Descriptive

Controls

Country differences

Mean for Roche instruments

Serum, Plasma

No of sample results

No of serum, thawed

No of serum, thawed used

Bias

Precision (worst methods first)

Effect of calibration

NS - not significant

General

Method specific

Systematic error

Precision

Albumin

5813

2819

2709

< 1 g/L: Dade, Kone, Hit 717

None

Obvious

Finland 0.8 g/L lower than mean (S)

No

Dade (ca –3 g/L)

*

Bilirubin

5809

2818

2740

Beckman Coulter (-4 umol/L)

Beckman

Not obvious except for Ortho

Finland 1.3 umol/L higher than mean (S)

No

*

Especially Cobas toward higher plasma values, the same also for Kone, Beckman towards lower plasma values

Calsium

5610

2703

2571

Generally lower values (plot error)

Kone

Obvious

Denmark 0.043 mmol/L higher than mean (S!!)

Tendency toward lower plasma values, especially for Ortho

Ortho

All, much worse than analytical precision

Cholesterol

5734

2766

2735

Generally lower values but not more than 1 mmol/L (plot error)

Kone

Obvious

Max 0.15 mmol/L different from mean (NS)

Generally lower plasma values, ecesially at higher concentrations (0 at 3 mmol/L, 0.3 at 8 mmol/L), but not Ortho!

Not Ortho (see general differences)

No

Creatinin

5663

2709

2636

Beckman and Hitachi both <-5 umol/L

Kone (best: Ortho)

Obvious

Norway -1.8 umol/L (S)

No

No

Kone, Beckman

Glucose

5099

2358

919

Generally too high values

Kone, Bayer

Obvious

Denmark +0.09 mmol/L (NS)

Higher plasma values, decreasing at higher concentrations

Not obvious

No

HDL-cholesterol

5447

2637

2603

Beckman low (plot error)

Kone

Moderate to not obvious

Iceland -0.03 mmol/L (NS)

No

No

Beckman, Kone

Iron

4966

2370

2311

Not more than 1 umol/L

No

Not obvious

Denmark +0.7 umol/L (NS)

No

(plot error)

(plot error)

Magnesium

4360

2198

2123

Roche Hitachi

Kone

Obvious

Sweden + 0.014 mmol/L (S)

No

No

No

Phosphate

5536

2656

2595

Generally lower values

Kone, Beckman

Some

Norway +0.04 mmol/L (S)

Lower plasma values, more at higher concentrations

No

No

Potassium

5871

2873

2608

Generally lower than target

Best: Cobas, worst: Kone

Not obvious

Finland -0.05 mmol/L (NS)

Clearly lower plasma results, incresing with increasing

Not obvious

Not obvious

Protein

4418

2097

1986

Higher values for all

*

Obvious

Sweden +1 g/L (NS)

Higher plasma results, about 2 g/L

Not obvious

Kone

Sodium

5868

2879

2642

> 2 mmol/L: Konelab, Optima (31), Konelab Microlyte 3+2 (32)

*

Obvious

Finland -1.1 mmol/L (S!!)

Somewhat lower values for plasma (but not for Hitachi!)

*

Beckman, Konelab

TIBC

1453

942

761

-3 umol/L for 2 of 3

No

Obvious

Denmark -0.8 umol/L (NS)

Lower plasma values ( -3 to –4 umol/L, only Hitachi plotted)

See general

See general

Triglycerides

5655

2714

1203

No

Kone, Bayer, Beckman

Not obvious

Denmark +0.16 mmol/L (NS)

Tendency to lower plasma values for higher concentrations, but not Ortho and Beckman (see cholesterol)

See general

No

Urea

5308

2584

2535

< -0.2: Both Kone

Worst: Beckman (4.7%), best Ortho(1.75%)

Small

Denmark -0.12 (NS) , Finland +0.12 mmol/L (NS)

No

No

Kone, if difference: To lower plasma results

Uric acid

5631

2708

2622

Konelab (-25 umol/L)

Bayer, Kone

*

Finland +13 umol/L (NS)

None

Beckman series with much lower plasma values

Kone – to lower values

5468

2937

955

*

*

Irrelevant

*

*

*

*

4123

2021

720

*

*

*

*

*

*

5148

2452

2145

*

*

*

*

*

*

5771

2869

2304

*

*

*

*

*

*

5485

2641

1855

*

*

*

*

*

*

5167

2836

459

*

*

*

*

*

*

5339

2557

1385

*

*

*

*

*

*

1617

850

497

*

*

*

*

*

*