TB Test Quality Assurance and Improvement 2 — Questions and Answers
Question 1: A TB testing clinic notices a 15% rate of indeterminate TST results over the past month. What is the BEST first step in a quality improvement process?
- Retrain all staff on proper intradermal injection technique (Correct answer)
- Purchase new tuberculin syringes from a different supplier
- Discontinue TST and switch entirely to IGRA testing
- Report the issue to the state health department immediately
Correct answer: Retrain all staff on proper intradermal injection technique
High indeterminate or invalid TST results most often stem from improper intradermal technique, making staff retraining the primary corrective action.
Question 2: Which metric is MOST useful for monitoring the quality of tuberculin skin test (TST) administration over time?
- Rate of documented Mantoux technique errors per 100 tests (Correct answer)
- Total number of positive TST results per month
- Average time from application to reading
- Number of patients who refuse TST
Correct answer: Rate of documented Mantoux technique errors per 100 tests
Tracking documented technique errors per 100 tests directly measures administration quality and identifies trends requiring correction.
Question 3: A quality audit finds that TST readings are being documented as positive at 8 mm when the CDC threshold for an immunocompromised patient is 5 mm. This represents a:
- False negative documentation error (Correct answer)
- False positive documentation error
- Technique administration error
- Specimen handling error
Correct answer: False negative documentation error
Recording 8 mm as positive for a patient whose threshold is 5 mm means true positives at 5–7 mm are being incorrectly classified as negative—a false negative error.
Question 4: Which component of a Plan-Do-Study-Act (PDSA) cycle involves collecting baseline data before implementing a change in TB testing workflow?
- Plan (Correct answer)
- Do
- Study
- Act
Correct answer: Plan
The Plan phase includes identifying the problem, setting objectives, and collecting baseline data to measure improvement against.
Question 5: A TB clinic wants to reduce patient wait times between TST placement and reading. Which quality tool BEST maps the steps in the current process to identify delays?
- Process flow diagram (flowchart) (Correct answer)
- Pareto chart
- Control chart
- Fishbone diagram
Correct answer: Process flow diagram (flowchart)
A process flowchart visually maps each step in a workflow, making it easy to identify bottlenecks and unnecessary delays.
Question 6: During a QA review, it is found that 20% of IGRA blood specimens arrive at the laboratory beyond the 16-hour incubation window. The MOST appropriate corrective action is:
- Establish a specimen transport protocol with time-stamp checkpoints (Correct answer)
- Reject all specimens and retest all patients immediately
- Switch all testing to TST to avoid transport issues
- Increase the acceptable incubation window to 24 hours
Correct answer: Establish a specimen transport protocol with time-stamp checkpoints
A formal transport protocol with documented time-stamps addresses the root cause of delayed processing and ensures specimens meet validity criteria.
Question 7: A QA coordinator wants to determine which TB testing errors occur most frequently in order to prioritize corrective actions. The BEST tool to use is:
- Pareto chart (Correct answer)
- Scatter diagram
- Run chart
- Cause-and-effect diagram
Correct answer: Pareto chart
A Pareto chart ranks errors by frequency, helping teams focus on the 20% of causes responsible for 80% of problems.
TB Test Quality Assurance and Improvement 2
A TB testing clinic notices a 15% rate of indeterminate TST results over the past month.
What is the BEST first step in a quality improvement process?