QUALITY CONTROL PLAN IN PoCT

QUALITY CONTROL PLAN IN PoCT

Worldwide, one of the fastest growing aspects of clinical laboratory testing is point of care testing (POCT), estimated to be increasing at least 10-12% per year overall and upwards to 30% per year in some testing areas. In contrast, central laboratory testing has grown approximately 6-7% annually.) When first widely introduced, POCT was largely for home use or physician office laboratory (POL) testing. In hospitals, it was considered as supplementary to central laboratory testing. It was not generally regarded as a primary responsibility of centralized pathology services and was often treated by central hospital laboratories with indifference, benign neglect, or frank hostility, and considered as substandard or second tier testing that was unmanageable. Some laboratorians considered POCT to be a potentially disruptive competitor to their services. POCT was also an added responsibility that many laboratories or nursing services found difficult to assume. The attitude of POCT as an inferior stepchild or orphan testing has changed with government regulations, the growth of the technology, an expanding perspective and spectrum of healthcare services, and different expectations from healthcare providers and consumers. Decentralized patient care and access to testing in under-served areas are key elements in the evolving expansion of POCT. POCT continues to mature both as a technology and in the eyes of healthcare providers, laboratorians, regulators, administrators, and vendors. While the technology has become more varied and robust and performance has improved, the various groups associated with POCT have grown more realistic and demanding about its potential. No longer does the Everest theory prevail — just because it exists does not mean POCT should be used in all situations. The need for comparability with central laboratory testing, efficacy, operational device and kit fail-safes, management and oversight requirements, operator performance standards, economic indicators, and patient outcome data are all now considerations when deciding whether to employ POCT in specific situations.

Point-of-care testing (POCT), or bed-side testing is defined as medical testing at or near the site of patient care. These are simple medical blood tests which can be performed at the bedside. Simple tests such as those found in medical examinations, urine test strips and even simple imaging such as with a portable ultrasound device. As well as regular observations such as ECG's, O₂ saturation and heart rate.

The driving notion behind POCT is to bring the test conveniently and immediately to the patient. This increases the likelihood that the patient, physician, and care team will receive the results quicker, which allows for immediate clinical management decisions to be made. POCT includes: blood glucose testing, blood gas and electrolytes analysis, rapid coagulation testing (PT/INR,Alere, Microvisk Ltd), rapid cardiac markers diagnostic (TRIAGE,Alere), drugs of abuse screening, urine strips testing, pregnancy testing, fecal occult blood analysis, food pathogens screening, hemoglobin diagnostics (HemoCue), infectious disease testing and cholesterol screening.

The Only Reason To Perform POCT 

v  Make diagnostic decisions

v  Make treatment decisions

v  Improve the efficiency of clinical operations

Benefits of POCT

An undisputable merit ascribed to POCT is the ability to produce and release analytical results earlier and easier than before by reducing the turn around time (TAT). This clear benefit, though, has to be balanced against a number of several potential risks. Moreover, “the faster the better” does not represent one and for all the best choice in any setting: timeliness depends on the specific clinical situation to be managed. The final decision should be made striking a balance among all the possible aspects, case by case. Often, a careful analysis of the whole process will lead to maintain a centralized diagnostics rather than to implement POCT. As a rule of thumb, it should be accepted that POCT is redundant whenever the laboratory can release a result as timely as clinically required. Taking into consideration that POCT is usually much more expensive than a centralized structure, its abuse always implies cost increases, not to mention the staff, whose training and management is also expensive: strangely enough this item is often ignored when preparing in-hospital POCT budgets. So it is mandatory to demonstrate that cost increases are fully counterbalanced by a much more efficient use of limited healthcare resources. Today, by virtue of spectacular progress in technology and detailed standards and regulations, POCT is much safer than a (even recent) past. Still, potential risks remain: staff with inadequate training, insufficient supervision, and lack of system governance and accreditation schemes. Again, it should be firmly stated that POCT can never be considered equivalent, rather an additional tool, for a clinical laboratory.

