The Percentiler and Flagger programs

The Percentiler and Flagger programs

Patient medians and flagging rates are normally stable over time, and any change is usually due to pre-analytical or analytical instability or error. “The Percentiler” and “the Flagger” are tools for quality assurance in medical laboratories. In these programs, results from selected patient groups are used to calculate instrument- specific daily medians, as well as the percentage of patient results outside the reference limits. Laboratories can participate with results from a wide range of common clinical chemistry analytes and basic hematology. At present, more than one hundred laboratories from around the world participate in one or both programs, most with more than one analytical instrument. As of January 2019, participation is free of charge. 

We ask for input to develop a new and innovative program that will replace the current version of the Percentiler- and Flagger programs.

The Percentiler and Flagger programs are currently being updated and will be replaced by a new program. A re-launch is planned for autumn 2023. The new program will provide new functionalities and allow stratification based on several new parameters. The current Percentiler- and Flagger programs will be merged into a single new program, though it will still be possible to participate only in what is currently the Percentiler program.

The new program aims to increase the benefits for participating laboratories, the wider laboratory community, and EQA providers. The new program is designed to:

1) provide user-friendly and flexible presentation of the data

2) show variation over time and

3) enable participants to compare different groups, e.g., different measurement procedures

We hope that all currently participating laboratories will find that the new software gives more and better information to support their daily work. Also, we believe the new program can be an essential tool to provide real-time knowledge about measuring systems and / or differences between measurement procedures and contribute to monitoring the equivalence of patient results reported from different measuring systems and measurement procedures. Therefore, we think this new program will provide knowledge helping laboratories to give better services to medical doctors, and in the end better health care to patients. 

Remaking the program is a huge effort for us, and we highly appreciate any suggestions for improvements. Please send an email to if you have suggestions or other comments.

Results from the Percentiler- and Flagger programs – Report Dec. 2020

We have produced a report to all participants to give a general overview of some results and findings, mainly from the Percentiler program, but also from the Flagger program. If you miss the report, please contact us so that we can update your contact information.

We do hope you will find the report useful.

The Percentiler program:

  • Participating laboratories calculate, and report instrument-specific medians based on patient results. The total number of patient results is also reported.
  • Ideally, patient medians are reported daily, but less frequent reporting is also possible.
  • Results are exported to a central database by standardized e-mails.

The Flagger program:

  • Participating laboratories calculate, and report instrument-specific percentage of patient results above and below the reference limit.
  • Ideally, flagging rates are reported daily, but less frequent reporting is also possible.
  • Results are exported to a central database by standardized e-mails (containing an additional two columns compared to The Percentiler export).

Laboratories can choose to participate in the Percentiler program only.

Presentation of the Percentiler- and Flagger programs
Analytes in The Percentiler/Flagger-program
Report Dec. 2020

Why participate?

Access to a laboratory’s results is only possible through their unique and individual account, but participants can compare their own patient medians to those of others in a dynamic and interactive visualization tool. For analytes with more than 20 participants, results are stratified according to type of instrument to allow further comparisons between laboratories using the same instrument. Furthermore, participation allows laboratories to follow their own patient medians and flagging rates over time. A detection of any change may, if necessary, allow the laboratory to initiate prompt investigations of possible pre-analytical or analytical issues. 

What does it take to participate?

Laboratories wishing to join the programs should contact Noklus to receive a protocol describing in detail how to report results.

Contact information: Anne Elisabeth Solsvik