduct assessment.
ANS: A
Clinical epidemiologists have introduced methods to evaluate the effects and value of
laboratory testing in healthcare. These developments are expected to play an increasing role in
the selection and interpretation of laboratory tests.
DIF: 1 REF: Page 3 OBJ: 4
6. Analysis of which one of the following by molecular diagnostic methods provides a measure
of processes that are ongoing at the time of blood sampling?
a. Genetic variation in an individual’s response to a drug
b. Circulating plasma nucleic acids
c. Malignant lymphomas
d. Histocompatibility
ANS: B
Molecular diagnostics, given its very high sensitivity, has been applied to the study of plasma
nucleic acids (or circulating nucleic acids). Plasma nucleic acids analysis has been made
possible by the discovery that dying cells in the body release their DNA and RNA into the
extracellular compartment and ultimately into the bloodstream, where they can be detected
and analyzed. Given their short half-life in circulation (less than 24 hours), plasma nucleic
acids provide a measure of processes that are ongoing at the time of blood sampling.
DIF: 1 REF: Page 3 OBJ: 5
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
7. A healthy individual with no clinical signs or symptoms of disease visits his physician for a
routine physical examination. Blood samples are collected and sent to the laboratory. The tests
requested on the sample are for general laboratory analyses, including a complete blood count,
a panel of general chemistry tests (including glucose, protein, cholesterol, and others), and an
analysis of urine. This type of testing in laboratory medicine is directed at:
a. confirming a clinical suspicion of disease.
b. selecting a treatment for disease.
c. ruling in a diagnosis.
d. screening for disease in the absence of clinical signs or symptoms.
ANS: D
Testing in laboratory medicine may be directed at (1) confirming a clinical suspicion; (2)
making, or ruling in, a diagnosis; (3) excluding, or ruling out, a diagnosis;, (4) assisting in the
selection, optimization, and monitoring of treatment; (5) providing a prognosis; (6) screening
for disease in the absence of clinical signs or symptoms; or (7) establishing and monitoring
the severity of a physiologic disturbance. The field of laboratory medicine includes clinical
chemistry and areas such as microbiology and hematology. The general tests ordered on this
healthy individual are done to screen the physiologic systems despite the absence of any
symptoms.
DIF: 2 REF: Page 2 OBJ: 2
8. The discipline involved in the selection, provision, and interpretation of diagnostic testing that
uses primarily samples from patients is:
a. clinical chemistry.
b. hematology.
c. laboratory medicine.
d. molecular diagnostics.
ANS: C
The term “laboratory medicine” refers to the discipline involved in the (1) selection, (2)
provision, and (3) interpretation of diagnostic testing that uses primarily samples from
patients.
DIF: 1 REF: Page 1 OBJ: 1 | 3
9. A male laboratorian works in the clinical chemistry laboratory of a large hospital. He is
approached by his friend, who is a representative of a drug company, and asked to analyze
some patient samples for drug levels of a specific drug that the representative’s company sells
and that these patients use. The representative wants to publish a report on the rate of drug
absorption and distribution of this drug and tells his laboratorian friend that he will personally
reimburse him for his time. What ethical issues come into play here?
a. Resource allocation and conflict of interest
b. Maintenance of confidentiality and publishing issues
c. Maintenance of confidentiality, conflict of interest, and publishing issues.
d. Resource allocation, maintenance of confidentiality, conflict of interest, and
publishing issues.
ANS: D
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
Resource allocation, maintenance of confidentiality, conflict of interest, and publishing issues
are being compromised by the representative and the laboratorian if the laboratorian follows
through with the request. Using laboratory resources for a study that has not been approved by
the institutional review board is a resource allocation issue, revealing results of laboratory
tests is a confidentiality issue, receiving money to run laboratory tests from an individual with
a direct interest in the laboratory results is a conflict of interest, and publishing the results of
the testing would possibly be considered fraudulent and inappropriate.
