Tools, Technologies and Training for Healthcare Laboratories

A selection of SEKK-DMax specifications

The Czech EQA program SEKK has one of the largest lists of analytical quality performance specifications. They are modeled after what's called the Dmax. How does this specification compare to TEa? Let's see.

A Selection of SEKK Dmax (2015) analytical performance specifications

SEKK is the Czech Republic EQA programme

These performance specifications listed below are created for a unique specification called Dmax.

Dmax is "the long-term reproducibility multiplied by 2.5, where 'long-term reproducibility' means: (2 years) in CV% either [1] average CV of all results of all EQA rounds from last 2 years for those analytes where we use only one assigned value (that is - all resuls are compared to one assigned value) or [2] average CV of peer groups with N> 10 participants for those analytes where the results of participants are normally evaluated within homogenous groups (that is - each group has individual assigned values)."

"The size of Dmax we verify by the calculation based on intra-and inter-individual biological variability (database c. Ricos) and we aim not to set the value of the Dmax more stringent than that obtained by calculation from biologic variability (with some exception, e.g. CRP)."

In other words, Dmax is more reflective of "state of the art" since it is built on estimates of actual historical performance of test methods, and the goal is not to develop specifications more stringent than what biologic goals would dictate.

Below is a selection of the SEKK Dmax. A full list would cover hundreds more analytes in additional scenarios, including CSF, POC, etc.

Sample
type
Analyte
Dmax CLIA 2014 Ricos Desirable TEa
Serum Amylase 15  30 14.6
Serum α-fetoprotein (AFP) 20 ± 3 SD  21.9
Serum Alkaline phosphatase (ALP) 24 30 12.04
Serum Albumin 12 10  4.07
Urine Albumin up to 30 mg/dL: 30%
above 30 mg/dL: 21%
   46.1
Serum Alanine aminotransferase (ALT) 15 20  27.48
Serum Aspartate aminotransferase (AST) 15  20  16.69
Serum Bilirubin (total) 21 ± 0.4 mg/dL or ± 20% (greater)   26.94
Serum Calcium 10 ± 1.0 mg/dL  2.55
Urine Calcium 18    
Serum Carcinoembryonic antigen (CEA) 16    24.7
Serum Chloride 7 5 1.5
Urine Chloride 14    
Serum Cholesterol 8.5  10 9.01
Serum HDL-cholesterol 15  30 11.63
Serum Cholesterinase 12   9.8
Serum Cortisol 16 25 22.8
Serum Creatinine kinase (CK) 21 30 30.3
Serum Creatinine 15 ± 0.3 mg/dL or ± 15% (greater)  8.87
Urine Creatinine 21    28.4
Serum Digoxin 30 ± 20% or ± 0.2 ng/mL (greater)   
Blood Erythrocytes 7  6 4.4
Serum Estradiol up to 200 pmol/L:
44 pmol/L
> 200 pmol/L: 22%
   26.86
Serum Ferritin 24   16.9
Serum γ-Glutamyl transferase (GGT) 15   22.11
Serum Glucose 9 ± 6 mg/dL or ± 10% (greater)   6.96
Urine Glucose 22    
Blood Hematocrit 10 6 3.97
Blood Hemoglobin 6  7  4.19
Blood Hemoglobin A1c 18   3
Serum Immunogobulin A (IgA) 20 ± 3 SD  13.5
Serum  Immunogloblin G (IgG) 18  25  8.0
Serum Immunogloblin M (IgM) 21  ± 3 SD  16.8
Serum Iron 15 20 30.7
Serum Lactate 15   30.4
Serum Lactate dehydrogenase (LDH) 21 20  11.4
Blood Leukocytes 9 15  15.49
Serum Lipase 24   37.88
Serum Lithium 12 ± 0.3 mmol/L or ± 20% (greater)   
Serum Magnesium 15 25 4.8
Blood Mean corpuscular volume (MCV) 70   2.42
Serum Phenobarbital 20 20  
Serum Phenytoin 20  25  
Serum Phosphate 15    10.11
Urine Phosphate 18    22.1
Serum Potassium 8 ± 0.5 mmol/L   5.61
Urine Potassium 17   28.4
Serum Progesterone 20    
Serum Protein 9 10 3.63
Urine Protein up to 1 g/L:
0.24 g/L
> 1 g/L: 24%
  40.0
Plasma Prothrombin time (PTr), ratio 20    
Serum Sodium 5 ± 4 mmol/L  0.73
Urine Sodium 11   32.0
Serum Testosterone 22   13.61
serum Thriiodothyronine (Total T3) up to 1.5 nmol/L:
0.225 nmol/L
> 1.5 nmol/L: 15%
± 3 SD  12.94
Serum Thyrotropin (TSH) 14 ± 3 SD  23.7
Serum Total prostatic specific antigen (PSA) 15   33.6
Serum Throxine,  Free (FT4) 13 ± 3 SD  8.0
Serum Total thyroxine (TT4) 13 ± 3 SD   7.0
Serum Triglycerides 15 25  25.99
Serum Urate 14 17 11.97
Urine Urate 17   19.39
Serum Urea 15 ± 2 mg/dL or ± 9% (greater)  15.55
Urine Urea 26   22.1

As we've seen with other comparisons recently, the truth about the CLIA goals is that they are still relevant. CLIA performance specifications are often criticized as being too old or too wide, yet they are freuquently similar to these Dmax goals, which are built on today's actual method performance. Meanwhile, the differences between the Dmax goals and the desirable biologic TEa specifications are more significant.