The variety of point of care tests (POCT) has evolved significantly in recent years. Whilst these instruments bring undisputed benefits in obtaining rapid results at the patient’s bedside, these benefits are only true if the results are accurate and reliable. Quality Controls (QC) exists to ensure accuracy and reliability.

For many of the health care workers using POCT instruments, QC will be unfamiliar territory. Many of the standard QC procedures applied in laboratories cannot be applied to POCT devices.  However, it is essential that both primary and community care settings apply well-structured QC procedures to ensure the accuracy and reliability of results, minimizing risk to patients and improving patient outcomes.

Point-of-care testing (POCT) is a complex system with many opportunities for error. Delivering quality POCT requires multidisciplinary coordination and an understanding of the preanalytic, analytic, and postanalytic processes that are necessary to deliver a test result and take clinical action. Most errors in laboratory testing occur in the pre and postanalytical phases and many mistakes that are referred to as lab error are actually due to poor communication, actions by others involved in the testing process, or poorly designed processes outside the laboratory's control. POCT requires significant operator interaction with analysis and documentation of calibration and quality control, unlike other medical devices. Clinicians often interpret POCT as equivalent to core laboratory testing, only faster, and mistakenly utilize the results interchangeably despite the differences in test methodologies. Taking quality of POCT to the next level involves looking beyond the analytical phase and integration of POCT into the entire pathway of patient care to understand how POCT relates to medical decision-making at specific points during the patient's care.

In recognition of this there is now an international standard for POCT, namely ISO 22870 which, in conjunction with ISO 15189, lays out the requirements for quality and competence.  However, there is no ‘one-size-fits-all’ solution.

Quality Control for POCT

Electronic quality control: EQC checks the electronics of the device but not the reagents or cartridge.

Auto-QC: Usually used on multi-use cartridge type devices especially blood gas analyzers. QC is performed automatically and verifed by the software on the instrument.

Built in QC: Usually used on single use visually read strips or instrument-read cartridges. Uses a control band that turns positive if the device is working correctly.

Developing an appropriate QC plan for POCT

Firstly, the actual design of the POCT device needs to be factored in. These broadly fall into 3 categories:

Laboratory type instruments – full size instruments, for example blood gas analysers. Similar to instruments you might find in a laboratory, the QC procedures for these types of analysers should follow full laboratory QC protocol. Multi-level QC samples should be run on these instruments every day a patient test is performed and the accuracy and reliability of those results should be monitored over time by participating in a frequent PT scheme.

Cartridge-based instruments – for example HbA1c and INR analysers. These are usually very different from that found in a standard laboratory, consisting of a cartridge based component and an electronic reader, which may have a self-check system built in. The cartridge contains all the necessary components for the analysis of the patient sample while the electronic reader is responsible for converting the results from the cartridge component into a readerable numerical value.

The difficulty with QC on cartridge-based instruments is that you can only ever test that one particular disposable cartridge and the electronic functioning of the instrument. However, for such devices QC is still essential. The cartridge may have been damaged during transit or the on-board reagents may have deteriorated over time. It is therefore recommended, as a minimum, to run QC when changing cartridge lot and periodically throughout the lifespan of the lot to ensure the stability of the on-board components. It would also be beneficial to participate in a frequent PT scheme to monitor the accuracy of reporting over time.

Strip based instruments – for example electrochemical or reflectance strip based glucose meters. These are similar to cartridge based instruments in that the strips are responsible for the analysis of the sample. However, unlike cartridge devices the electronic component has no self-check feature and without this a faulty analyser could be producing erroneous results for some time undetected. This makes QC even more important for these types of instruments. Strips should be checked using multi-level QC on delivery and every day of patient testing. Liquid-ready multi-analyte third party quality controls available from some QC manufacturers are ideally suited for this as they require no advance preparation and are easy for non-laboratory staff to use.

Regular proficiency testing is also important for these devices to ensure accuracy of reporting over time.

