GLI GLI Quality Tool
GLI Quality Tool — Version 2.0

Designing TB Lab Proficiency Testing Panel Rotations

Australia records relatively low tuberculosis incidence, yet the country relies on a tightly coordinated network of reference and peripheral laboratories to maintain diagnostic confidence. A well-designed proficiency testing panel rotation schedule underpins every assurance claim a TB laboratory makes, particularly when test volumes are modest and operators may encounter culture-positive specimens only intermittently.

Designing such a schedule is rarely straightforward for laboratories in regions like the Northern Territory or Tasmania, where sample throughput is small and staff often perform multiple roles. The challenge lies not in the technical act of testing a panel but in the organisational discipline of ensuring panels arrive on time, results are captured consistently, and corrective actions feed back into routine practice.

The four-phase roadmap published through the GLI quality management resources framework provides a useful scaffold, aligning proficiency testing with the broader Quality Systems Essentials. Panels become living instruments rather than annual obligations, integrated with internal quality control, audits, and the everyday workflow of the bench.

For Australian laboratories, the schedule also has to align with national expectations around accreditation, notification, and reference network participation. Building it thoughtfully from the start saves considerable rework later and demonstrates maturity during external assessments.

Defining Objectives and Scope of the Rotation

Before listing strains or selecting matrix types, a laboratory needs to agree on what the rotation is meant to achieve. Some facilities prioritise competency assessment for individual analysts, while others treat panels as a periodic check on the entire test pathway, from specimen reception to final reporting. Both purposes are legitimate, but they shape the schedule in different ways.

In a Queensland-based laboratory serving metropolitan Brisbane and outreach clinics in the Torres Strait and Cape York, scope may need to cover conventional smear microscopy, MGIT culture, line-probe assays, and molecular detection. A rotation designed only for smear microscopy would leave major gaps. A small district laboratory in Hobart might legitimately limit scope to microscopy and rapid antigen detection if referral pathways are well established.

Objectives should also reference local regulatory frameworks. NATA accreditation to ISO 15189 expects laboratories to participate in inter-laboratory comparisons where available and to justify non-participation where it is not. Defining scope early makes those justifications easier to defend during an assessment visit.

Mapping Panel Composition to Local Epidemiology

Panel materials should reflect the circulating Mycobacterium tuberculosis complex strains a laboratory is most likely to encounter. In Australia, this typically means including reference strains representing common lineages alongside representatives of Beijing and East African-Indian lineages, which have appeared in clusters linked to travel from high-burden regions.

Local demographic realities matter too. Communities in Western Australia and South Australia have reported higher notification rates among overseas-born residents and, in some regions, among Aboriginal and Torres Strait Islander peoples. Panels should occasionally incorporate challenges relevant to those populations, such as isoniazid-monoresistant strains or mixed cultures where microscopy might miss a small proportion of bacilli.

A practical approach is to maintain a matrix that lists each panel slot, the expected test method, expected result, and the competency the slot is intended to verify. This matrix then becomes the master reference against which the schedule is built.

Common components worth considering:

Sourcing and Preparing Panel Materials

Reliable sourcing is the foundation of any credible rotation. Many Australian laboratories source well-characterised strains from reference facilities within the Australian Mycobacterium Reference Laboratory Network, including the Royal Melbourne Hospital Mycobacteriology Laboratory and the Queensland Mycobacterium Reference Laboratory at Pathology Queensland.

Once strains are sourced, preparation must be tightly controlled. Aliquoting should occur in a biosafety cabinet under conditions that match routine specimen handling, and each aliquot needs to be quantified using a validated method such as colony-forming unit counts on solid media or turbidity standards calibrated against McFarland references. Inactivation protocols, where used for molecular-only panels, must be validated to ensure no live organisms reach the bench.

Stability and storage are practical concerns that often determine the rotation interval. Lyophilised preparations tolerate longer intervals, while frozen broth preparations may demand shipment on dry ice and shorter shelf lives. Schedules should reflect these constraints rather than ignore them, because a panel that loses viability mid-rotation invalidates the entire exercise.

Establishing the Rotation Cycle and Frequency

Frequency decisions are partly driven by sample volume and risk. A high-volume laboratory processing dozens of specimens daily might reasonably schedule panels twice a year, while a low-volume facility in a remote setting may benefit from three or four smaller rotations to keep the competency loop short.

The Royal College of Pathologists of Australasia Quality Assurance Program already provides external proficiency testing for many Australian laboratories, and this should be treated as a fixed anchor in the calendar. Internal panels can then be scheduled in the months between external events to fill gaps and reinforce learning.

A typical annual rhythm might look like this:

The exact rhythm should be documented with explicit dates, responsible persons, and contingency windows for shipment delays, equipment failure, or outbreak surge activity.

Coordinating With Reference Networks and External Providers

Proficiency testing rarely operates in isolation. Coordination with reference laboratories, state tuberculosis programs, and external PT providers keeps the schedule aligned with broader surveillance goals and prevents duplication.

The Public Health Laboratory Network and state-based tuberculosis services across Australia often distribute reference materials or alerts that can inform panel selection. Engaging them early also opens opportunities to share anonymised results, contributing to a clearer national picture of laboratory performance.

Where commercial PT providers are used, contracts should clearly define turnaround times, acceptance criteria, and reporting templates. If a provider cannot supply a particular challenge strain, the laboratory should have a documented fallback, such as a blinded re-test of a routine specimen or an exchange with a neighbouring laboratory.

Documentation, Data Capture, and Corrective Action

A rotation schedule is only as valuable as the records it produces. Each panel event should generate a complete file covering panel composition, shipment records, receipt conditions, raw results, expected results, analyst interpretations, and any deviations observed.

Corrective action documentation deserves particular attention. Where results diverge from expected values, the laboratory should record root cause analysis, retraining where relevant, and any changes to standing operating procedures. In an Australian context, such records form part of evidence during NATA surveillance visits and may be requested by state health departments under notifiable disease legislation.

Trend analysis across multiple rotations reveals patterns that single events cannot. A recurring issue with a particular method or analyst becomes visible only when results are reviewed longitudinally, allowing targeted intervention before performance drifts further.

Reviewing and Continuously Improving the Schedule

The schedule itself should be reviewed at least annually, ideally as part of the management review required by ISO 15189. Reviewers should ask whether panel composition still reflects circulating strains, whether frequency remains appropriate, and whether corrective actions from previous rotations have been effective.

Feedback from participating staff is invaluable. Analysts in regional centres may identify practical issues that desk-based reviewers overlook, such as packaging that is difficult to open safely or instructions that assume a higher literacy than the local workforce.

When reviewers identify persistent weaknesses, the schedule should be adjusted rather than the data. Adding a new challenge strain, increasing the frequency of a particular method, or rotating responsibility among analysts are all reasonable responses. The goal is a living schedule that strengthens the laboratory each year rather than a fixed calendar that simply marks time.

Laboratories that have refined their rotation schedule over several cycles often find it becomes one of the strongest pieces of evidence they can present during accreditation assessments, internal audits, and stakeholder meetings. It demonstrates that quality is operational, not aspirational.

Readers who want to share what has worked in their own setting, or flag gaps in the guidance, are warmly invited to share feedback with the tool's developers.