Costa Rican experience in the external quality assessment program for serum lipids analysis

The analysis of the lipid profile is fundamental in the valuation of atherosclerotic illness. For this reason, the necessity of implementing ail external quality assessment program in lipids determination that offers a real orientation about the accuracy of the methods used for analysis of total cholesterol, triglycerides and HDL-cholesterol (high density lipoprotein), was determined. Costa Rica began in 1995 the "External quality assessment program" with 32 laboratories of the metropolitan area. By now, 110 laboratories of different areas of the country participate: 79% of the public sector and 21% of the private sector. The control material is frozen fresh human serum, aseptically packed and distributed with dry ice to reduce the matrix effect. The designated value establishes ill reference laboratories, 4 to 5 voluntary surveys per year are carried out and the answer fluctuates between 89.5% and 95.4% of the participants. The average rate of acceptable laboratories was between 61.4% and 82.7% for total cholesterol, 68.2% and 80.4% for triglycerides and 51.1% and 85.5% in the case of the HDL-cholesterol. The interlaboratory average variation coefficients that came across were 7.2% and 9.2%, 10.9% and 14.1% and 15.2% and 31.4% for total cholesterol, triglycerides and HDL-cholesterol, respectively, being notorious the decrease of this variation in HDL-cholesterol during the years 2000 and 2001.