Platelet function tests, independent of platelet count, are associated with bleeding severity in ITP.
Frelinger AL, Grace RF, Gerrits AJ, Berny-Lang MA, Brown T, Carmichael SL, Neufeld EJ, Michelson AD. Platelet function tests, independent of platelet count, are associated with bleeding severity in ITP. Blood. 2015 Aug 13; 126(7):873-9.