USCIS Quality Control & Assurance 2 — Questions and Answers
Question 1: What is the primary purpose of running a control serum alongside patient samples in a USCIS civil surgeon laboratory test?
- To reduce the cost of testing
- To verify that the assay is performing within acceptable limits (Correct answer)
- To satisfy insurance billing requirements
- To increase the throughput of the analyzer
Correct answer: To verify that the assay is performing within acceptable limits
Control sera are run to confirm the assay is functioning correctly before patient results are reported.
Question 2: A civil surgeon's lab uses a commercial TB IGRA kit. The kit insert states results are invalid if the positive control OD is below 0.8. The run shows a positive control OD of 0.6. What is the correct action?
- Report all patient results as indeterminate
- Report results normally since OD difference is small
- Repeat the entire run with a new kit lot or after troubleshooting (Correct answer)
- Accept results for negative patients only
Correct answer: Repeat the entire run with a new kit lot or after troubleshooting
A failed positive control invalidates the entire run; the test must be repeated after identifying the cause.
Question 3: Which document typically defines the acceptable range for a laboratory's quality control results?
- The patient's immigration petition
- The laboratory's standard operating procedure (SOP) (Correct answer)
- The civil surgeon's personal notes
- The local health department annual report
Correct answer: The laboratory's standard operating procedure (SOP)
SOPs specify control ranges, corrective actions, and documentation requirements for each test.
Question 4: When reviewing syphilis screening results for I-693 purposes, a civil surgeon notices the RPR titer has doubled from the previous visit. What does this suggest?
- The test was a false positive
- There may be active or reinfection with syphilis (Correct answer)
- The laboratory made a clerical error
- The result is within normal biological variation
Correct answer: There may be active or reinfection with syphilis
A fourfold (two-dilution) rise in RPR titer generally indicates active infection or reinfection.
Question 5: A clinic performing I-693 examinations discovers that refrigerated vaccine vials were stored at 10°C instead of the required 2–8°C. What quality assurance step must occur?
- Continue use since the temperature is close enough
- Document the excursion and contact the manufacturer or public health authority for guidance (Correct answer)
- Discard only vials stored more than 24 hours at that temperature
- Administer the vaccines immediately to avoid further loss
Correct answer: Document the excursion and contact the manufacturer or public health authority for guidance
Temperature excursions must be documented and the manufacturer or health authority consulted to determine vaccine viability.
Question 6: What Westgard rule is violated when two consecutive control values fall more than 2 standard deviations from the mean on the same side?
- 1-2s warning rule
- 2-2s rule (Correct answer)
- R-4s rule
- 10-x rule
Correct answer: 2-2s rule
The 2-2s rule is triggered when two consecutive controls exceed ±2 SD on the same side, indicating systematic error.
Question 7: For USCIS I-693 purposes, which of the following best describes the role of proficiency testing (PT) in a civil surgeon's laboratory?
- PT is optional and only performed at the physician's discretion
- PT is an external quality assessment that verifies the lab produces accurate results compared to peer labs (Correct answer)
- PT replaces the need for daily internal quality controls
- PT is performed only when a new technician joins the laboratory
Correct answer: PT is an external quality assessment that verifies the lab produces accurate results compared to peer labs
Proficiency testing through external programs provides objective evidence that a laboratory's results are accurate and comparable to peers.
USCIS Quality Control & Assurance 2
What is the primary purpose of running a control serum alongside patient samples in a USCIS civil surgeon laboratory test?