METHOD VALIDATION STUDY TO EVALUATE THE ANALYTICAL PERFORMANCE OF THE STAT–SITE METER FOR THE MEASURMENT OF SERUM BETA-HYDROXYBUTRATE

Objectives: To evaluate the analytical performance of the STAT-Site meter (Stanbio laboratory USA) for the measurement of serum beta-hydroxybutyrate (? OH-B) concentration. Methods: The precision was evaluated using two levels of quality control materials (low and high). Within run and between run precision studies were performed. CVs (coefficient of variation) compared against accepted standards. Fifty-one leftover patient samples with previously reported ? OH-B concentrations were used for the method comparison. The accuracy was evaluated and compared to our current laboratory method, (Wako Autokit 3-HB, Wako chemical USA). Slope, intercept, correlation coefficient, Deming regression and paired t-test were calculated using Analyse-it® software Results: The meter showed reasonable precision for the measurement of ? OH-B with CV of 0.0% and 6% for within run precision study and 8.82% and 10.07% for between run precision study which are acceptable according to two CAP surveys. Further these are comparable to our current method CV and the manufacturer claimed CV’s. Deming regression analysis showed a linear relationship between the two methods: The slope of the regression equation was 0.98 (95% CI, 0.87-1.08); intercept 0.10 (95% CI 0.03-0.16) and correlation coefficient of 0.979.There was no bias detected by the visual inspection of the difference plot, this was confirmed by the calculation of the paired t-test (p = 0.19). Conclusion: The STAT-Site meter is a practical, rapid method with wide analytical range that meets precision and accuracy criteria. The method is suitable for the use in a research context until it gets approval for clinical use