Decision-Based Learning

Laboratory Quality Systems

From Quality Control to Clinical Decision Integrity

An advanced training platform that transforms how laboratory professionals understand quality — from analytical metrics to clinical consequence. Built around decision scenarios, not passive content delivery.

Pre-Analytical ErrorsSigma MetricsWestgard RulesELISA QCDelta ChecksISO 15189
Why This Course Matters

Quality systems prevent patient harm

Laboratory results drive 70% of clinical decisions. When quality fails, decisions fail.

70%

of clinical decisions are laboratory-driven

Treatment plans, diagnoses, and monitoring protocols all depend on laboratory data accuracy.

46–68%

of lab errors occur pre-analytically

Before the sample reaches the analyser — collection, transport, and identification failures dominate.

6 Sigma

performance target for clinical reliability

Methods operating below 3 Sigma are considered analytically deficient and clinically unreliable.

Diagnostic errors impact patient care

Missed diagnoses, delayed treatment, and inappropriate therapy — all traceable to laboratory failures.

Quality systems prevent harm

Robust QC, validated methods, and intelligent delta checks are patient safety infrastructure, not regulatory bureaucracy.

Labs are decision engines

A laboratory is not a test center. It is a clinical decision engine. Every result carries responsibility.

Lab System Architecture

The Total Testing Process

Every laboratory result passes through three phases. Error at any point propagates forward — often invisibly.

Pre-Analytical

46–68% of errors

Quality Checkpoints

Patient ID
Sample type
Collection time
Anticoagulant
Transport conditions
Storage

Error Points

Haemolysis
Wrong tube
IV contamination
Delayed transport

Analytical

7–13% of errors

Quality Checkpoints

Calibration
QC review
Instrument status
Reagent expiry
Interference check

Error Points

Calibration drift
Reagent failure
Matrix effects
Carry-over

Post-Analytical

18–47% of errors

Quality Checkpoints

Result review
Delta check
Reference intervals
Flagging
Reporting

Error Points

Transcription error
Wrong reference range
Unreported critical values

Clinical Decision

Patient Impact

Quality Checkpoints

Treatment
Monitoring
Diagnosis

Error Points

Delayed treatment
Wrong therapy
Missed diagnosis

Key insight: Most laboratories focus quality resources on the analytical phase — where only 7–13% of errors occur. The pre-analytical phase, responsible for the majority of errors, often receives minimal systematic attention.

Course Modules

Five modules. One integrated system.

Each module builds on the last — from foundational quality principles through to clinical decision integrity. Click any module to explore topics and the core question driving that module.

Case-Based Learning

Decision scenarios from real laboratory practice

Read the situation, study the data, formulate your decision — then reveal the rationale and teaching insight. Each case is drawn from real-world laboratory intelligence challenges.

Case 01 — QC Failure

Silent QC Failure in Glucose Reporting

Situation

Morning IQC run for glucose: Level 1 passes (mean +1.2 SD), Level 2 passes (mean +1.8 SD). No Westgard rule triggers. Results reported. Four hours later, a clinician queries a glucose of 2.1 mmol/L in an alert, asymptomatic patient.

IQC Level 1

+1.2 SD

Within limits

IQC Level 2

+1.8 SD

Within limits

Patient Glucose

2.1 mmol/L

Flagged by clinician

4-day trend

Systematic shift +

Not triggered by rules

Decision Challenge

No individual Westgard rule was violated. The lab passed QC. What went wrong?

Case 02 — ELISA Variability

ELISA Variability in Biomarker Research

Situation

An ELISA for serum HMGB1 is run on 24 samples across two separate plates on the same day using the same kit lot. Researcher reports a 28% difference in mean OD between plates. The intra-assay CV is acceptable (8%). The inter-assay CV exceeds 20%.

Intra-assay CV

8%

Acceptable

Inter-assay CV

22%

Exceeds target (15%)

Plate 1 OD (mean)

0.81

Reference plate

Plate 2 OD (mean)

1.04

Same kit lot

Decision Challenge

Results look consistent within each plate but differ between plates. Can you report both plates together?

Case 03 — Delta Check

Delta Check Abnormality in Sodium

Situation

An inpatient sodium result of 156 mmol/L is generated. The previous result 18 hours ago was 138 mmol/L. The laboratory system flags a delta check alert (change >12 mmol/L per day). The lab technologist is about to call the result. The sample was collected from an IV arm.

Current Sodium

156 mmol/L

Flagged

Previous Sodium

138 mmol/L

18h ago

Delta

+18 mmol/L

Exceeds threshold

Collection site

IV arm

Saline infusion noted

Decision Challenge

The delta check is positive. Should this result be reported, queried, or cancelled?

Interactive Learning

Learn by doing, not just reading

These course modules are directly integrated with laboratory intelligence tools. Use them while learning, not after.

ELISA Intelligence System

Applied in Modules 01, 03, 04

Live

Enter OD readings from ELISA plates and receive full QC analysis: intra-assay CV, inter-assay comparison, curve fitting, and quality flag generation. Apply directly to Case 02.

OD AnalysisQC FlagsCurve FittingInter-assay CV
Open Tool

Sigma Metrics Calculator

Applied in Module 03

Live

Calculate sigma performance from CV, bias, and total allowable error. Visualise performance on the sigma scale and determine appropriate QC rule selection based on analytical risk.

Sigma ScoreRule SelectionRisk AssessmentTEa-based
Open Tool
Teaching Layer

Viva preparation & practical intelligence

Structured questions for examination readiness, combined with practical insights and a guide to the most common conceptual mistakes.

Viva Questions

Common Mistakes to Avoid

Treating all Westgard rule violations the same

Distinguish warning rules (1-2s) from rejection rules (1-3s, 2-2s). Each has different clinical implications.

Assuming a passed IQC run means all patient results are accurate

IQC only monitors the analytical process. Pre-analytical errors are invisible to QC charts.

Reporting ELISA results from separate plates without inter-assay validation

Always validate inter-assay CV before combining data from different runs.

Ignoring delta check alerts under time pressure

Delta check positivity requires a structured decision pathway — never bypass it routinely.

Confusing total allowable error with expanded uncertainty

TEa is a performance goal; uncertainty is a measured property of a result. Both must be understood.

Practical Insights

Intelligence you can apply immediately

A 1-2s Westgard warning does not require run rejection. It should trigger surveillance of the next result.

Module 03

Sigma > 6 allows minimal QC (1 control per run). Sigma < 3 requires multi-level, multi-rule approaches.

Module 03

Haemolysis raises potassium by ~0.5 mmol/L per 1 g/dL haemoglobin — an important pre-analytical correction factor.

Module 01

Measurement uncertainty is not the same as imprecision. It includes all sources of variability in the measurement chain.

Module 04

A positive delta check should never be reflexively cancelled. It requires a structured decision pathway.

Module 05

Inter-assay CV >15% for low-abundance ELISA biomarkers means results from separate runs cannot be directly compared.

Module 04

Start Learning Laboratory Intelligence

Move beyond quality control compliance. Build the decision intelligence that protects patients and elevates laboratory medicine.

5

Modules

3

Case Scenarios

6

Viva Questions