The Laboratory Proficiency Rating Program provides robust, statistically rigorous reporting, as well as opportunities for subscribers to earn certificates and awards for high levels of accuracy in their results.
Proficiency Ratings
Proficiency reports are available in all series subscriptions. In addition to comparing results with other participants, subscribers receive quantitative estimates of laboratory accuracy via z-scores when there are six or more reporting participants.
How Proficiency Ratings Work
Our proficiency rating utilizes the internationally recognized z-score in determining accuracy assessments. Results from each series subscription are compiled and distributed to all subscribers, maintaining participant confidentiality.
Subscribers receive z-score reports at regular intervals throughout the year, enabling labs to monitor their progress. Accuracy scores are calculated for subscribers who have submitted data in all rounds for all analytes across the calendar year. Subscribers are eligible for a rating and are automatically considered when they submit results for all rounds in all program series.
The z-score represents the number of standard deviations by which a single result, or series of results, differs from the true value as represented by the consensus value. Outliers are removed from the series of results when determining the z-score, and attract a penalty. Laboratory accuracy is determined by the deviation of observed analytical results from the grand mean of all participating laboratories.
Certificates and Awards
Laboratories who have submitted for all rounds in a calendar year can earn award certificates depending on the level of their accuracy.
- Laboratories who obtain an adjusted mean z-score of less than 2.00 earn a proficiency rating of satisfactory for accuracy
- Laboratories who obtain an adjusted mean z-score of less than 1.00 earn a proficiency rating of outstanding for accuracy
All analyses reported by the subscriber will be included in the Proficiency Rating Program Certificate Status Calculations. Results must be reported for each round of the program from January to December of the certificate year. Refer to the current series protocol for the required analytes and Group 1 or Group 2 details.
Participation certificates will be available upon request for current subscribers who have reported results for all rounds of the specified group of analytes. Details on qualifications are outlined in the latest version of the series protocol.
