Absolute RP counts (RP% × platelet count) in chronic thrombocytosis patients (A) before and after treatment with aspirin (•) and (B) at baseline and follow-up in untreated chronic thrombocytosis patients (⧫). Initial (baseline) values were drawn at enrollment into the study; follow-up studies were drawn at the first new visit after enrollment. The interval between studies ranged from 4 to 23 weeks and 7 to 30 weeks in treated and untreated subjects, respectively.