CK

CK (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				118.8		112.3	5.6	6
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

ck.GIF (3392 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 (46%)

ck2.GIF (4992 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 (108.6 U/L)

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

ck.gif (11613 bytes)

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

Raw data, female, male <50, male >=50

ck.gif (12486 bytes)

Age related reference intervals

Vitros (Ortho) results included

Values for female >515 and for male >885 are excluded (>4s, log-transformed)

ck2.gif (44035 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)

ck.gif (9555 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).

ck.gif (3614 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".

ck2.gif (23067 bytes)

ck2u50.gif (23965 bytes)

CK and relation to sample collection day of week

(Monday=1, Tuesday=2 etc.)

ck.gif (23166 bytes)

Comments (Pål Rustad): The reason for peak on tuesday and subsequent linear decrease is perhaps in accordance with physical activity on sunday. According to Tietz (Tietz Textbook on Clinical Chemistry, Third edition, 1999), the total CK reaches a peak at about 30 hours after onset of chest pain, and decreases to normal level after about 100 hours.

Cumulative CK distributions for each day of week

Only upper part of distributions are shown

ck_day.gif (12106 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.

ck.gif (4539 bytes)