Ac. Browning et al., Comparison of the erythrocyte sedimentation rate measured in the eye casualty department by the Seditainer method with an automated system, EYE, 13, 1999, pp. 754-757
Purpose To compare a new automated system for the measurement of erythrocyt
e sedimentation rate (ESR) with the established manual Seditainer method.
Methods Two hundred and twelve patients undergoing investigation for giant
cell arteritis or other systemic vasculitides had ESR measurements by both
the established manual Seditainer and the new laboratory-based automated sy
stem. The results were compared by correlation coefficient and mean differe
nce. The limits of agreement with confidence intervals were also calculated
.
Results Across the range of results from 1 to 120 mm/h, the correlation coe
fficient was 0.844. The automated method had a mean negative bias of -9.8 m
m/h (95% confidence interval: -12.2 to -7.4 mm/h). The wide scatter of resu
lts produced limits of agreement (+/- 2 standard deviations) between the tw
o methods of -45 to 26 mm/h. There were seven results that were underestima
ted by the automated system which were clinically significant.
Conclusions There is a wide degree of scatter between the two sets of resul
ts. The automated system has a negative bias when compared with the manual
method. There is a propensity for the automated system to sporadically unde
restimate the hue result, sometimes to a degree that is clinically signific
ant. The authors therefore cannot recommend replacement of the manual Sedit
ainer system at the present time.