Proper Quality Control Reagents

Accuracy assessments are performed to verify that a system functions properly. Some manufacturers would recommend the use of liquid controls as a quality check. However, the composition of these liquid controls (also known as quality control reagents) should be as similar to whole blood as possible. Solutions such as red dye are not acceptable according to established ICSH standards. There is something known as the “Matrix effect” which is a term used to describe the differing performance characteristics between a liquid control and patient blood. This difference is hardly identifiable and almost impossible to trace reliably due to the complex chemical, physical, and biochemical interactions. Thus, even a Proficiency Testing (PT) and an external quality assessment (EQA) can yield inaccurate conclusions unless it uses whole fresh blood. The ICSH also recommends devices that use whole blood count instead of diluted blood.

Traceability

Traceability refers to the chain of referencing an instrument has. The ability of a manufacturer to say that their reference instruments for their systems have been calibrated against the international reference method established by the ICSH or by the National Institute of Standards and Technology is significant. It is plainly significant because just like other issues of standardisation, the user needs to know what to expect based on what is sold to them. In the medical field, standardisation has to do with life and the sustaining of life. There can be no compromise of extreme accuracy in this field. Therefore, having a standard reference that is traceable would also mean someone has to be accountable; and should there be issues raised or contrary findings appear, an already established platform is there to address it as a global community.

How to implement an in-hospital POCT system

First and foremost, the set up of a MSC, appointed by the top Management of the Institution to whom devolve power for:

²  sharing the project with all stakeholders;

²  representing in full the Authority presiding over the in-hospital POCT system;

²  defining competences and responsibilities for each component inside the project;

²  defining criteria for preliminary choices before starting with POCT;

²  carefully appraising the available resources;

²  selecting wards/services where POCT devices are to be placed;

²  selecting a test menu;

²  activating a regular scheme of clinical audit about the appropriateness of the whole organization in order to check:

²  system effectiveness, based on measurable outcomes;

²  system soundness;

²  evaluating on a regular basis the global cost/effectiveness;

²  planning continuous quality improvement of the system.

Who is responsible for POCT – clinicians or laboratory staff?

Responsibility for QC on POCT instruments, although located in the clinical setting, should ultimately lie with the laboratory. However it should be a team effort involving the staff who are using the actual equipment. Training of staff to use the POCT equipment, including QC, and the on-going competency of operators should be documented and governed as part of an overall quality management programme. Training staff who are using the POCT equipment to perform QC will give them a better understanding of how the equipment works and in doing so will help them to see for themselves when errors occur. However, ultimately the responsibility of quality control and should lie with the laboratory.

Disadvantages Of POCT

•Higher unit cost: Conventional wisdom POCT is more expensive than central laboratory testing

•Difficult to manage within in regulatory requirements

•Higher rate of operator errors in specimen collection, test performance, data management and documentation for regulatory compliance

GUIDELINES FOR CONDUCTING QUALITY CONTROL AND EXTERNAL QUALITY ASSURANCE FOR PoCT (AUSTRALASIAN ASSOCIATION OF CLINICAL BIOCHEMISTS )

1. QUALITY CONTROL (QC)

Minimum requirements for running quality control: QC shall be performed on all PoCT devices.

There are two main types of PoCT devices: low and medium complexity. The latter category includes blood gas devices that have a single use cartridge. Most PoCT devices have a large number of in-built quality checks.

For low complexity devices utilising strip technology (eg glucose or coagulation meters), a minimum of one liquid quality control (QC) sample shall be tested each month unless a higher frequency is suggested by the manufacturer. It is recommended that if only one QC sample is run it should have a concentration in the clinically relevant range for the analyte being measured. If two levels of QC are available, then control samples with both a normal and an abnormal level should be run.

Medium complexity devices utilising cartridge based technology (eg i-STAT, DCA) shall have a minimum of two liquid QC samples tested each month unless a higher frequency is suggested by the manufacturer. These two QC samples should contain normal and abnormal levels.

In addition to the regular QC program, QC testing should also be undertaken when:

v The lot number of consumables changes

v There is a new delivery of consumables

v An operator lacks confidence in a patient result

v The health care professional does not believe that the PoCT result fits the patient’s clinical picture

v Substantial maintenance procedures have been carried out on the device.

v The device has suffered a physical insult (eg dropped, temperature extremes – hot or cold, etc)

Electronic QC is a check of the device’s measurement signal only and does not check the analytical part of the system. Therefore it is complimentary to liquid QC requirements and not a substitute for the minimum QC requirements outlined in this document.