DIF: 2 REF: Page 4-5 OBJ: 3 | 6 | 7
TRUE/FALSE
1. Molecular diagnostics testing is only used by the clinical chemistry laboratory.
ANS: F
The discipline of molecular diagnostics, which entered the realm of laboratory medicine in
multiple forms and in multiple fields, includes but is not limited to the study of hematopoietic
malignancies, such as malignant lymphomas and leukemias; the existence of nonhost nucleic
acids (microorganisms, graft-donor, fetal nucleic acids during pregnancy); and assessment of
solid tumors.
DIF: 1 REF: Page 3 OBJ: 1 | 5
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
Chapter 02: Selection and Analytical Evaluation of Methods—With Statistical
Techniques
MULTIPLE CHOICE
1. A statistic is a:
a. constant that describes some particular characteristic of a population.
b. value calculated from the observations in a sample to describe a particular
characteristic of that sample.
c. complete set of all observations that might occur as a result of performing a
particular procedure according to specified conditions.
d. graphic device for displaying a large set of data.
ANS: B
A statistic is a descriptive measure of a sample; it is a value calculated from the observations
in a sample to describe a particular characteristic of that sample.
DIF: 1 REF: Page 10 OBJ: 3
2. A population mean (µ) is calculated by which one of the following formulae?
a. xi/N
b. (b 1)/SE(b)
c. (x2i x1i)
d. (x1 )2/N
ANS: A
The parameter most commonly used to describe the central location of a population of N
values is the population mean ():
DIF: 1 REF: Page 10 OBJ: 3 | 11
3. Which one of the following is the correct formula for calculating the percent coefficient of
variation of a set of measurements?
a. CV = standard deviation 100%
b. CV = standard deviation ÷ 100%
c. CV = (standard deviation ÷ mean) 100%
d. CV = (mean + standard deviation) ÷ 100%
ANS: C
The coefficient of variation is the measure of relative imprecision. The value of CV% is
determined by calculating the ratio of the SD to the mean multiplied by 100%.
DIF: 1 REF: Page 10 OBJ: 11
4. The type of method comparison that compares the average results between two analyses with
the differences between varying concentration values of the two analyses is referred to as a(n):
a. Deming analysis.
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
b. linear regression plot.
c. ordinary least-squares plot.
d. Bland-Altman difference plot.
ANS: D
When comparing values obtained with two different methodologies, the average values of the
results are plotted against the differences between the values obtained from the two methods.
This examines the differences at varying analyte concentrations to determine whether a
problem exists at a certain concentration.
DIF: 2 REF: Page 19 OBJ: 1 | 6
5. How is the formula for population standard deviation () stated?
a. The positive square root of the mean ÷ sum of squared differences between mean
and individual values
b. Square root of the mean ÷ (N 1)
c. The positive square root of the [(sum of squared differences between mean and
individual values) ÷ N]
d. The sum of squared differences ÷ the positive square root of the mean
ANS: C
Standard deviation describes the dispersion (or variance) of values around a central point
(typically the mean). Variance is calculated by summing the squared differences between the
population mean and each individual sample value and dividing this sum by the population
size. This results in a large number, thus SD is the positive square root of this variance.
DIF: 1 REF: Page 10 OBJ: 1 | 11
6. Two types of error may be encountered during analysis of a substance. The type of error that
occurs with a constant or predictable difference or trend, either positive or negative, and thus
is related to bias, is a(n) error.
a. systematic
b. random
c. analytical
d. All of the above are correct.
ANS: A
Systematic error is a component of error, which in the course of a number of analyses of the
same measure and/or analyte remains constant or varies in a predictable (proportional) way.
This type of error will directly influence the mean value and affects bias.
DIF: 2 REF: Page 7 OBJ: 1 | 7
7. A research project examining cholesterol values using a new Cholestcheck assay produces the
following cholesterol values from a random sample of 14, 25-year-old women:
Mean = 137 mg/dL
2 standard deviations = 6 mg/dL
N = 14
The coefficient of variation percent for this assay is:
a. 1.14%.
b. 2.19%.
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
c. 4.38%.
d. 9.49%.
