Portal de Periódicos da CAPES

Comparison of Procedures for Evaluating Laboratory Performance in External Quality Assessment Schemes for Lead in Blood and Aluminum in Serum Demonstrates the Need for Common Quality Specifications

2002; American Association for Clinical Chemistry; Volume: 48; Issue: 11 Linguagem: Inglês

10.1093/clinchem/48.11.2000

1530-8561

Andrew Taylor, J. Angerer, F Claeys, Jesper Kristiansen, Olav Mazarrasa, Antonio Menditto, Marina Patriarca, Alain Pineau, Ilse Schoeters, Christophe Sykes, Sinikka Valkonen, Cas Weykamp,

Health Systems, Economic Evaluations, Quality of Life

Abstract Background: The different scoring methods used by eight European External Quality Assessment Schemes (EQASs) for occupational and environmental laboratory medicine were compared to develop suitable quality specifications as a step toward harmonization. Methods: Real results for blood lead and serum aluminum assays, reported by participants in Italian and United Kingdom EQASs, were evaluated according to individual scheme scoring criteria. The same results were then used to produce z scores using scheme-based between-laboratory SDs as the estimate of variability to determine whether simple performance-derived quality specifications produced better agreement among schemes. Results: The schemes gave conflicting assessments of participants’ performance, and participants judged to be successful by one scheme could be defined as performing inadequately by another. An approach proposed by Kenny et al. (Scand J Clin Lab Invest 1999;59:585), which uses clinical inputs to set targets for analytical imprecision, bias, and total error allowable, was then used to elaborate quality specifications. Conclusions: We suggest that the CLIA ′88 recommendations for blood lead (± 40 μg/L or ± 10% of the target concentration, whichever is the greater) could be used as a quality specification, although a revision to ± 30 μg/L or ± 10% is recommended. For serum aluminum, a suitable quality specification of ± 5 μg/L or ± 20% of the target concentration, whichever is the greater, is suggested. These specifications may be used to compare laboratory performance across schemes.