Who should run PoCT quality control samples?

QC testing for PoCT shall be undertaken by the PoCT Operator. All operators who at any time use the device should participate in the quality control program.

Who should be responsible for training PoCT Operators to test quality control?

Ideally there shall be a collaborative approach between PoCT Coordinators, suppliers and if appropriate the associated NATA/RCPA accredited laboratory. Minimum acceptable operator training standards shall be documented and available for review.

At completion of training, PoCT Operators should have their knowledge and technical competency assessed.

Who should be responsible for reviewing quality control results?

The PoCT Operator undertaking QC testing shall immediately review the QC results and take any appropriate action.

The PoCT Coordinator or delegate should be responsible for review and trend analysis of QC results, taking appropriate corrective action when required and operator participation. All QC records, reviews and corrective action documentation should be maintained for three years and be available for review.

2. EXTERNAL QUALITY ASSURANCE (EQA)

A form of external quality assurance should be undertaken for every PoCT device.

Participation in a recognised EQA program is recommended for each analyte being tested. Monthly split patient sample testing with an accredited laboratory may be considered as an alternative form of external quality assurance. This mode of EQA may be useful when a commercial program is either unavailable or unsuitable for the instrument in question.

Note: Users must be aware of limitations of using the split patient sample approach which include laboratory method performance, limited range of testing, transport stability and lack of peer comparison.

Who should run PoCT EQA samples?

EQA for PoCT should be run by the PoCT Operator.

Who should be responsible for training PoCT Operators to test EQA samples?

Ideally there should be a collaborative approach between PoCT Coordinators, EQA Scheme Organisers, suppliers and if appropriate the associated NATA/RCPA accredited laboratory. Minimal acceptable training standards, including refresher training should be documented and available for review.

At completion of training, PoCT Operators shall have their knowledge and technical competency assessed.

Who should be responsible for reviewing EQA results?

The PoCT Coordinator or delegate should be responsible for the review of EQA results and taking appropriate action. All EQA records, reviews and documentation should be available for review and maintained for three years.

POCT Quality Control Guidelines

TEST SUPPLIES AND CONTROL MATERIALS:

²  No expired Controls or Testing supplies.

²  Proper storage of controls and test materials. When Awarepoint temperature monitoring system is not available, Temperature Logs monitored in pyxis, rooms and refrigerators are required.

²  Testing reagents and supplies QC’d, dated (month/day/year) and initialed.

²  No loose supplies (Colo./Gast. Slides; Pregnancy Test kits). Test slides must be kept in the original box.

²  Control materials dated (month/day/year) and initialed. Write discard date (month/day/year) if shelf-life is based on open date; eg. glucose control solution expires in 90 days upon initial opening or the expiration date printed on the vial if it comes first.

QC LOGS:

²  QC frequency performed according to POCT policies and procedure.

²  Document all QC results on the QC logs.

²  Verify numeric QC results are within the numeric range noted on the QC log; e.g. Multistix QC pH result within QC range on log sheet. Follow QC log result manner of reporting.

²  Write “POS” for Positive and “NEG” for negative. Do not use ( + ) or ( - ) signs.

²  Document “Not In Use” (NIU) on days when patient testing not performed and QC not required.

²  Document Corrective Actions for FAILED QCs.

²  Control Materials and Test Supply lot #s must match lot # on QC log.

²  Use black or blue ink pens for QC documentations. Do not use pencil or red ink pens.

²  Error Corrections:

v Draw a line through error, Initials and Write correct results.

v No “Whiteout”

v No “Write Over”

v No “Xerox copies”

v Document all equipment maintenance.

v Managers/Supervisors must review and sign “Monthly            Manager/Supervisor Reviews” section of QC log.

v QC logs are kept for at least 3 years as required by law.

COMPETENCY:

Records of staff annual competency must be available.