Scheme Information Sheets

UK NEQAS for Tox and TDM

Scheme Particulars Indicative Details
Accreditation body UKAS
ISO/IEC Accreditation status ISO/IEC 17043:2010
UKAS Accredited Proficiency Testing Provider No 7860
Objective of Scheme Provides EQA coverage for a wide number of both therapeutic (TDM) and Toxic (TOX) drugs. Seperate specimens are supplied for both the TDM and TOX drugs. The Toxic drug specimens contain drugs that require montoring to avoid levels becoming toxic and include Salicylate, Paracetomaol, Ethanol and Ethylene Glycol.

The TDM specimens contain a wide range of drugs that require monitoring for maintaining blood concentrations within a narrow theraputic range. This scheme provides both manipulated and endogenous specimens that cover both the therapeutic and toxic drugs concentration ranges for all drugs Specimens will often be targeted to important drug action or cut off levels as well as probing drug interactions or interferences that occur in immunoassays
Pre-, Analytical, Post- status Analytical
Number of distributions per year (nominal) 11
Specimens per distribution 3 (Separate specimens for Tox and TDM)
Number of Specimens per annum 33
Frequency of distribution Monthly
Scoring system ABC
Material distributed Pooled, liquid human serum with or without exogenous added analyte
Programme Director(s) / Organiser(s) Finlay MacKenzie
Criteria for participation All, but overseas by courier
Nominal sample volume (mL) Tox 0.6 TDM 0.9
Sample presentation TACs The TDM analytes are in a separate tube to the TOX analytes
Data in Chemistry on-line Dashboard Yes
Analyte Approx Range Default Units Target Value B Score Limit (%) C Score Limit (%)
Caffeine 0 – 50 mg/L XALTM 10.0 15.0
Carbamazepine 0 – 30 mg/L ALTM 15.0 15.0
Digoxin 0 – 4.0 µg/L ALTM 20.0 20.0
Ethosuximide 0 – 180 µg/L XALTM 10.0 15.0
Ethylene Glycol 0 – 2000 mg/L XALTM 10.0 20.0
Lamotrigine 0 – 50 mg/L XALTM 10.0 15.0
Lithium 0 – 4.0 mmol/L ALTM 10.0 15.0
Methotrexate 0 – 50 µmol/L ALTM 10.0 15.0
Paracetamol 0 – 400 mg/L ALTM 7.5 10.0
Phenobarbital 0 – 70 mg/L ALTM 10.0 15.0
Phenytoin 0 – 40 mg/L ALTM 10.0 15.0
Primidone 0 – 40 mg/L XALTM 10.0 15.0
Salicylate 0 – 650 mg/L ALTM 7.5 10.0
Serum Ethanol 0 – 4000 mg/L ALTM 7.5 10.0
Theophylline 0 – 40 mg/L ALTM 10.0 15.0
Valproate 0 – 180 mg/L ALTM 15.0 15.0
Abbreviation Expansion
ALTM All Laboratory Trimmed Mean
GLTM Group Laboratory Trimmed Mean – which is the Method Principle Mean
MLTM Method Laboratory Trimmed Mean – usually a manufacturer system / analyser mean
XALTM An external value that may be from a Reference Method System
OGLTM A Method Principle Mean used as the target for all laboratories
OMLTM A specific Method Mean used as a target for all laboratories
MED Median

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