Economical Analysis of Implementation of External Quality Controls in a General Hospital Hematology Laboratory.

Introduction: The Spanish rule UNE-EN ISO 15189 concerning to Clinical Laboratory establish the realization of external quality controls (EQC) in order to compare results between laboratories. In 2004, external quality controls programs were initiated in our laboratory provided by the AEHH and SEQC.

Aim: To analyze the increase of cost in each determination when we apply these quality measures.

Material and methods: Period of study January 2004– December 2004. Encoded information obtained from ModulabWin informatics system. Determinations provided by AEHH: general hematology (RBC, Hb, HTC, MCV, MHC, HMCC, WBC, reticulocytes, cellular morphology, platelets, protrombine time, partial tromboplastine time, fibrinogen) AT III, F VIII, Hb A2 and F, automated reticulocytes, activated protein C resistance, differential count of WBC: (neutrophiles, monocytes, lymphocytes, eosinophils, basophiles), erythrocyte sedimentation rate (ESR). Determinations provided by SEQC: total proteins, albumin, complement C3 and C4, IgA, IgG, IgM, transferrine, iron serum levels, haptoglobine, ferritine, reactive protein C, b 2-microglobuline. For each ECQ with only one specimen for a unique determination the increase of costs was calculated as follow: EQC cost / total number of determinations. For each EQC with more than one determination the increase of costs was calculated as follow: (EQC cost / total number of parameters)/ total number of determinations.

Results: In ECQ with only one specimen for a unique determination, the increase of cost for each determination was ESR: 0.0033€, AT III: 0,1051€, FVIII: 1.79€, automated reticulocytes: 0,0334€, differential count of WBC 0,0033€. In EQC with more than one determination the increase of cost: were: Albumin and total proteins 0,0030€; C3 and C4: 0,0473€; activated protein C resistance: 0,0059€; IgA, IgG, IgM and b-2 microblobuline: 0,0030€; iron serum levels, Transferrine and Ferritine: 0,0025€; Haptoglobine: 0,0057€; RBC, Hb, HTC MCV, MHC, HMCC, WBC, platelets: 0,0003€ and for protrombine time, partial tromboplastine time and fibrinogen: 0,0007€.

Conclusions: The EQC for F VIII has been the more expensive control related to the number of determinations, however it is justified because our laboratory is reference center for the area. The incorporation of EQC hardly has increase the global costs of different determinations in a General Hematology Laboratory, nevertheless the quality, reproducibility, validity and security of results obtained with this procedure justify the slight increase of costs. This work has been partially supported by a grant from Aragon Health Service.