We searched for articles using both electronic and hand searching. In March 2007, we searched the MEDLINE® and EMBASE databases. We repeated the search in May 2007, adding a supplemental search targeting thrombocythemia. On June 30, 2007, the MEDLINE® and EMBASE® searches were updated and additional searches were executed using TOXLine and CINAHL. All searches were limited to English-language articles involving treatment of humans. Review articles were excluded from the searches. Searches were not limited by date of publication or subject age. .
