ASCP: Lab operations Study Guide
Exam Fully Solved.
Quality assessment or quality assurance - Answer Process by which lab ensures quality
results by closely monitoring preanalytical, analytical, and postanalytical stages of testing
Preanalytical QA - Answer Everything that precedes test performance, e.g., test ordering,
patient preparation, patient ID, specimen collection, specimen transport, specimen processing.
Analytical QA - Answer Everything related to assay, e.g., test analysis, QC, reagents,
calibration, preventive maintenance.
Postanalytical QA - Answer Everything that comes after test analysis, e.g., verification of
calculations & reference ranges, review of results, notification of critical values, result reporting,
test interpretation by physician, follow-up patient care.
Quality system - Answer All the lab's policies, processes, procedures, and resources needed
to achieve quality testing
Quality control - Answer Part of analytical phase of quality assurance; process of monitoring
results from control samples to verify accuracy of patient results
Control - Answer Sample that is chemically & physically similar to unknown specimen & is
tested in exactly the same manner. Monitors precision of test system. For nonwaived
quantitative tests, CLIA requires at least 2 levels of controls each day test is performed. For
qualitative tests, pos & neg controls must be included with each run.
External QC - Answer Testing control material not built into test system. Term also used for
QC that extends beyond lab, e.g., participation in proficiency testing program.
Internal monitoring systems - Answer Electronic, internal, or procedural controls that are
built into test system
Equivalent QC - Answer Labs may reduce frequency of testing external QC materials for
certain test systems if they can demonstrate through a CMS-approved QC evaluation process
that test system is stable
Standard deviation - Answer √(∑(mean-individual value)^2/(number of values- 1)
, Coefficient of variation - Answer (SD/mean)x100. Less = more precision
1 SD Gaussian - Answer 68%
2 SD Gaussian - Answer 95%
3 SD Gaussian - Answer 99.7%
Control limits - Answer plus/minus 2SD
Outlier - Answer Control result outside established limits. May be due to chance or may
indicate problem in test system. If it occurs more than once in 20 successive runs, investigation
must be carried out
Shift - Answer 6 consecutive control values on same side of mean
Trend - Answer Control values increasing or decreasing for 6 consecutive runs
Error, random - Answer Error that doesn't recur in regular pattern, e.g., error due to dirty
glassware, use of wrong pipet, voltage fluctuation, sampling error, anticoagulant or drug
interference. Indicated by control value significantly different from others on Levey-Jennings
chart, or violation of the 13S or R4S Westgard rules. Usually a 1-time error, & controls &
samples can be rerun with success.
Error, systematic - Answer Recurring error inherent in test procedure, e.g., dirty photometer,
faulty ISE, evaporation or contamination of standards or reagents. Affects all results. Indicated
by trend or shift on Levey-Jennings chart, or violation of 22S , 41S , or 10 × Westgard rules.
Requires investigation to determine cause.
False rejection - Answer Rejection of run because QC results indicate problem when none is
present. Use of Westgard rules minimizes false rejections.
1 2s - Answer 1 control >±2s from mean. Warning flag of possible change in accuracy or
precision. Initiates testing of other rules. If no violation of other rules, run is considered in
control
1 3s - Answer 1 control >±3s from mean. *Random*. Rejection rule
Exam Fully Solved.
Quality assessment or quality assurance - Answer Process by which lab ensures quality
results by closely monitoring preanalytical, analytical, and postanalytical stages of testing
Preanalytical QA - Answer Everything that precedes test performance, e.g., test ordering,
patient preparation, patient ID, specimen collection, specimen transport, specimen processing.
Analytical QA - Answer Everything related to assay, e.g., test analysis, QC, reagents,
calibration, preventive maintenance.
Postanalytical QA - Answer Everything that comes after test analysis, e.g., verification of
calculations & reference ranges, review of results, notification of critical values, result reporting,
test interpretation by physician, follow-up patient care.
Quality system - Answer All the lab's policies, processes, procedures, and resources needed
to achieve quality testing
Quality control - Answer Part of analytical phase of quality assurance; process of monitoring
results from control samples to verify accuracy of patient results
Control - Answer Sample that is chemically & physically similar to unknown specimen & is
tested in exactly the same manner. Monitors precision of test system. For nonwaived
quantitative tests, CLIA requires at least 2 levels of controls each day test is performed. For
qualitative tests, pos & neg controls must be included with each run.
External QC - Answer Testing control material not built into test system. Term also used for
QC that extends beyond lab, e.g., participation in proficiency testing program.
Internal monitoring systems - Answer Electronic, internal, or procedural controls that are
built into test system
Equivalent QC - Answer Labs may reduce frequency of testing external QC materials for
certain test systems if they can demonstrate through a CMS-approved QC evaluation process
that test system is stable
Standard deviation - Answer √(∑(mean-individual value)^2/(number of values- 1)
, Coefficient of variation - Answer (SD/mean)x100. Less = more precision
1 SD Gaussian - Answer 68%
2 SD Gaussian - Answer 95%
3 SD Gaussian - Answer 99.7%
Control limits - Answer plus/minus 2SD
Outlier - Answer Control result outside established limits. May be due to chance or may
indicate problem in test system. If it occurs more than once in 20 successive runs, investigation
must be carried out
Shift - Answer 6 consecutive control values on same side of mean
Trend - Answer Control values increasing or decreasing for 6 consecutive runs
Error, random - Answer Error that doesn't recur in regular pattern, e.g., error due to dirty
glassware, use of wrong pipet, voltage fluctuation, sampling error, anticoagulant or drug
interference. Indicated by control value significantly different from others on Levey-Jennings
chart, or violation of the 13S or R4S Westgard rules. Usually a 1-time error, & controls &
samples can be rerun with success.
Error, systematic - Answer Recurring error inherent in test procedure, e.g., dirty photometer,
faulty ISE, evaporation or contamination of standards or reagents. Affects all results. Indicated
by trend or shift on Levey-Jennings chart, or violation of 22S , 41S , or 10 × Westgard rules.
Requires investigation to determine cause.
False rejection - Answer Rejection of run because QC results indicate problem when none is
present. Use of Westgard rules minimizes false rejections.
1 2s - Answer 1 control >±2s from mean. Warning flag of possible change in accuracy or
precision. Initiates testing of other rules. If no violation of other rules, run is considered in
control
1 3s - Answer 1 control >±3s from mean. *Random*. Rejection rule
