SERVICES

Proficiency Testing Services
What Is Proficiency Testing?
Proficiency testing is used by clinical/medical laboratories to verify the accuracy and reliability of their tests. Proficiency testing is a program in which multiple samples are periodically distributed to members of a group of laboratories for analysis and/or identification. The expected results/target results are only known by the proficiency testing service provider and none of the participating laboratories have access to the expected results. After the laboratory submits the results of the testing to the proficiency testing service, the laboratory's result is compared with other laboratories' results that use the same or similar testing equipment and reagents. The proficiency testing service scores the laboratory’s performance by comparing their results with the targeted value. Laboratory personnel may then evaluate the accuracy of their testing and take corrective action if their results are not acceptable.

Benefits of Participating in PT
There are several benefits of participating in Proficiency testing and these are as follows

To the Laboratory
  • It is a valuable tool for education: Participating laboratories have got a learning opportunity whenever they make corrective actions as well as when they receive challenging PT samples not commonly found in their laboratories
  • Self assessment against other laboratories: The PT reports clearly indicated how the participating laboratories would have performed against other participating laboratories.
  • System confidence: Through receiving correct results, participating laboratories can build internal confidence in their testing process.
  • Early warning system for problems: Should there be problems with equipment, internal quality Controls as well as Reagent Kits; PT can help the participating laboratory to identify the problem.
  • Indicator of where to direct improvement efforts: Participating laboratories may realize that they have a challenge in one or more of the schemes they participate in. This gives them knowledge of were to direct their effort in trying to improve the testing process.
  • Requirement for Accreditation: ISO 15189: 5.6.3 requires that laboratories participate in Inter-Lab Comparison/PT schemes. Where no formal PT is available, labs should participate in inter-laboratory activities


To the Nation

  • Public confidence in laboratory results: Information coming from the PT providers can give the public confidence in the results generated by participating laboratories.
  • Reliable data for epidemiological purposes:


To the Patient

The patient is ensured to receive accurate, reliable and useful test results from the participating laboratories.



ZINQAP PT Cycle
**Hover your mouse over each activity for more details ***


Laboratory Processing Results Receipt Sample Send Out Results Analysis Quality Control and Validation Client Report Sample Preparation Challenge Selection


PT Schemes on Offer.


Accreditation

ZINQAP PT Schemes are accredited to ISO Guide 43 and ILAC G13 through SANAS PTS0004. Please check the schedule of accreditation here on the SANAS website

Download Resources

For downloads, refer to the Resources page


2010 Shipment Calendar




Z-Scores.
ZINQAP now uses the ISO Guide 43 recommended z-scores as an indication of the performance of a participant laboratory for quantitative assays. Z-scores simply indicate the number of standard deviations a certain data point (test result) is away from the mean or target value. This score provides the lab and also its (potential) clients and accreditation bodies a good indication of its analytical competence. An advantage of the score is that it allows the participant laboratories to compare themselves against the target value and also against previous performance.

The formula for z scores is calculated as follows



Where

zki = z score for laboratory i on sample k; i=1,…,n.; k=1,…,p
Rki = Result from laboratory i on sample k; i=1,…,n; k=1,…,p
Mk. = Robust mean of results on sample k.
Sk. = Robust standard deviation of results on sample k.



The interpretation of the z-scores is easy:

Acceptable performance

| zki | < 2: or -2 < zki < 2
the participants result differs from the ‘true value’ less than 2 times the reproducibility standard deviation of the corresponding internationally accepted test method. Such a result is mentioned: good or satisfactory (will occur with normally distributed results in about 95% of all cases)

Questionable Performance

2< | zki | < 3 or -3< zki =-2 or 2= zki <3

Questionable (will occur with normally distributed results in about 5% of all cases)

Unacceptable Performance

| zki | > 3 or zki =-3 or zki =3
Unsatisfactory (will occur with normally distributed results in about 0.3% of all cases)


On-site Assessments
 On site assessments are routine quality audits conducted by trained laboratory personnel from the reference or intermediate laboratory or over-sight body, with the purpose of assessing the implementation of quality systems by laboratories and testing sites. During the assessments, a standardized checklist (ISO 15189) is used to assess all components of testing such as personnel competence, equipment, and laboratory safety, adequacy of supplies and implementation of internal quality controls among others. The whole testing process is analyzed to ensure adherence to standards. On-site assessments can also be used to determine staff competence in conducting specific tests.


Training Workshops
Trained and competent personnel are an integral part of any Quality Management System; hence a good QA programme must include training. The training comprises of power-point presentations on the course materials, group discussions and hands on practical sessions. Several courses are offered to medical laboratories so that they can strengthen their capacity towards laboratory accreditation. Training courses are designed after the review of the performance by participating laboratories. Areas of weaknesses are identified and ZINQAP develops courses to address these problems. Some of the courses on offer as follows:

  • Quality Assurance in Medical Laboratories
  • Strengthening Laboratory Management Towards Accreditation (SLMTA)
  • Quality Assurance Part I and II (City and Guilds)
  • ISO 15189 awareness course.

In-house courses are also designed depending on the specific needs of the participating laboratories.


Development of National Standard Operation Procedures


In 1996, ZINQAP produced National Standard Operation Procedures for medical laboratories in the following disciplines
  • Haematology
  • Medical Microbiology
  • Serology
  • Clinical Chemistry
  • General Laboratory Equipment Maintenance


New editions have since been published and participating medical laboratories can collect their copies from the office of the Director of Medical Laboratory Services, Ministry of Health and Child Welfare.