ANS: B
CV% is calculated by dividing a standard deviation by the mean and then multiplying that
value by 100%. In this case, one standard deviation is equal to 3 mg/dL (6 mg/dL ÷ 2), which
is divided by 137 and equals 0.02189. This value multiplied by 100% equals 2.189 or 2.19.
DIF: 2 REF: Page 20 OBJ: 11
8. You are performing a precision study on a new chemistry analyzer in your hospital lab by
analyzing a single sample many times. The study involves performing the analysis on
different shifts using different calibrators and analysis by different laboratorians. This aspect
of precision is referred to as:
a. repeatability.
b. reproducibility
c. validity.
d. reliability.
ANS: B
One aspect of precision is reproducibility, the closeness of agreement between results of
measurements performed under changed conditions of measurements (e.g., time, operators,
calibrators, and reagent lots).
DIF: 2 REF: Page 13 OBJ: 1 | 4
9. Following a precision study in which repeatability and reproducibility of 20 samples are
assessed, which one of the following formulae would be used to determine the total
standard deviation (2T)?
a. 2within-run/2 + 2between-run
b. (x2i x1i)
c. (x1 )2/N
d. 2within-run + 2 between-run
ANS: D
The degree of precision is usually expressed on the basis of statistical measures of
imprecision, such as the standard deviation. The total standard deviation (2T) may be split
into within-run and between-run components using the principle of analysis of variance
components (variance is the squared standard deviation):
2T = 2within-run + 2between-run
DIF: 2 REF: Page 13 OBJ: 4 | 11
10. The ability of an analytical method to assess small variations of the concentration of an
analyte, and that is often expressed as the slope of the calibration curve, is referred to as:
a. analytical specificity.
b. analytical sensitivity.
c. limit of detection.
d. analytical range.
ANS: B
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
Analytical sensitivity is the ability of an analytical method to assess small variations of the
concentration of analyte. This is often expressed as the slope of the calibration curve.
DIF: 1 REF: Page 6 OBJ: 1 | 4
11. Method selection involves consideration of several different criteria. Assessment of a
candidate method’s precision, accuracy, and analytical specificity are components of which
one of the following categories?
a. Analytical performance criteria
b. Medical criteria
c. Instrument parameters
d. Descriptive measures criteria
ANS: A
In evaluation of the performance characteristics of a candidate method, precision, accuracy
(trueness), analytical range, detection limit, and analytical specificity are of prime importance.
These are aspects of analytical performance criteria.
DIF: 1 REF: Page 7-8 OBJ: 2
12. The statistical analysis used to compare values obtained by a new method with those obtained
by an established method is:
a. a Student t test.
b. standard deviation.
c. regression analysis.
d. limit of detection.
ANS: C
Regression analysis is commonly applied when comparing the results of analytical method
comparisons. Typically an experiment is carried out in which a series of paired values is
collected when comparing a new method with an established method.
DIF: 1 REF: Page 20 OBJ: 1 | 5
13. The Student t distribution:
a. compares a sample mean to a population mean using the population.
b. compares the means of two samples using sample statistics.
c. assesses the means of samples prior to and following some intervention.
d. assesses the significance of difference between more than two variables.
ANS: B
A Student t distribution analysis is commonly used in significance tests, such as the
comparison of sample means. Therefore, if a random sample can be taken from a Gaussian
population, then the sample SD can be calculated from the sample means.
DIF: 2 REF: Page 11 OBJ: 1 | 3
14. A list of intervals followed by a list of frequencies is referred to as a:
a. frequency histogram.
b. range.
c. cumulative frequency distribution.
d. frequency distribution.
