HuQAS Proficiency Testing Design

INTRODUCTION

HuQAS is a ISO 17043 Accredited web-based PT provider Currently offering 40 Qualitative and quantitative PT programs with close to 300 participating laboratories in East, West and Central African countries. The PT program is based on Simultaneous model, where PT samples are distributed to all participants, who analyze the samples, sent results back to HuQAS for evaluation. Upon evaluation, HuQAS communicates the results to the participants within targeted turn around times.

METHOD

PT Items are tested for Homogeneity and stability, and distributed simultaneously to participants for analysis. Participants sign the delivery notes together with the sample condition form which accompany the PT items and scan a copy to HuQAS to confirm receipt of the panels. E-mail alerts inform of the opening and closing of the test events. Participants analyze PT items just the way they analyze patients samples and post results through the HuQAS informatics system portal. Posted results are evaluated using Qn and Hampel statistical program to obtain consensus.
 

Monthly programs have an analysis period of 5 to 7 days while quarterly programs have an analysis period of 14 days.
 

Analysis of Participants’ results.

1. Quantitative Programs:-

 a) Data analysis is done in line with HuQAS procedure, HuQAS/QP/0013, which is is Guided by clause 6.2 of ISO13528 and clause 3.12 of ISO17043; the HuQAS Informatics system, performs data analysis using the Robust statistical design which employs the Qn and Hampel method of analysis and is not affected by outliers.

Consensus value for participants’ results which have 15 data sets, based on the best fit principle, and above is generated, either in an All Peer or per specific method or Instrument Peer where different methods or Instrument provide results that are not comparable. Such data is not affected by outliers.
 

Failure to meet the threshold, or where the standard error is not acceptable, the system reverts back to the assigned value.
 

b) Determination of the assigned value by multiple accredited reference laboratories using a primary measurement method or a reference method., as guided by clause 7.3.1.4 of ISO13528.
 

c) Assigned value/Certificate of analysis especially for Certified Reference Materials, whereby, the values of measurements are provided for specific instrument models. A study by expert laboratories is also used to characterize CRMs to be used as PT items.

2. Qualitative and Semi-quantitative programs:-
These are analyzed using Assigned values as required in clause 11 of ISO13528 standard;

a) Expert judgment, based on the consensus of qualified experts.
b) By use of reference material of the PT test item, where the reference value is assigned.
c) From knowledge of the origin of the PT material, with confirmatory measurements.
d) Using mode or median of participants’ results, where the mode is used for results on a categorical or ordinal scale while the median is used as the assigned value for results on an ordinal scale.

PARTICIPANTS REPORTS

After 14 days of rigorous analysis of participants’ results, an interim report is released. In a weeks’ time, with no complaints from participants, Final reports are released. Mail alerts precede the release of the reports.

CONCLUSION

HuQAS meets the International standards requirements of a PT provider, committed to enable continual improvement of participants with evaluation of performance characteristics of the employed methods. Participants of the PT scheme have created confidence to their customers.