Cerebrospinal Fluid Proteins and Biochemistry EQA

Accreditation Status:

UKAS Schedule of Accreditation

Date Scheme started:

2000

Clinical Applicability:

Assessment of neurological disease

Analytes:

CSF Total protein, albumin, IgG, glucose and lactate (SER/041)

Units for Reporting:

Total protein g/L, Albumin and IgG mg/L, Glucose and Lactate mmol/L in relation to the relevant International Standards.

Samples Distributed:

Liquid format. Normal or pathological CSF will be distributed whenever sufficient volumes can be obtained. Most samples will, however, be of an artificial matrix developed for use in the programme.

Number of Distributions per year:

Number of Samples per Distribution:

Frequency of Distributions:

Every two months as outlined in the Distribution Schedule

Schedule of Analysis:

Data entry is via the web for the submission of results. Data analysis commences 21 days after sample dispatch. Late returns are accepted and will contribute to the laboratory's cumulative performance statistics.

Data Analysis:

All Laboratory Trimmed Mean (ALTM) with truncation at 2SD, SD, and CV%.

Reports also show method and manufacturer specific statistics. Individual laboratory performance is expressed in terms of MRBIS, SDBIS, and MRVIS

Chosen Coefficient of Variation:

Total protein 8%
Albumin 9%
IgG 6.5%
Lactate 6%
Glucose 4%

Performance Scoring:

MRVIS

Criteria of Performance:

Laboratory performance for the quantitative biochemistry element is classified in terms of the MRVIS over a running analytical window of 6 Distributions (12 months)

	MRVIS
Ideal	<50
Good	50-100
Adequate	101-200
Poor	>200 or SDBIS > 200

Persistent Poor Performance:

Defined as being in the Poor Performance category for two or more successive Distributions