TEST BANK
Tietz Fundamentals of
Clinical Chemistry and Molecular Diagnostics
Carl A. Burtis, David E. Bruns
7th Edition
, Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition - Test Bank
Table of contents
I. PRINCIPLES OF LABORATORY MEDICINE
1. Clinical Chemistry, Molecular Diagnostics, and Laboratory Medicine
2. Selection and Analytical Evaluation of Methods — With Statistical Techniques
3. Clinical Evaluation of Methods
4. Evidence-Based Laboratory Medicine
5. Establishment and Use of Reference Values
6. Specimen Collection, Processing, and Other Preanalytical Variables
7. Quality Management
II. ANALYTICAL TECHNIQUES AND INSTRUMENTATION
8. Principles of Basic Techniques and Laboratory Safety
9. Optical Techniques
10. Electrochemistry and Chemical Sensors
11. Electrophoresis
12. Chromatography
13. Mass Spectrometry
14. Enzyme and Rate Analyses
15. Immunochemical Techniques
16 Automation
17. Point-of-Care Instrumentation
III. ANALYTES
18. Amino Acids, Peptides, and Proteins
19. Serum Enzymes
20. Tumor Markers and Cancer Genes
21. Kidney Function Tests — Creatinine, GFR, Urea, and Uric Acid
22. Carbohydrates
23. Lipids, Lipoproteins, Apolipoproteins, and Other Cardiac Risk Factors
24. Electrolytes and Blood Gases
25. Hormones
26. Catecholamines and Serotonin
27. Vitamins, Trace Elements, Nutritional Assessment
28. Hemoglobin, Iron, and Bilirubin
29. Porphyrins and Porphyrias
30. Therapeutic Drugs and Their Management
31. Clinical Toxicology
32. Toxic Metals
IV. PATHOPHYSIOLOGY
33. Diabetes
34. Cardiovascular Disease
35. Kidney Disease
36. Physiology and Disorders of Water, Electrolyte, and Acid-Base Metabolism
37. Liver Disease
38. Gastrointestinal and Pancreatic Diseases
39. Disorders of Bone and Mineral Metabolism
40. Disorders of the Pituitary Gland
41. Disorders of the Adrenal Cortex
42. Thyroid Disorders
43. Reproduction-Related Disorders
44. Pregnancy and Prenatal Testing
45. Newborn Screening and Inborn Errors of Metabolism
46. Pharmacogenetics
V. MOLECULAR DIAGNOSTICS NEW!
47. Principles of Molecular Biology
48. Nucleic Acid Techniques and Applications
49. Genomes and Nucleic Acid Alterations
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
Chapter 01: Clinical Chemistry, Molecular Diagnostics, and Laboratory MedicineTest
Bank
MULTIPLE CHOICE
1. An individual working in a clinical chemistry laboratory is married to a sales representative
who works for a company that sells chemistry laboratory supplies. When the laboratory
manager requests a list of needed supplies, cost of supplies, and vendors, this individual only
recommends the spouse’s company as the vendor. This is considered to be a(n):
a. accounting issue.
b. possible conflict of interest.
c. maintenance of confidentiality issue.
d. problem with resource allocation.
ANS: B
Concern has been raised over the interrelationships between practitioners in the medical field
and commercial suppliers of drugs, devices, equipment, etc., to the medical profession.
Similarly, relationships have been scrutinized between clinical laboratorians and
manufacturers and providers of diagnostic equipment and supplies. These concerns led the
National Institutes of Health (NIH) in 1995 to require official institutional review of financial
disclosure by researchers and management of situations in which disclosure indicates potential
conflicts of interest.
DIF: 1 REF: Page 4-5 OBJ: 6 | 7
2. A patient visits her physician stating that her prescribed painkiller is not working to reduce
the pain following her recent surgery. A friend of the patient claims that the same painkiller
“worked wonders” to reduce her pain after the same surgery. The physician states that the
difference in the effect of the drug might be caused by , which is studied in
pharmacogenetics.
a. epidemiology
b. an inherited disease
c. a conflict of interest
d. a genetic variation in drug-metabolizing enzymes
ANS: D
Pharmacogenetics is the study of the genetic variation of drug metabolism between
individuals.
DIF: 1 REF: Page 3 OBJ: 1
3. John works in a molecular diagnostics laboratory and receives a blood sample that has the
name of a close friend printed on the bar-coded label. The genetic test that is ordered on the
friend’s sample would provide diagnostic information about a disorder that has a poor
prognosis, and the test is usually performed by John. He asks a fellow employee to analyze
the sample for him and not divulge the results. This ethical issue concerns:
a. confidentiality of patient genetic and medical information.
b. a conflict of interest.
c. resource allocation.
d. diagnostic accuracy.
