1 – Scheme overview

The goal of this scheme is twofold:

• Assess the accuracy of the results
• Evaluate the performance of the methods used in clinical settings (metabolites, interferences, etc.).

Longitudinal studies are carried out over several years to assess the popularity of the methods and their respective performances. Guidance and recommendations are issued with the results of these studies.

Participating labs can choose to be assessed for all the analytes of this scheme, or simply a subset of analytes of interest.

2 – Assessment frequency

Number of investigations per year: 4
Number of control samples per investigation: 1 or 2
Number of samples per year : 6

3 – List of analytes assessed

• Valproic acid
• Amikacin
• Caffeine
• Carbamazepine
• Ciclosporin
• Digoxin
• Gentamicin
• Lithium
• Methotrexate
• Phenobarbital
• Phenytoin
• Tacrolimus
• Teicoplanin
• Theophylline
• Tobramycin
• Vancomycin

4 – Description of the control samples

Lyophilized human control serums (samples to be resuspended in 5 mL of distilled water).

The sample matrix is not well suited for the determination of immunosuppressants (Ciclosporin and Tacrolimus). Between-method comparison is therefore not possible. However, their determination can be assessed using this scheme by comparison within each method group.