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MLAB 2360 Clinical I Page |1 Laboratory Quality Control Points: 55 Name:______________________ Date: ________________________ Part 1: 1 pt each 1. The main programs of the quality assurance department are: a. Risk management, in-service and continuing education, safety programs, quality control and peer review. b. Human resources, national laboratory week committee, and quality control documentation. c. Diversity, red ribbon week, and health and safety education. d. Laboratory operations, research and development. 2. Statistical methods commonly used to evaluate quality control data in the clinical lab is/are: a. T-test, z-test, and F-test. b. Numerical statistics and graphic techniques. c. Regression analysis and Pearson’s correlation coefficient d. X2 (chi-square) tests. 3. Precision of a method is best defined as: a. Agreement between replicate measurements obtained from the sample analyzed by the test method under prescribed conditions. b. Allowable bias. c. Accuracy. d. Closeness of the agreement between the result of the measurement and a true value of the measured 4. Systematic error causes: a. Shifts and trends on control (Levey Jennings) charts. b. Outliers on control charts. c. Random error. d. Imprecision. 5. Select one example of the postanalytic phase: a. Specimen preparation b. Specimen analysis c. Clinician receives the test result d. Specimen collection MLAB 2360 Clinical I Page |2 Part 2: 2pts each For each of the following Levey-Jennings charts, circle the choice “acceptable” or “out of control”. For each that is “out of control”, tell Westgard rule is violated and the first day that QC must be rejected. NOTE: There may be more than one “out of control” problem for each chart. Use the rules Westgard rules given in the QC powerpoint (Shift, Trend, 13s, 22s, R4s, 41s). Example: Levey-Jennings Control Chart 100 +3SD +2SD +1SD Mean 95 90 -1SD -2SD -3SD 85 80 1 3 5 7 9 11 13 Days or Runs On all of the Levey Jennings charts in this exercise: Mean is 90 and the Control range is 85-95** **Control Range= ±2SD which represents the 95% confidence interval** Acceptable Out of Control If unacceptable (out of control), Explanation: This chart shows a trend (6 consecutive points dropping or rising) from days 3 through 8, so the results are out of control on day 8. MLAB 2360 Clinical I Page |3 QC Levey-Jennings Chart 1: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 11 13 Days or Runs 1. Acceptable Out of Control If unacceptable, Explanation: QC Levey-Jennings Chart 2: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 Days or Runs 2. Acceptable Out of Control If unacceptable, Explanation: 11 13 MLAB 2360 Clinical I Page |4 QC Levey-Jennings Chart 3: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 11 13 Days or Runs 3. Acceptable Out of Control If unacceptable, Explanation: QC Levey-Jennings Chart 4: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 Days or Runs 4. Acceptable Out of Control 11 13 MLAB 2360 Clinical I Page |5 If unacceptable, Explanation: QC Levey-Jennings Chart 5: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 11 13 Days or Runs 5. Acceptable Out of Control If unacceptable, Explanation: QC Levey-Jennings Chart 6: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 Days or Runs 6. Acceptable Out of Control 11 13 MLAB 2360 Clinical I Page |6 If unacceptable, Explanation: QC Levey-Jennings Chart 7: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 11 13 Days or Runs 7. Acceptable Out of Control If unacceptable, Explanation: QC Levey-Jennings Chart 8: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 Days or Runs 8. Acceptable Out of Control If unacceptable, Explanation: 11 13 MLAB 2360 Clinical I Page |7 QC Levey-Jennings Chart 9: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 11 13 Days or Runs 9. Acceptable Out of Control If unacceptable, Explanation: QC Levey-Jennings Chart 10: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 Days or Runs 10. Acceptable Out of Control 11 13 MLAB 2360 Clinical I Page |8 If unacceptable, Explanation: QC Levey-Jennings Chart 11: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 11 13 Days or Runs 11. Acceptable Out of Control If unacceptable, Explanation: QC Levey-Jennings Chart 12: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 Days or Runs 12. Acceptable Out of Control 11 13 MLAB 2360 Clinical I Page |9 If unacceptable, Explanation: QC Levey-Jennings Chart 13: Levey-Jennings Control Chart 100 95 Mean = 90 Control 90 Range = 85-95 85 80 1 3 5 7 9 11 13 Days or Runs 13. Acceptable Out of Control If unacceptable, Explanation: Part 3: 2pts each 1. Calculate the mean of the following set of numbers, SHOW YOUR WORK: 25,22,26,24,21,29,26,20,28,23 Mean:____________ 2. Calculate the variance from the above values, SHOW YOUR WORK. X 25 22 26 24 21 29 26 20 28 23 (X - Mean)2 X - Mean TOTAL MLAB 2360 Clinical I P a g e | 10 Variance:____________ 3. Calculate the standard deviation from the above values, SHOW YOUR WORK. 4. Calculate the mean of the following values, SHOW YOUR WORK: 82,85,90,86,91,90,81,86,94,89. Mean: ___________ 5. Calculate the variance from the above values (question 4), SHOW YOUR WORK. X 82 85 90 86 91 90 81 86 94 89 (X - Mean)2 X - Mean TOTAL Variance:______________ 6. Calculate the standard deviation from the above values, SHOW YOUR WORK. MLAB 2360 Clinical I P a g e | 11 Part 4: 3 pts each 1. Your lab manager asks you to create the new control range for the new lot of hematology control level 1. The following 20 hemoglobin values are gathered to determine the control limits. Using a calculator or website SD function, calculate and record the mean, the standard deviation, and the 95% confidence interval for this set of values. 4.2 4.7 4.3 4.4 4.0 4.9 4.7 4.6 4.7 4.9 5.0 4.1 4.2 4.7 Mean:__________ 1 SD:__________ 4.6 4.0 4.4 4.5 4.8 4.4 95% Confidence range:________________ 2. Given the results above, label the following Levey-Jennings Control chart with all of the following: Mean Values for -3SD, -2SD, -1SD, +1SD, +2SD, +3SD Result in mg/dL Control 1 Hemoglobin Levey-Jennings chart AUGUST 1 2 3 4 5 6 7 8 9 10…… Day . MLAB 2360 Clinical I P a g e | 12 3. You have your Levey-Jennings Control chart ready. Your supervisor tells you to begin using the lot. Record the first 10 days of Control 1 Hemoglobin results. In your lab, you run controls once per day because you are a clinic open from 8-5pm. Plot each data point on your labeled chart and circle whether the controls are acceptable or “out.” DAY of August 1= 4.5 mg/dl 2=4.2 mg/dl 3=4.1 mg/dl 4=4.6 mg/dl 5=4.7 mg/dl ACCEPTABLE 6=4.8 mg/dl 7=4.4 mg/dl 8=4.4 mg/dl 9=4.2 mg/dl 10=4.9 mg/dl OUT OF CONTROL 4. You run a normal serum glucose control and obtain a value of 78.4 mg/dL. The mean for this control is 74.8 mg/dL and 1 SD has been calculated as 1.2. Is the value of 78.4 within 2SD (95% confidence interval)? Circle the correct answer. YES NO