Diagnostic accuracy and clinical utility of a simplified low cost method of counting CD4 cells with flow cytometry in Malawi: diagnostic accuracy study

In this paper by Calman A MacLennan and colleagues, we gave the wrong unit for the CD4 cell count (BMJ 2007;335:190-4, 28 Jul, doi: 10.1136/bmj.39268.719780.BE). Throughout the article we gave the unit as ×10⁹/l, whereas the correct unit is cells/µl (cells per microlitre). This error has been corrected in the online pdf and html versions of the article.