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
ANS: A
Clinical laboratorians have long been responsible for maintaining the confidentiality of all
laboratory results, a situation made even more critical with the advent of increasingly
powerful genetic testing.
DIF: 1 REF: Page 4 OBJ: 6 | 7
4. Molecular diagnostic testing methods and results can be:
a. qualitative only.
b. quantitative only.
c. either qualitative or quantitative.
ANS: C
Molecular diagnostic methods can be either qualitative or quantitative in nature, depending on
the clinical need.
DIF: 1 REF: Page 3 OBJ: 5
5. Clinical epidemiology, which is the study of the patterns, causes, and effects of health and
disease in certain populations, has provided the clinical laboratory with methods that evaluate
the effects and outcomes of laboratory testing. This allows for a more effective:
a. process of determining the cost of the testing methods.
b. selection and interpretation of laboratory tests.
c. determination of the boundaries between the components of the clinical lab.
d. conduct assessment.
ANS: A
Clinical epidemiologists have introduced methods to evaluate the effects and value of
laboratory testing in healthcare. These developments are expected to play an increasing role in
the selection and interpretation of laboratory tests.
DIF: 1 REF: Page 3 OBJ: 4
6. Analysis of which one of the following by molecular diagnostic methods provides a measure
of processes that are ongoing at the time of blood sampling?
a. Genetic variation in an individual’s response to a drug
b. Circulating plasma nucleic acids
c. Malignant lymphomas
d. Histocompatibility
ANS: B
Molecular diagnostics, given its very high sensitivity, has been applied to the study of plasma
nucleic acids (or circulating nucleic acids). Plasma nucleic acids analysis has been made
possible by the discovery that dying cells in the body release their DNA and RNA into the
extracellular compartment and ultimately into the bloodstream, where they can be detected
and analyzed. Given their short half-life in circulation (less than 24 hours), plasma nucleic
acids provide a measure of processes that are ongoing at the time of blood sampling.
DIF: 1 REF: Page 3 OBJ: 5
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
7. A healthy individual with no clinical signs or symptoms of disease visits his physician for a
routine physical examination. Blood samples are collected and sent to the laboratory. The tests
requested on the sample are for general laboratory analyses, including a complete blood count,
a panel of general chemistry tests (including glucose, protein, cholesterol, and others), and an
analysis of urine. This type of testing in laboratory medicine is directed at:
a. confirming a clinical suspicion of disease.
b. selecting a treatment for disease.
c. ruling in a diagnosis.
d. screening for disease in the absence of clinical signs or symptoms.
ANS: D
Testing in laboratory medicine may be directed at (1) confirming a clinical suspicion; (2)
making, or ruling in, a diagnosis; (3) excluding, or ruling out, a diagnosis;, (4) assisting in the
selection, optimization, and monitoring of treatment; (5) providing a prognosis; (6) screening
for disease in the absence of clinical signs or symptoms; or (7) establishing and monitoring
the severity of a physiologic disturbance. The field of laboratory medicine includes clinical
chemistry and areas such as microbiology and hematology. The general tests ordered on this
healthy individual are done to screen the physiologic systems despite the absence of any
symptoms.
DIF: 2 REF: Page 2 OBJ: 2
8. The discipline involved in the selection, provision, and interpretation of diagnostic testing that
uses primarily samples from patients is:
a. clinical chemistry.
b. hematology.
c. laboratory medicine.
d. molecular diagnostics.
ANS: C
The term “laboratory medicine” refers to the discipline involved in the (1) selection, (2)
provision, and (3) interpretation of diagnostic testing that uses primarily samples from
patients.
