QC 101

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Cards (53)

  • What is Laboratory Quality?
    Accuracy, reliability, and timeliness. Lab results must be accurate as possible.
  • What is quality assurance?
    QA in the lab is all the things we do to ensure quality results.
  • ISO Document that applies to the medical Lab is ISO 15189
  • The Lab:
    Organization, Customer Focus, Facilities and safety, Personnel, Purchasing and Inventory, Equipment.
  • The Work:
    Process Management, Documents and records, Information management.
  • Performance:
    Nonconformance Management, Assessments, Continual Improvement. (Reflecting on self performance).
  • Pre-analytic
    Test order, sample collection, transport, receipt and process
  • Analytic
    Testing
  • Post-analytic
    reporting, sample archiving
  • Sensitivity
    Measures low amount of component, few false negatives if high sensitivity, Positive controls in low amounts.
  • Specificity
    Specific- measures one component only, no false positives, uses negative controls.
  • Report sent to wrong location
    Post-analytical
  • QC not within range
    Analytical
  • Mislabeled specimen
    Pre-analytical
  • CV= SD/ Mean divided by 100
    Always to 1 decimal place and in percent
  • Precision
    reproducibility of a result. Ex hitting the same spot on the target.
  • Accuracy
    The correctness. Ex. hitting the center of the target.
  • Systemic error
    Change in accuracy, affect all results until the error is fixed.
  • Random error
    Change in precision, no prediction, one off.
  • Population
    large body of data- should be random and represent any part of the population.
  • Calibrator
    Similar to standard, has more than one analyte, used to correct analytical procedure.
  • Standard
    A solution having known concentration of a single analyte.
  • Control
    A solution that contains the same constituents as those being analyzed in the patient sample. Used to test if our analytical system is giving accurate results or not.
  • The lower the CV the more precise.
  • Acceptable CV
    Manual methods= less than or equal to 10.0%
    Instrumental methods= less than 3.0%
  • Normal Distribution
    1SD- 68%
    2SD- 95%
    3SD- 99.7%
  • Reference Range
    Range of results for clinically healthy people.
  • Control range
    The acceptable range of a known control sample for an analyte in order to monitor the precision and accuracy of our analytical system.
  • New lot # means calibration time
  • Quantitative analysis
    The control is a sample that has known values. Used for accuracy and precision.
  • Qualitative analysis

    Provide positive vs negative or reactive vs non-reactive. Known as screening tests- Ex. covid or pregnancy test.
  • 1 in 20 control values may fall outside of the 2SD range.
  • Trend
    Gradual loss of reliability. Usually subtle. Deterioration.
  • Shift
    Abrupt change, a sudden or dramatic positive or negative change.
  • Always run QC after calibration
  • Linearity range
    If a sample is above linearity range or too high to be run on the analyzer, it can be diluted.
  • Linearity (dynamic range)
    The limit of what the analyzer can detect on a test.