C1 Inhibitor and Functional Complement EQA

Accreditation Status:

Date Scheme started:

2002

Clinical Applicability:

Diagnosis of Hereditary Angioedema and monitoring of complement activation

Analytes:

Performance will be monitored in the antigenic and functional assays for C1 Esterase Inhibitor. Laboratories are required to return data on Complement C3 and C4 to permit the interpretation of the C1 Esterase Inhibitor levels (SER/033)

Units for Reporting:

g/L in relation to relevant international standards, functional activity (%)

Samples Distributed:

Liquid format. Normal and pathological human serum

Number of Distributions per year:

Number of Samples per Distribution:

Frequency of Distributions:

Every three months as outlined in the Distribution Schedule

Schedule of Analysis:

Data entry is via the web for the submission of results. Data analysis commences 28 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. The Designated Value (DV) for calculation of VI is the All Laboratory Trimmed Mean (ALTM)

Chosen Coefficient of Variation is 10%

Performance Scoring:

MI scoring and MRVIS

Criteria of Performance:

OMIS for qualitative results over a running analytical window of 4 Distributions (12 months)

	OMIS
Good	Zero
Adequate	1-2
Poor	>2

Laboratory performance for quantitative results is classified in terms of the MRVIS over a running analytical window of 4 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