Preanalytical quality control program - an overview of results (2001-2005 summary)

Background: Preanalytical variables, such as sample collection, handling, transport, and storage, may affect patient results. The number of errors in the preanalytical phase may decrease by following standardized procedures. Methods: A retrospective analysis (2001-2005) of results obtained through the Spanish Society of Clinical Chemistry and Molecular Pathology Quality Assessment Program for the Preanalytical Phase has been carried out to summarize data regarding the main factors affecting the preanalytical phase quality. In such a program, participants are asked to register rejections and causes for rejection of routine or stat samples usually and locally collected at their laboratories. Results: Results discussed refer to 105 laboratories. Of the 4,715,132 tubes expected to be received during the data collection period among participating laboratories and according to determinations included by clinicians in the request form, 32,977 (0.699%) offered a cause for rejection. Whole blood-EDTA samples and serum samples accounted for 75.6% of all samples collected among laboratories, although they only corresponded to 55.8% of all registered rejections. In total, 81% of rejections arose as a result of the following reasons: specimen not received (37.5%), hemolysis (29.3%), and clotted sample (14.4%). Moreover, plasma-citrate-erythrocyte sedimentation rate exhibited the highest percentage of rejection (1.473%), whereas the lowest rate corresponded to whole blood-EDTA (0.381%). Conclusions: Overall percentage of rejection is similar to previously published data. As some of the included variables have turned out to be irrelevant, the program has been simplified from the year 2006 onwards.