PATH5191 Clinical Skills - Standardisation, Reference Material, Accreditation, Documentation, and Traceability

Introduction

  • First day on the job brainstorming.
  • Topics to be covered: Accreditation, Documentation, and Traceability.
  • Importance of the information.
  • Resources and their application.

Accreditation

  • NATA – National Association of Testing Authorities Australia.
  • NPAAC – National Pathology Accreditation Advisory Council.
  • TGA – Therapeutic Goods Administration.
  • AS4308-NZS4308/AS-NZS4760: Drug Testing.

NATA (National Association of Testing Authorities, Australia)

  • Accredits organizations to perform testing and inspection.
  • Provides assurance, competence benchmark, and national/international recognition.
  • Offers education and training.
  • Facilitates international recognition and innovative business solutions.

ISO Standards

  • ISO 15189: Medical laboratories.
  • Developed by the International Organisation for Standardisations's Technical Committee 212 (ISO/TC 212).
  • Based on ISO/IEC 17025:1999 (General requirements for the competence of testing and calibration laboratories) and ISO 9001.
  • Considers advice to users, sample collection, result interpretation, turnaround times, emergency testing, and lab's role in healthcare staff education.

Audits

  • Required by NATA.
  • Technical: covers all aspects of a method/procedure.
  • Vertical: traces all processes performed on a sample from start to finish.
  • Covers the entire request-test-report cycle.
Audit Requirements
  • Audit checklists.
  • Standard Operating Procedures (SOPs).
  • Controlled documents.
  • Training records.
  • Operator competency.
  • Electrical safety checks.
  • Temperature logs for refrigerators.
  • Reagent calibration logs.
  • QC and QAP review.
  • Sample identifiers, storage, and disposal.
  • Pipette calibrations.
  • Measurement uncertainty.
  • Corrective actions.
  • Documented procedures for urgent/abnormal results.

Documentation

  • Controlled documents.
  • Audits.
  • Manufacturer vs. in-house methods (TGA certification).
  • Record keeping.
  • Chain of Custody.
  • Medicare.

Controlled Documents

  • All laboratory methods are controlled documents.
  • Reviewed regularly (every 3 years).
  • Copies are kept in registered locations.
  • Printed copies are not controlled and must not be used.
  • Documents exist for all methods, training checklists, audits, temperature logs, etc.
  • Part of the Laboratory Quality System.

TGA (Therapeutic Goods Administration) Certification

  • Regulatory requirements for in-house IVDs (In Vitro Diagnostics).
  • In-house IVDs are pathology tests developed/modified within a lab for clinical diagnosis/management.
  • Different classes based on risk:
    • Class 4: Rule 1.1 (Detection of transmissible agents posing a high public health risk)
    • Class 3: Rule 1.3 (Detection of agents posing a moderate public health risk or high personal risk), Rule 1.2 (Detection of red blood cell antigens and antibodies and non red cell typing), Rule 1.8 (IVDs for export only)
    • Class 2: Rule 1.4 (IVD for self-testing for a serious condition, ailment or defect), Rule 1.6 (Instruments, reagents etc.), Rule 1.7 (IVDs not covered elsewhere in the classification rules), Determination of ABO, Rh, Kell, Kidd, Duffy systems
    • Class 1: IVD for self-testing that is preliminary and follow-up testing is required

Research vs Routine

  • Methods for research purposes may not need to meet all accreditation standards.
  • TGA approval is required for in-house methods or variations to manufacturer's instructions.
  • Documentation and validation data should be kept for all methods.

NPAAC (National Pathology Accreditation Advisory Council)

  • Promotes quality pathology services.
  • Collaborates with government, non-government, and consumer organizations.
  • Provides educational programs and engages with standard-setting organizations.
  • Monitors quality of Australian pathology practice.
Accreditation Requirements
  • Accreditation by NATA:
    • ISO 15189 for medical testing laboratories.
    • ISO 17025 for non-medical testing laboratories.
  • Meet NPAAC standard: Requirements for the Development and Use of In-house In Vitro Diagnostic Medical Devices.
  • NATA assesses the quality management system against ISO 15189 or ISO 17025.
  • NATA inspectors review technical documentation for in-house IVDs.

