AST

AST (37ºC)

CAL target

Source: NORIP mean of instrument means for IFCC compatible methods.

Material	Nordic Trueness Project 2002			Reference method, DGKC 1997		NORIP
Material	MEP17-1 transferred value	Standard uncertainty	Median	Value	Standard uncertainty	Mean of instrument mean	s	N
CAL						23.6	1.1	7
X

CAL-corrected mean of control values X, P, HIGH (H), LOW(L)

For each method group all corrected values outside method group mean + 2s are discarded before calculation

ast.GIF (3356 bytes)

Instrument comparisons of mean and standard deviation of CAL

Only CAL values from laboratories with IFCC compatible methods

Y-axis: Concentration/activity. X-axis: Instrument producer (number of cal values in brackets)

Plot: Mean of CAL + 1 standard deviation

Laboratorys mean of CAL relative to "minimum" bias goals...

...expressed as Target value x (1 + 0.375 x CVb) where CVb is total biological variation expressed as a coeffisient of variation (22%)

ast2.GIF (5114 bytes)

Method specific %CV (all control values), median, maximum and minimum (no of labs in brackets on X-axis)

Distributions for different method types (both gender)

First corrected for slope/intercept submitted by lab, then corrected by using CAL-target (24.0 U/L)

Number of results and ref.interval in brackets behind description of each distribution

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Distributions of reference values according to proposed partitioning criteria for IFCC compatible methods (not CAL-corrected)

Raw data, female, male

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Age related reference intervals

Vitros (Ortho) results included

Values for female>58 and male >77 are excluded (>4s, log-transformed)

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Reference values and - limits (y-axis) against age (x-axis)

The rounded reference limits (red) are proposed by the norwegian enzyme group (see report)

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Country differences

Country mean for Hitachi/Modular instruments

Deviation from all mean ± error (2s/n^½ where s is standard deviation and n is number of data for each country).

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Country reference limits with 90% confidence interval.

Partitioning is indicated in the grey rows as Y (yes: <0.9% or >4.1% of subpopulation outside common reference limit), M (moderate: % outside is either in the interval [0.9%,1.8%] or [3.2%, 4.1%]), N (no: % outide is in the interval [1.8%, 3.2%]) as evaluated accoding to Ari Lahti's recommandations (but so far not taken into account).

The conclusions (N, M or Y) for partitioning (grey rows) for "Sum", "F", "M" for each country is relative to respective columns in "All".

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Mean of thawed serum reference values (person results) for each laboratory and instrument producer.

For enzymes, data for both controls and reference values are first recalculated back to original instrument data using slope and intercept reported by each laboratory.

Black points - not corrected by laboratory mean of CAL or X.

Red points - corrected by laboratory mean of CAL or X.

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