ICSH recommendations for modified and alternate methods measuring the erythrocyte sedimentation rate.

INTRODUCTION

The gold standard for the determination of the erythrocyte sedimentation rate (ESR) is the Westergren method. Other methods to measure the ESR have become available. They range from modest modifications of the Westergren method to very different methodologies. The ICSH therefore established a Working Group to investigate these new approaches and compile recommendations for their validation and verification.

METHODS

A panel of six experts in laboratory hematology examined the peer-reviewed literature and EQA surveys from over 6000 laboratories on four continents performing ESR testing. This information was used to create lists of ESR instrument manufacturers and their methods.

RESULTS

Only 28% of laboratories surveyed used the unmodified Westergren method, while 72% of sites used modified or alternate methods. Results obtained with the new instruments could differ from results obtained with the Westergren method by up to 142%. Different non-Westergren methods showed differences from each other of up to 42%. The new methods were often significantly faster, safer, and less labor-intensive. They reduced costs and often used standard EDTA tubes, eliminating the need for a dedicated ESR tube.

CONCLUSION

Based on the consensus of the Working Group, recommendations for manufacturers for the validation of new ESR methods were developed. In addition, a list of recommendations for laboratories that are moving to modified or alternate methods was compiled, addressing instrument performance verification and communications of results to clinical users.