Red Cell Volume Distribution Width Standard Deviation

**Semantic type:** Laboratory Procedure

**Definition:** A measurement of the volume dispersion within a red blood cell population, calculated as the width of the distribution curve at the 20% frequency level.

**Synonyms:** - Erythrocyte Distribution Width Standard Deviation - RDW Standard Deviation - RDW Standard Deviation - RDW Standard Deviation - RDW-SD - RDWSD