Examination of the validity and reliability of the Accusport blood lactate analyser.

Clough et al. (1997) reported that 95% of lactate values obtained using an Accusport analyser may be up to 2.6 mM below or 2.1 mM above YSI 2300 analyser values over the range 0-16 mM. This variability is substantial and unsuitable for research purposes, The objectives of this study were to re-examine the specific validity and reliability of an Accusport analyser and to develop a regression equation to improve the accuracy of Accusport measurements. Duplicate measurements of lactate concentration were made on both an Accusport (Boehringer Mannheim) and Analox LM3 Multi Channel analyser on 17 blood samples taken from two subjects performing a discontinuous incremental exercise protocol. Analysis of duplicate measurements revealed good test-retest reliability for Accusport (TEM 0.35 mM; SEM 0.24 mM; ICC r = 0.995) and Analox (TEM 0.07 mM; SEM 0.09 mM; ICC r = 0.999). The mean values for duplicate samples recorded on both the Accusport and Analox between the lactate range of 1-13 mM revealed an average difference between the two analysers of 1.7 mM (P< 0.01, range 1.0-2.9 mM) but values demonstrated a high level of association (ICC r = 0.853; P< 0.05). The level of agreement indicated that in 95% of cases the differences would lie between + 0.5 to + 3.0 mM with the Accusport values always higher than Analox. Linear regression analysis calculated the following equation to predict Analox values from Accusport values: Analox = -0.749 + 0.837Accusport (R2 = 0.990). The results showed the portable Accusport analyser to be reliable and it demonstrated good association with Analox LM3 lactate analyser measures. However, a need exists to develop specifically generated regressions from Accusport and Analox LM3 analyser measures to provide more accurate results when interpreting lactate values from Accusport measures taken in the field.