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Hematology

Individualized Quality Control Plan

For decades, Quality Control (QC) in the clinical laboratory followed a “one-size-fits-all” regulatory model: run two levels of external liquid controls every 24 hours. However, this rigid schedule did not account for the advanced internal monitoring capabilities of modern instrumentation or the specific risks inherent to different test environments. In 2016, the Centers for Medicare & Medicaid Services (CMS) introduced the Individualized Quality Control Plan (IQCP) as a voluntary alternative QC option under CLIA. IQCP allows laboratories to customize their QC frequency based on a scientifically robust Risk Assessment of their specific testing process

The Structure of IQCP

An IQCP is not just a decision to run less QC; it is a formal, documented program that must be approved by the Laboratory Director. It consists of three mandatory components: Risk Assessment (RA), Quality Control Plan (QCP), and Quality Assessment (QA)

Risk Assessment (RA)

This is the investigative phase. The laboratory must identify and evaluate all potential sources of error in the entire testing phase (Pre-analytical, Analytical, Post-analytical). The laboratory must evaluate risks in five specific areas (The “5 M’s”):

  1. Specimen: What if the sample is clotted? What if it is short (low volume)? What if it is lipemic?
  2. Test System: What if the laser fails? What if the temperature fluctuates? Does the machine have internal electronic checks?
  3. Reagent: What if the reagent expires? What if the lot number changes? What if the shipment was left on the loading dock in the heat?
  4. Environment: Does the lab have stable power? Is there excessive vibration? Is the humidity controlled?
  5. Testing Personnel: Are staff properly trained? Is competency assessed? Is there high turnover?
  • Risk Evaluation Matrix: For each identified risk, the lab assigns a score based on:
    • Frequency of Occurrence: How often does this happen? (Rare \(\rightarrow\) Frequent)
    • Severity of Harm: If this error happens, will it hurt the patient? (Negligible \(\rightarrow\) Critical)
    • Result: High-risk items (Frequent + Critical) require strict mitigation (e.g., more QC). Low-risk items (Rare + Negligible) may be managed by the instrument’s internal checks

Quality Control Plan (QCP)

Based on the findings of the Risk Assessment, the laboratory creates the actual plan. The QCP defines the type, number, and frequency of control procedures required to reduce the identified risks to an acceptable level

  • Minimum Requirement: The QCP cannot be less stringent than the manufacturer’s instructions. If the package insert says “Run QC daily,” you must run QC daily, regardless of IQCP. IQCP is primarily used to reduce QC frequency for unit-use devices (e.g., POCT kits) or to justify electronic QC over liquid QC
  • Mitigation Strategies: The QCP lists the controls used to mitigate the risks
    • Risk: Reagent deterioration. Mitigation: Daily liquid QC
    • Risk: Electronic drift. Mitigation: Internal electronic checks (System Check) performed automatically every 30 minutes
    • Risk: Operator error. Mitigation: Barcode lockout preventing unauthorized users

Quality Assessment (QA)

This is the ongoing monitoring phase. The laboratory cannot simply write the plan and forget it. They must continuously monitor the data to ensure the IQCP is actually working (i.e., that errors are not slipping through)

  • Monitoring Metrics
    • Reviewing QC logs monthly
    • Tracking Proficiency Testing (PT) failures
    • Monitoring physician complaints
    • Reviewing instrument error logs
  • Corrective Action: If the lab notices an increase in errors (e.g., a Proficiency Testing failure occurred on a day when liquid QC was not run), the IQCP must be re-evaluated. The lab may be forced to return to the default CLIA regulations (daily QC) until the problem is solved

IQCP Applications in Hematology

While automated Hematology analyzers generally require daily liquid QC (commercial controls) due to the complexity of counting particles, IQCP is heavily utilized in Point-of-Care Testing (POCT) and Coagulation

Point-of-Care Coagulation (ACT & INR)

  • The Problem: Running two levels of liquid QC on every single cartridge (unit-use device) is prohibitively expensive and time-consuming
  • The IQCP Solution
    • Risk Assessment: Determines that the cartridges have internal checks (a “fail-safe” mechanism) and the instrument performs electronic QC on every power-up
    • QCP: The lab may decide to run Liquid QC only once per shipment: (or new lot number) and rely on the Internal Electronic QC for daily monitoring. This saves thousands of dollars in control material while maintaining quality

Manual Kit Tests (e.g., Sickle Solubility)

  • The Problem: CLIA requires positive and negative controls each day of use. If the test is rarely ordered, this wastes reagents
  • The IQCP Solution: The lab assesses the stability of the reagents and the simplicity of the test. The QCP might specify running external controls only once per week or with each new lot, rather than daily, provided the internal procedural controls are documented with every patient

Electronic Quality Control (EQC)

A major component of IQCP is the reliance on Electronic QC. Modern instruments perform self-diagnostics that mimic the signal of a patient sample

  • Simulator: A physical device (e.g., an optical filter or an electronic dongle) inserted into the machine that produces a known signal
  • Internal Circuitry: The software checks the voltage and current of the detectors
  • Justification: In the Risk Assessment, the lab must provide data from the manufacturer proving that this Electronic QC is capable of detecting the same failures that liquid QC would detect (e.g., optical alignment drift)

Limitations & Compliance

  • Director Responsibility: The Laboratory Director (Pathologist/PhD) must sign the IQCP. They bear the ultimate liability. If a patient is harmed because QC was not run, the Director is responsible for the adequacy of the IQCP
  • Exceptions: IQCP cannot be used for:
    • Pathology/Histology (which has its own QC rules)
    • Tests where the manufacturer explicitly mandates daily external QC
  • Inspections: During a CAP or Joint Commission inspection, the surveyor will heavily scrutinize the Risk Assessment. They will ask, “Show me the data that convinced you it was safe to drop QC to once a week.” If the data is missing or weak, the IQCP will be rejected, and the lab will be cited for Failure of QC