Whither Westergren--the sedimentation rate reevaluated

The term "Westergren sedimentation rate" implies that a standardized test is being performed. Questionnaires sent to 177 rheumatologists and 150 clinical laboratory directors showed that a variety of techniques are used to perform the sedimentation rate by the "Westergren" method. A comparative study revealed that the most reproducible results could be obtained with the classical Westergren technique or with a modified Westergren technique using EDTA anticoagulated blood and saline diluent. The use of undiluted whole blood in a Westergren tube was less reproducible and compared poorly with the classical Westergren technique. The results confirm that the undiluted Westergren technique should not be used and that in clinical studies the technique employed for determining the sedimentation rate should be specified.