Beyond QC: Building a Stronger Quality Ecosystem in Your Lab

If you've been in the clinical lab long enough, you know that running two levels of QC every day your analyzers are in use is table stakes. It's the baseline. But here's the thing, QC alone doesn't tell the whole story. There's an entire ecosystem of quality tools surrounding routine QC, and knowing how to use them can make your lab more resilient, more compliant, and frankly, less stressful to manage.

In a recent webinar, Dr. Alec Saitman walked through four of these tools: individualized quality control plans (IQCPs), patient-based quality monitoring, lot-to-lot verifications, and proficiency testing best practices. Here's a breakdown of what he covered and why it matters for your lab.

IQCPs: Not a Shortcut, But a Structured Alternative

Let's get this out of the way first: an IQCP is not a way to skip QC. It's a highly structured, documentation-heavy framework that allows specific types of testing to operate under an alternative QC schedule, one that may not require running two levels of external QC every single day patients are tested.

The path to IQCP eligibility is narrower than many labs assume. Among the key hurdles: your state has to allow them, the test can't be waived or anatomic/cytopathology, and the instrument must have some form of internal quality control built in. Only a small slice of clinical testing will ever qualify.

If a test does qualify, an IQCP has three core components:

• Risk Assessment — What could go wrong if you're not running traditional QC daily? You have to evaluate pre-analytic, analytic, and post-analytic risks and decide whether the level of risk is acceptable.

• Quality Control Plan — This is the meat of it. What are you going to do instead? Define QC type, frequency, and acceptance criteria with specificity.

• Quality Assessment — Ongoing monitoring to make sure the plan is actually working. This is emphatically not a "set it and forget it" process.

The bottom line on IQCPs is if you're considering one, go in with eyes open. They can be appropriate in the right circumstances, but they require significant effort to build and maintain, and for good reason. You're assuming real risk by stepping away from daily QC.

Patient Moving Averages and Medians: QC's Under-Utilized Sidekick

Here's a question worth sitting with: if your QC looked fine yesterday morning, would you know if something drifted by yesterday afternoon?

That's the gap that patient-based quality monitoring is designed to address. Rather than waiting for the next scheduled QC run, you're using your actual patient results, aggregated into sets and calculated as either a mean or median, to continuously monitor assay performance in real time.

A few things to know about how these work:

Moving averages (means) work best for stable analytes with symmetric distributions, like sodium, potassium, and calcium. Since extreme values can skew the average, truncation limits are used to exclude outliers from the calculation. Medians, on the other hand, naturally handle skewed distributions and are a better fit for analytes like enzymes (think AST, where one patient with significant liver disease can throw off a mean dramatically).

The payoff? For high-volume tests, you might generate dozens or even hundreds of data points in the same time window where traditional QC gives you two. You're also working with a real patient matrix, not a reconstituted surrogate, which makes this type of monitoring particularly sensitive to calibration drift and reagent lot shifts.

And no, moving averages and medians do not replace traditional QC. That's worth saying clearly. They supplement it. You still run your two levels. But used well, they can give you an earlier warning system that helps you catch problems before they become corrections.

One practical note from Dr. Saitman: you don't have to implement patient monitoring for every analyte on your analyzer. Pick the ones that tend to drift or cause headaches. (Calcium, anyone?)

Lot-to-Lot Verifications: A Critical Control Point You Can't Skip

Changing reagent lots is routine. But what happens when that new lot performs a little differently than the last one? If you don't find out before you start reporting patient results, you may end up chasing corrections rather than preventing them.

Lot-to-lot verification is the process of comparing your current reagent lot to the incoming one using actual patient specimens run in parallel on both lots. The goal is to detect analytical shifts, systematic differences in how the new lot performs, before they affect patient care.

Here's how a practical verification approach looks:

• Use at least 5 patient specimens that span the analytical measurement range (and document why if you can't hit that number)

• Run QC materials in parallel as well — sometimes QC is affected, sometimes only patients are, and sometimes neither or both

• Calculate percent bias between lots and compare to your defined total allowable error (TAE) for each analyte

• Pass or fail the lot based on criteria you've established before you start the process, not improvised on the spot

That last point is worth emphasizing. CAP, the Joint Commission, and COLA all expect defined acceptance criteria for lot verifications. Not having them documented in advance is a gap. Build a policy, reference consensus-based TAE guidelines, and apply them consistently.

One tip that's easy to overlook: buying reagents in larger lot quantities means fewer lot-to-lot verifications over time. If you have analytes that tend to be variable between lots, this can be a meaningful way to reduce that burden.

Proficiency Testing: Your Best Measure of Real-World Accuracy

Proficiency testing (PT) is, as Dr. Saitman put it, "the grandmother of QC." It's an external quality assessment — blind specimens from a CMS-approved PT provider, tested the same way you'd test a patient sample, with results submitted and evaluated against your peer group.

A few basics worth revisiting:

Labs performing non-waived testing must enroll in a CMS-approved PT program for regulated analytes. (CMS publishes the regulated analyte list openly; it's not hidden.) For unregulated analytes, you still need an accuracy assessment, and the path of least resistance is to enroll voluntarily in your PT provider's program for those tests, if one exists.

Peer group selection matters enormously. This is one of the most common sources of PT failure, and it's entirely preventable. If you're not 100% sure which peer group matches your method, reagents, and analyzer, call your PT provider before you submit. That five-minute conversation can save hours of troubleshooting down the road.

When a PT result does come back as a failure, the investigation process matters just as much as the result. Dr. Saitman’s recommended approach:

1. Start with the basics: Did you select the right PT provider, peer group, and units? Was there a transcription error? A decimal point in the wrong place?

2. Check specimen handling. Was the PT processed exactly like a patient sample? Were there any deviations, documented or otherwise?

3. Look at QC data from two weeks before and after the PT event. Were there any subtle shifts or trends building?

4. Review recent lot changes or maintenance events. The closer they are to the PT event, the more suspect they are.

5. Ask whether all PT results failed or just one. A pattern of all-high or all-low is a stronger signal of a systematic issue than a single outlier.

And don't discard your PT materials. Stored PT specimens have real value — for repeat testing after a failure, for validations, for lot-to-lot work. They're expensive and useful. Keep them.

Putting It All Together

Routine QC is the anchor of your quality program, but it's not the whole picture. IQCPs, patient-based monitoring, lot verifications, and proficiency testing each provide something that the others can't. Together, they create a quality ecosystem that's more sensitive, more defensible, and better positioned to protect your patients and your lab.

The common thread across all of these tools? Documentation. Document your risk assessments. Document your lot-to-lot results. Document your PT investigation. Document every deviation from normal workflow and why. If it's not written down, it didn't happen, and that matters when an inspector is in the building.

Want to go deeper on any of these topics? Dr. Saitman’s webinar series continues with sessions on competency assessment and training, and AI tools for working smarter in the clinical lab. If you have the MediaLab by Vastian Compliance and CE library, look for the Live Webinar tag in the lab management category to access recordings and earn CE credit.

If you're ready for a more resilient quality program, we're ready to show you how.

→ Explore the MediaLab by Vastian Lab QMS Platform

‍