NORIP, Malmø 27/4-2004

NORIP concept Common Nordic Reference Intervals NFKK meeting 27/ Pål Rustad Fürst Medical Laboratory, Oslo

NORIP, Malmø 27/ Content NORIP concept Reference samples Reference materials (controls) Measurement Calculation of reference intervals Results Documentation Spinoff effects

NORIP, Malmø 27/4-2004

NORIP concept 102 labs participated –Each lab collected samples from >25 ref. individuals evenly distributed on gender and age and froze at -80 °C –Lab received controls CAL, X, P, HIGH, LOW on dry ice –Lab measured ref. samples and controls in one series 10 CAL and 3 of each of the other –Lab submitted –reference samples for storage in bio-bank (NOBIDA) –data on reference individual, measurement system and measurements Reference intervals were calculated centrally

NORIP, Malmø 27/ Reference samples Inclusion criteria The reference individual should  be feeling subjectively well  have reached the age of 18  not be pregnant or breast-feeding  not been an in-patient in a hospital nor been subjectively dangerously ill during the last month  not had more than 2 measures of alcohol (24 g) in the last 24 hours  not given blood as a donor in the last five months  not taken prescribed drugs other than the P-pill or estrogens (female sex hormone) during the last two weeks  not smoked in the last hour prior to blood sampling

NORIP, Malmø 27/ Preanalytical conditions Reference individual –Sitting at least 15 min before sampling Sample collection –Li-heparin plasma or serum, EDTA-blood for haematology –Standard procedure –Minimal stasis Sample handling (plasma and serum) –Stored in the dark –Storage in room temperature before centrifugation serum: h, plasma: max 15 min –Centrifugation: 10 min at min 1500 g –Distributed to secondary tubes within 2 h –Stored at -80 °C within 4 h

NORIP, Malmø 27/ Controls Commutability and traceability Commutability –CAL, X and P prepared from fresh donors blood collected in dry bags and allowed to coagulate pooled, filtered, mixed dispensed in polypropylene vials frozen at –80  C without further processing –HIGH, LOW HIGH: Pool concentrated ~1.3 times by a freeze-drying procedure LOW: HIGH diluted 1:2 by a sodium/calcium solution Traceability to reference methods Exceptions non-enzymes: HDL cholesterol, TIBC (enzymes: ALP, AMY, AMY-P, AST, LD)

NORIP, Malmø 27/ Controls Target values Comparison DGKC 1997/2002 and Nordic Trueness Project 2002

NORIP, Malmø 27/ Transferred values Deviation from reference method values

NORIP, Malmø 27/ Creating the data pool of reference values –Correction by CAL for non-enzymes –Exclusions methods (non IFCC for enzymes etc.) reference individuals quality goals (no exclusions) large differences between materials –i.e. thawed serum against fresh serum for a reference individual reduction of biological variation –CK (physical activity) –Glucose (fasting, diabetes in family) –Triglyceride (fasting)

NORIP, Malmø 27/ Measurement Instrument manufacturers

NORIP, Malmø 27/ Measurement systems Deviation for corrected controls

NORIP, Malmø 27/ Effect of correction Calcium: Mean of lab. reference values

NORIP, Malmø 27/ Comparison of distributions of not corrected and corrected ref. values Reference interval: mmol/L

NORIP, Malmø 27/ Calculation of reference intervals Nonparametric 2.5 and 97.5 percentiles Partitioning 4.1% of subpopulation outside common reference limit –Gender –Age Age limit(s) decided by investigating reference limits for each decade (18-29, 30-39, 40-49, 50-59, 60-69, >70 years)

NORIP, Malmø 27/ Reference intervals non-enzymes

NORIP, Malmø 27/4-2004

Reference intervals Enzymes

NORIP, Malmø 27/ Reference intervals Haematology 1800 ref. individuals from mainly Finland and Sweden

NORIP, Malmø 27/ Documentation NORIP home site Klinisk Biokemi i Norden, no 2, 2003 Clinical Chemistry and Laboratory Medicine (CCLM), in press Scandinavian Journal of Clinical and Laboratory Investigation (SJCLI), in press

NORIP, Malmø 27/ SJCLI 1. The Nordic Reference Interval Project recommended reference intervals for 25 common biochemical properties 2. Prerequisites for Establishing Common Reference Intervals 3. Minimally processed fresh frozen human reference sera. Preparation, Testing, and Application to International External Quality Assurance 4. The Nordic Trueness Project 2002 – Use of Reference Measurement Procedure Values in a General Clinical Chemistry Survey 5. Certificate of analysis: NFKK Reference Serum X - a reprint 6. Reference individuals, sampling conditions and treatment of samples in the Nordic Reference Interval Project for routine clinical biochemical properties 7. Descriptive analytical data and consequenses for calculation of common reference intervals in the Nordic Reference Interval Project Reference intervals for eight enzymes in blood of adult women and men measured in accordance with the IFCC reference system at 37°C - A part of the Nordic Reference Interval Project A multicenter study of reference intervals for haemoglobin, basic blood cell counts and etythrocyte indices in the adult population of Nordic countries 10. Effect of analytical quality on establishing the common reference intervals and their use 11. Are the Common Reference Intervals Truly Common? Case Studies on Stratifying Biochemical Reference Data by Countries Using Two Partitioning Method 12. Nordic Reference Interval Project Bio-bank and Database (NOBIDA). A source for future reference interval estimation and retrospective evaluation 13. Letter: Creatininium reference intervals for corrected methods

NORIP, Malmø 27/ Spinoff effects Trueness verification with NFKK Reference serum X –Local –Measurement system manufacturers Roche, Ortho (Vitros), Abbott, Konelab Creatinine –Ortho (Vitros) back to reference method level –Creatinine-free serum from EQUALIS NFKK projects? –Reference limits contra decision limits –Reference limits for children