Ten-year results of an international external quality control programme for measurement of anti-tuberculosis drug concentrations.

Objectives: Participation in an external (interlaboratory) quality control (QC) programme is an essential part of quality assurance as it provides laboratories with valuable insights into their analytical performance. We describe the 10 year results of an international QC programme for the measurement of anti-tuberculosis (TB) drugs.

Methods: Each year, two rounds were organized in which serum (or plasma) samples, spiked with known concentrations of anti-TB drugs, were provided to participating laboratories for analysis.