Record Keeping

  • Pathology reports are part of the patient's medical record.
  • Laboratories must maintain records demonstrating the validity of testing.
  • Minimum standards are based on Australian regulations and ISO 15189.
Retaining Specimens
  • Ensures a physical audit trail.
  • Allows additional testing if required.
  • Retention is required even if the specimen is consumed/unsuitable for testing.

AS4308 - Drugs in Urine

  • NATA Accreditation.
  • Australian Standards for workplace drug testing.
  • Ensures standardization of specimen collection and drug detection in urine.
  • Guidelines for collection, packaging, and transportation to an accredited laboratory.
  • Cut-off levels for positive identification of drug classes:
    • Sympathomimetic Amine Class
    • THC (Cannabis)
    • Benzodiazepine Class
    • Cocaine/Metabolite
    • Opiate Class
  • Non-negative results require confirmation by an accredited method like LC/MS.

Chain of Custody

  • Positively identify the person giving the sample.
  • Complete the Chain Of Custody form.
  • Ensure the toilet area is clear of substances that could contaminate the urine.
  • Supervise urine collection to prevent substitution.
  • Measure temperature within 4 minutes.
  • Seal the urine jar in the presence of the donor.
  • Sign all documentation.
  • Seal documents and urine in a bag for transport.
  • Sign when received, opened, and tested.

Traceability

Calibrator or Standard?

Types of Standards
  • Primary Standard.
  • Secondary Standard.
  • Certified Reference Material.
  • Reference Material.
  • Reference Standard.
  • Working standard.
  • Primary reference standard.
  • Working reference standard.
  • In-house standard.
  • Primary Standard: Highest metrological qualities, value accepted without reference to other standards within a specified context; restricted single use.
  • Secondary Standard: Value assigned by comparison with a primary standard.
  • In-house standard: Not an official pharmacopoeial standard; intended purpose demonstrated by the laboratory.
  • Certified Reference Materials (CRM): Benchmark standards or comparator substances analyzed simultaneously with the test sample; used for instrument calibration; traceable by unbroken chain of calibrations.

Metrological Traceability

  • AS ISO 15189-2013 (5.3.1.4):
    • Recording the metrological traceability of the calibration standard and equipment calibration.
    • Verifying measurement accuracy and system functioning at defined intervals.
  • Traceability to a reference material or procedure of higher metrological order.
  • If not possible, use certified reference materials, mutual consent standards/methods.
  • Concentration in an unknown by comparison with reference material.
  • Reference material can be prepared in-house or purchased as CRMs.
  • The extent of characterization depends on the intended use.

Certified Reference Material Examples

  • Cerilliant: Analytical Reference Standards (S(+)-Amphetamine).
  • trans-Hydroxy Perhexiline (Mixture of Diastereomers): Certificate of Analysis from TRC-Canada, but No claims re certified reference material and No MU data.
  • Cerilliant Oxazepam, Primary Standard: Solution Standard Verification ISO 13485.
  • Lipomed: Norbuprenorphine-D3 solution.
  • Chemical Reagents as standards – Sigma etc.
  • Reconstituted pharmaceutical compounds as standards – Teicoplanin?

Validity of Calibration

  • Regular use of certified reference materials and/or internal quality control using secondary reference materials.
  • Participation in inter-laboratory comparisons.
  • Internal reference material checked as far as practicable (17025).

Traceability Definition

  • A property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty.

Traceability Example: Serum Cholesterol

  • Measurand/SI: Serum cholesterol, substance concentration (mmol/L).
  • Primary Calibrator: NIST SRM 911c in ethanol.
  • Primary measurement procedure: ID-GC/MS.
  • Reference Calibrator: NIST SRM 1951b, Lipids in Frozen Human Serum.
  • Reference measurement procedure: CDC Abell-Kendall procedure.
  • Working calibrators: cholesterol in serum, or serum-like material.
  • End-user method: cholesterol oxidase method on an automated clinical chemistry platform.
  • Routine patient sample: Patient result: "serum cholesterol xxx mmol/L".