DIF: 1 REF: Page 1 OBJ: 1 | 3
9. A male laboratorian works in the clinical chemistry laboratory of a large hospital. He is
approached by his friend, who is a representative of a drug company, and asked to analyze
some patient samples for drug levels of a specific drug that the representative’s company sells
and that these patients use. The representative wants to publish a report on the rate of drug
absorption and distribution of this drug and tells his laboratorian friend that he will personally
reimburse him for his time. What ethical issues come into play here?
a. Resource allocation and conflict of interest
b. Maintenance of confidentiality and publishing issues
c. Maintenance of confidentiality, conflict of interest, and publishing issues.
d. Resource allocation, maintenance of confidentiality, conflict of interest, and
publishing issues.
ANS: D
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
Resource allocation, maintenance of confidentiality, conflict of interest, and publishing issues
are being compromised by the representative and the laboratorian if the laboratorian follows
through with the request. Using laboratory resources for a study that has not been approved by
the institutional review board is a resource allocation issue, revealing results of laboratory
tests is a confidentiality issue, receiving money to run laboratory tests from an individual with
a direct interest in the laboratory results is a conflict of interest, and publishing the results of
the testing would possibly be considered fraudulent and inappropriate.
DIF: 2 REF: Page 4-5 OBJ: 3 | 6 | 7
TRUE/FALSE
1. Molecular diagnostics testing is only used by the clinical chemistry laboratory.
ANS: F
The discipline of molecular diagnostics, which entered the realm of laboratory medicine in
multiple forms and in multiple fields, includes but is not limited to the study of hematopoietic
malignancies, such as malignant lymphomas and leukemias; the existence of nonhost nucleic
acids (microorganisms, graft-donor, fetal nucleic acids during pregnancy); and assessment of
solid tumors.
DIF: 1 REF: Page 3 OBJ: 1 | 5
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
Chapter 02: Selection and Analytical Evaluation of Methods—With Statistical
Techniques
MULTIPLE CHOICE
1. A statistic is a:
a. constant that describes some particular characteristic of a population.
b. value calculated from the observations in a sample to describe a particular
characteristic of that sample.
c. complete set of all observations that might occur as a result of performing a
particular procedure according to specified conditions.
d. graphic device for displaying a large set of data.
ANS: B
A statistic is a descriptive measure of a sample; it is a value calculated from the observations
in a sample to describe a particular characteristic of that sample.
DIF: 1 REF: Page 10 OBJ: 3
2. A population mean (µ) is calculated by which one of the following formulae?
a. xi/N
b. (b 1)/SE(b)
c. (x2i x1i)
d. (x1 )2/N
ANS: A
The parameter most commonly used to describe the central location of a population of N
values is the population mean ():
DIF: 1 REF: Page 10 OBJ: 3 | 11
3. Which one of the following is the correct formula for calculating the percent coefficient of
variation of a set of measurements?
a. CV = standard deviation 100%
b. CV = standard deviation ÷ 100%
c. CV = (standard deviation ÷ mean) 100%
d. CV = (mean + standard deviation) ÷ 100%
ANS: C
The coefficient of variation is the measure of relative imprecision. The value of CV% is
determined by calculating the ratio of the SD to the mean multiplied by 100%.
DIF: 1 REF: Page 10 OBJ: 11
4. The type of method comparison that compares the average results between two analyses with
the differences between varying concentration values of the two analyses is referred to as a(n):
a. Deming analysis.
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
b. linear regression plot.
c. ordinary least-squares plot.
d. Bland-Altman difference plot.
ANS: D
When comparing values obtained with two different methodologies, the average values of the
results are plotted against the differences between the values obtained from the two methods.
This examines the differences at varying analyte concentrations to determine whether a
problem exists at a certain concentration.
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5. How is the formula for population standard deviation () stated?
a. The positive square root of the mean ÷ sum of squared differences between mean
and individual values
b. Square root of the mean ÷ (N 1)
c. The positive square root of the [(sum of squared differences between mean and
individual values) ÷ N]
d. The sum of squared differences ÷ the positive square root of the mean
ANS: C
Standard deviation describes the dispersion (or variance) of values around a central point
(typically the mean). Variance is calculated by summing the squared differences between the
population mean and each individual sample value and dividing this sum by the population
size. This results in a large number, thus SD is the positive square root of this variance.
