Trials

1. Purpose

This description of the evaluation and reporting of the QuaDeGA proficiency testing is intended to help you as a participant to correctly interpret the assessment of your measurement results and to gain a comprehensive overview of the proficiency test for ejaculate diagnostics.

2. Process Description

2.1 General Information

The reporting is based on the specifications of the standard DIN EN ISO/IEC 17043:2010-05, section 4.8.2.
The reports are stored on the QuaDeGA online platform: https://evaluation.quadega.de and can only be accessed by logging in with individual credentials.

2.1 Explanation of the Proficiency Test

The QuaDeGA proficiency test includes:

Sperm concentration determination from two fixed ejaculate samples
Sperm motility assessment from video sequences available on the platform
Sperm morphology (normal form) assessment from stained smear slides prepared by the participant

Each year, two proficiency tests are conducted, each with two samples for each parameter.

Each shipment of the proficiency test includes detailed instructions on how to store and process the samples for sperm concentration and morphology analysis. Further information regarding the proficiency test and sample handling is available in the FAQ section at www.quadega.de. The video sequences for motility analysis and the corresponding measurement entries are accessible at any time via the QuaDeGA platform: https://evaluation.quadega.de.

After the completion of each test event (proficiency test), the evaluation is generated automatically. Each event is clearly labeled with a consecutive number and date, for example: “QuaDeGA 44 (Round 2 – 2023)”. “Round 2” refers to the second proficiency test in the year 2023.

2.1.1 Homogeneity – Stability

The sperm pools used for concentration determination are mixed with a fixative medium that preserves spermatozoa for at least six weeks after sample dispatch. Samples can be stored at room temperature or refrigerated. Stability has been verified in preliminary tests and is continuously monitored microscopically during each proficiency test.

Homogeneity is verified before dispatch through documented sampling controls. Weekly monitoring of Youden plots is performed after dispatch to detect irregularities (e.g., dual clustering) and investigate potential causes.

2.2 Target Value Determination

The target value is the median of measurement values from around 80 laboratories, jointly selected with the German Medical Association, which are unaware that their results are being used to determine target values. The data from these laboratories is ranked ordinally. The upper and lower target ranges are determined by excluding the outer 2.5 percentiles to remove outliers. The target value is the upper median of all measurement values.

No method-based evaluation is conducted; all measurement values are evaluated equally.

2.3 Evaluation

You will receive the evaluation of your measurement results in the following formats:

2.3.1 Tabular Overview

This table includes your measurement values, the target values, upper and lower pass thresholds, and your percentage deviation from the target value. Your performance is ranked as follows:

Rank 1: Both results match the target values
Rank 2: One result matches the target values, the other does not
Rank 3: Both results deviate from the target values in the same direction (systematic error)
Rank 4: Both results deviate from the target values in opposite directions (multiple sources of error)

The legend for the ranking system and the materials/methods used for measurement are also listed.

2.3.2 Graphical Representation

A Youden plot shows the results of all participants. A graph is generated where the value for Sample A is plotted on the X-axis and Sample B on the Y-axis. Your result is highlighted in a different color. The parameter is considered passed if the point lies within the target window, which is clearly marked in magenta. A separate Youden plot is created for each parameter.

2.4 Certificate – Qualified Proof of Participation

The proficiency test is considered passed when the measurements for sperm concentration, normal morphology, and progressive motility are rated as Rank 1 (i.e., both samples A and B fall within the target range). Measurements for non-progressive (NP) and immotile (IM) sperm are not considered (RiLi-BÄK 2019). If all three relevant parameters meet the target for both samples, a certificate is generated as a PDF in both German and English. It can be downloaded and printed from the “Download Documents” section.

The certificate includes:

Contact details
Issue date
Unique event name with sequence number
Information on the setup and implementation of the proficiency test
Digital signature of the QuaDeGA managing director (test coordinator)
Number of participating laboratories
Validity period of 12 months (stated on the certificate)

If a participant fails to meet the target values for one or more parameters, a qualified certificate of participation is issued showing the ranking results.

2.5 General Certificate of Participation

Every participant who has entered measurement results will receive a certificate of participation, which does not include evaluation results.

Each certificate contains:

Contact information of QuaDeGA GmbH
Contact information of the program coordinator and proficiency test leader (QuaDeGA managing director)
Issue date
Unique event name with sequence number
Information on test structure and implementation

2.6 Subcontracting

The calculation of measurement results, statistical analysis, and generation of certificates/participation confirmations is automated and takes place at the end of the test phase on the QuaDeGA platform: https://evaluation.quadega.de.

Responsible for the platform programming and maintenance is:

IMBEI – Institute for Medical Biometry, Epidemiology and Informatics
University Medical Center of Johannes Gutenberg University Mainz
Obere Zahlbacher Straße 69
55131 Mainz, Germany
Contact

2.7 Metrological Traceability

Due to the specific method used for determining the target values for the parameters under investigation, information regarding metrological traceability and measurement uncertainty is not provided.

2.8 Confidentiality

Your personal data and proficiency testing results are treated confidentially. Individual data will not be disclosed to third parties.

2.9 Recommendations – Complaints

You are welcome to contact us if you have any questions, complaints, or suggestions regarding the evaluation of your measurement results or your certificate.

A high learning benefit can be achieved by reanalyzing the proficiency test materials after completion of the respective round and comparing them with the target values. The video sequences are available to you for five years. Sample materials for sperm concentration and stained smears can be provided afterward as well, provided sufficient stock is available.

In the years 2017, 2019, and 2022, we conducted surveys among all German-speaking participants. The evaluations have contributed to general recommendations regarding the QuaDeGA proficiency testing program and have been published. We are happy to send you these publications upon request.

Contact:

QuaDeGA GmbH
c/o Centrum für Reproduktionsmedizin und Andrologie
University Hospital Münster
Albert-Schweitzer-Campus 1, D11 (Access: Domagkstraße 11)
48149 Münster, Germany
Email: info@quadega.de
Phone: +49 (0)251 8356445
Fax: +49 (0)251 8358236

Managing Director and Proficiency Test Coordinator:
Univ.-Prof. Dr. med. Hermann M. Behre

Quality Management Representative (QMB):
Barbara Hellenkemper

3. Applicable Documents and Attachments

3.1 Applicable Documents

Conformity Assessment – General Requirements for Proficiency Testing (ISO/IEC 17043:2010), Section 4.8.2
Guidelines of the German Medical Association for Quality Assurance of Laboratory Medical Examinations, adopted by the Board of the German Medical Association in its meeting on 18.10.2019, most recently amended by resolution of the Board on 14.04.2023