Scheme Information Sheets
UK NEQAS for Sweat Testing
| Scheme Particulars | Indicative Details |
|---|---|
| Accreditation body | UKAS |
| ISO/IEC Accreditation status | ISO/IEC 17043:2023 |
| UKAS Accredited Proficiency Testing Provider No | 7860 |
| Objective of Scheme | Provides EQA coverage for Sweat Chloride, Conductivity and Sodium testing. Sweat Chloride testing is performed as part of the diagnostic pathway for Cystic Fibrosis; some laboratories also measure Conductivity and Sodium as part of sweat assessment. The scheme provides assessment of analytical performance but also includes an interpretative element for Sweat Chloride and Conductivity, based on a clinical scenario given at each distribution, which assesses variation in the guidelines followed by participants in the scheme |
| Pre-, Analytical, Post- status | Analytical/Post |
| Number of distributions per year (nominal) | 11 |
| Specimens per distribution | 3 |
| Number of Specimens per annum | 33 |
| Frequency of distribution | Monthly |
| Scoring system | ABC |
| Material distributed | Sterile water 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) | 0.25 |
| Sample presentation TACs | All analytes in the same tube |
| Data in Chemistry on-line Dashboard | Yes |
| Analyte | Approx Range | Default Units | Target Value | B Score Limit (%) | C Score Limit (%) |
|---|---|---|---|---|---|
| Chloride interpretation | ~ | N, I or E | ~ | ~ | ~ |
| Conductivity interpret | ~ | N, I or E | ~ | ~ | ~ |
| Sweat Chloride | 20 – 100 | mmol/L | ALTM | 10.0 | 10.0 |
| Sweat Conductivity | 20 – 100 | units | ALTM | 10.0 | 10.0 |
| Sweat Sodium | 20 – 100 | mmol/L | ALTM | 10.0 | 10.0 |
| 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 |