Traceability Statements Example: Creatinine

  • NIST SRM 967. Joint Committee for Traceability in Laboratory Medicine.
  • Value within 2.5% of true value
  • Calibrator lots should not change >+/- 2.5%

Spiking Standard Preparation

Powders:
  • Weigh out powder.
  • Correct for salts – as base.
  • Apply measurement uncertainty.
  • Record Retention.
  • Traceability – linked to MU.
  • Compare with previous batches.
Liquids:
  • Pipette known volumes of the vial contents.
  • Correct for salts – as base.
  • Apply measurement uncertainty.
  • Record Retention.
  • Traceability – linked to MU.
  • Compare with previous batches.

Spiking into Calibrators

  • Match the matrix – Consider ethics of use of blank matrix.
  • Homogenous matrix calibrators
    • solvent is in the spiking standard
    • What happens when it is dried down – salts of amphetamines less volatile?
    • What happens if you spike it in directly?

Stability

  • Characterisation of Secondary Standards
    • LOD loss on drying – purity
  • Use – don’t store – primary standards
  • Manufacturers instructions re Certified Reference Material
  • Accuracy – long term monitoring of performance – External QAP
  • Storage – desicants, Fridge, Freezer

In-House Calibrator Documentation

  • What information would you expect in the documentation describing the material?

Records

  • Identity.
  • Manufacturers name lot number.
  • Contact info.
  • Date of receiving, expiry, entered into service, taken out of service.
  • Acceptance for use (and criteria).
  • Ongoing acceptance.
  • Preparation information for in-house reagents.

Measurement Uncertainty

  • Contribution of Calibration to overall Uncertainty budget.
    • Type A analysis – use statistical analysis/tools
    • Type B analysis – use manufacturer’s info
  • Choice of concentrations
    • Cut-off levels
    • Expected therapeutic levels

Fish Bone Diagram - Measurement Uncertainty

  • A tool to visualise the contributing factors of measurement uncertainty.

Elements of Measurement Uncertainty

  • Pipettes for dispensing Standards Internal std pipette
  • #1 #2 #3 Cert of Analysis concentration
    • Precision Accuracy Precision Accuracy Random noise Random env. effects Temperature Sampling pipette Correlation of std curve Internal std pipette Instrument response Recovery Std curve preparation Concentration

Concentration Range

  • Appropriate to the expected concentration.
  • Therapeutic Ranges.
  • Cut-off levels.
  • Control values.

The Calibration Curve

  • Number of non-blank calibrators
  • MU of regression analysis
  • Uncertainty is greater at the extremes of the curve.
  • Measurement uncertainty around a 'cut-off' level

External QAP

  • More than just a check.
  • Harmonisation.
  • Tacrolimus experience.

Case Study - Tacrolimus

  • Lack of internationally recognised tacrolimus reference material. (Levine et al 2011)
  • “There was marked variability in terms of the storage conditions and expiration dates of reference material stock solutions. (Vinks et al 2014)
  • Multiple testing locations for mobile patients
  • Calibrators stock also used for control stock (Vinks et al)
  • Serial dilution for preparation of their calibrators. (Vinks et al)
  • 3 or less non-blank samples/calibrators (Vinks et al)
  • Matrix effects may be involved - to some extent.
  • Calibrators vary.

Internal Standards

  • What is an internal standard?
  • What is an isotope?
  • Isotopic purity of labelled internal standards for LCMSMS.
  • Will that affect Limit of Detection?

Method Review

  • Take a look at the method for Busulfan - Highlight sections that you now recognise?

Result Interpretation

  • Now that you've got a number, what are you going to do with it?

Interpreting Laboratory Results

  • All results are interpreted by comparison.
  • Comparison may be with:
    • A clinical decision point
    • A population reference interval
    • A previous result from the patient

Valid Comparisons

  • Your results must be unbiased relative to the comparator.
  • Clinical Decision Point - Method used to perform the study
  • Population reference interval
    • Method used for the reference interval study* - May be your laboratory or elsewhere
  • Previous result on the patient - Method used for the previous result