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6. Two types of error may be encountered during analysis of a substance. The type of error that
occurs with a constant or predictable difference or trend, either positive or negative, and thus
is related to bias, is a(n) error.
a. systematic
b. random
c. analytical
d. All of the above are correct.
ANS: A
Systematic error is a component of error, which in the course of a number of analyses of the
same measure and/or analyte remains constant or varies in a predictable (proportional) way.
This type of error will directly influence the mean value and affects bias.
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7. A research project examining cholesterol values using a new Cholestcheck assay produces the
following cholesterol values from a random sample of 14, 25-year-old women:
Mean = 137 mg/dL
2 standard deviations = 6 mg/dL
N = 14
The coefficient of variation percent for this assay is:
a. 1.14%.
b. 2.19%.
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
c. 4.38%.
d. 9.49%.
ANS: B
CV% is calculated by dividing a standard deviation by the mean and then multiplying that
value by 100%. In this case, one standard deviation is equal to 3 mg/dL (6 mg/dL ÷ 2), which
is divided by 137 and equals 0.02189. This value multiplied by 100% equals 2.189 or 2.19.
DIF: 2 REF: Page 20 OBJ: 11
8. You are performing a precision study on a new chemistry analyzer in your hospital lab by
analyzing a single sample many times. The study involves performing the analysis on
different shifts using different calibrators and analysis by different laboratorians. This aspect
of precision is referred to as:
a. repeatability.
b. reproducibility
c. validity.
d. reliability.
ANS: B
One aspect of precision is reproducibility, the closeness of agreement between results of
measurements performed under changed conditions of measurements (e.g., time, operators,
calibrators, and reagent lots).
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9. Following a precision study in which repeatability and reproducibility of 20 samples are
assessed, which one of the following formulae would be used to determine the total
standard deviation (2T)?
a. 2within-run/2 + 2between-run
b. (x2i x1i)
c. (x1 )2/N
d. 2within-run + 2 between-run
ANS: D
The degree of precision is usually expressed on the basis of statistical measures of
imprecision, such as the standard deviation. The total standard deviation (2T) may be split
into within-run and between-run components using the principle of analysis of variance
components (variance is the squared standard deviation):
2T = 2within-run + 2between-run
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10. The ability of an analytical method to assess small variations of the concentration of an
analyte, and that is often expressed as the slope of the calibration curve, is referred to as:
a. analytical specificity.
b. analytical sensitivity.
c. limit of detection.
d. analytical range.
ANS: B
, Test Bank - Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics 7th Edition (Burtis, 2015)
Analytical sensitivity is the ability of an analytical method to assess small variations of the
concentration of analyte. This is often expressed as the slope of the calibration curve.
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11. Method selection involves consideration of several different criteria. Assessment of a
candidate method’s precision, accuracy, and analytical specificity are components of which
one of the following categories?
a. Analytical performance criteria
b. Medical criteria
c. Instrument parameters
d. Descriptive measures criteria
ANS: A
In evaluation of the performance characteristics of a candidate method, precision, accuracy
(trueness), analytical range, detection limit, and analytical specificity are of prime importance.
These are aspects of analytical performance criteria.
DIF: 1 REF: Page 7-8 OBJ: 2
12. The statistical analysis used to compare values obtained by a new method with those obtained
by an established method is:
a. a Student t test.
b. standard deviation.
c. regression analysis.
d. limit of detection.
ANS: C
Regression analysis is commonly applied when comparing the results of analytical method
comparisons. Typically an experiment is carried out in which a series of paired values is
collected when comparing a new method with an established method.
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13. The Student t distribution:
a. compares a sample mean to a population mean using the population.
b. compares the means of two samples using sample statistics.
c. assesses the means of samples prior to and following some intervention.
d. assesses the significance of difference between more than two variables.
ANS: B
A Student t distribution analysis is commonly used in significance tests, such as the
comparison of sample means. Therefore, if a random sample can be taken from a Gaussian
population, then the sample SD can be calculated from the sample means.
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14. A list of intervals followed by a list of frequencies is referred to as a:
a. frequency histogram.
b. range.
c. cumulative frequency distribution.
d. frequency distribution.
