LD (37ºC)

(updated 20/1-2005)

Final reference intervals are calculated from remeasurements* of 459 serum samples from randomly selected laboratories (4 from each of Denmark, Finland, Norway, Sweden) on Roche Modular using a method 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.

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

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

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

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.

Laboratory's 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 (17.2%)

*All submitted values from participating laboratories included

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 (141.6 U/L)

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

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

Raw data

Age related reference intervals

No values excluded (>4s, log-transformed)

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

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

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 result

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".

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

*All submitted values from participating laboratories included

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.

Comments: None.

Maximum, mean and minimum of all reported reference values* (person results) for each laboratory sorted on mean.

*All submitted values from participating laboratories included

Correlation with Body Mass Index (weight/height²)

Only plotted data that are used for reference interval calculation.

Comparisons thawed serum (x)/fresh plasma (y) (regression plot)

All submitted values from participating laboratories included

Comments: None

Comparisons fresh serum/thawed serum (regression plot)

All submitted values from participating laboratories included

Instrument comparisons thawed serum (x)/fresh plasma (y)

Comments: None