ALP

ALP (37ºC)

(updated 20/1-2005)

Final reference intervals are calculated from a total of 954 reference values of which 459 serum samples were randomly selected (4 laboratories from each of Denmark, Finland, Norway, Sweden) and remeasured on Roche Modular* and 495 reference values submitted by laboratories using Vitros instruments. Both methods are compatible with IFCC recommended method at 37 °C.

*Danderyds sjukhus, Stockholm, Odense universitetshospital, Odense and Fürst Medisinsk Laboratorium, Oslo

CAL target

Source: Mean of values from remeasurements by Danderyd, Odense and Fürst Med.Lab.

Material	Nordic Trueness Project 2002			Reference method, DGKC 1997		NORIP
Material	MEP17-1 transferred value	Standard uncertainty	Median	Value	Standard uncertainty	Mean	s	N
CAL						64.02	1.25	35
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

alp.GIF (3468 bytes)

Instrument comparisons of mean and standard deviation of CAL

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

Regression analysis from reanalysis of 459 samples from randomly selected laboratories (4 from each of Denmark, Finland, Norway, Sweden) on Roche Modular for LD and ALP.

Data used is only from laboratories specified a factor different from 1. The regression (x: Roche, Modular - y: Methods shown in table) have been made using standard regression analysis with the constraint that intercept should be 0. R² is correlation coefficient and N is number of data.

	ALP
	Slope	R²	N
Ortho (Vitros)	1.022	0.8297	86
Olympus	0.9617	0.9943	23
Roche (Cobas)	0.955	0.8847	67
Beckman Coulter	0.9995	0.9876	24
Dade Behring	1.0443	0.9841	28

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 (26%)

alp2.GIF (25184 bytes)

Method specific %CV, median (all control values), 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 (64.2 U/L).

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

alp.gif (12696 bytes)

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

Raw data

alp.gif (8096 bytes)

Age related reference intervals

Vitros (Ortho) results included

Values >188 are excluded (>4s, log-transformed)

alp2.gif (44538 bytes)

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

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

alp.gif (8779 bytes)

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).

Finland is included in Denmark label.

alp.gif (3964 bytes)

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".

ALP2.gif (22478 bytes)

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.

alp.gif (4249 bytes)