1. Thrombocytopenia definitely caused by drug. Inclusion criteria 1 and 4 met.
  2. Thrombocytopenia probably caused by drug. Inclusion criteria 2 and 4 met.
  3. Thrombocytopenia possibly caused by drug. Inclusion criteria 3 met.
  4. Thrombocytopenia unlikely caused by drug. Inclusion criteria 1 or 2 met, but criterion 4 not met.
  5. Excluded. (See reason for exclusion below.)


1.      The study was a prospective, randomized controlled trial.

2.      The study was a prospective cohort with a control group, not randomized.

3.      The study was a retrospective case control study or cohort study with a control group, or a prospective cohort study without a control group or a retrospective case series.

4.      There was significantly greater frequency of thrombocytopenia in patients treated compared to patients not treated with the suspected drug.


1.      Insufficient clinical data with which to evaluate the relationship between drug administration and thrombocytopenia

2.      Platelet count of 100,000 cells/mL or more

3.      Agents that cause thrombocytopenia due to marrow suppression (i.e. chemotherapy, valproate, linezolid, penicillamine)

4.      Agents that cause thrombocytopenia due to accelerated clearance of platelets (i.e. porcine factor VIII or Desmopressin in patients with 2B VWD)

5.      Agents that cause sustained TCP without marrow suppression (possible ITP; i.e. MMR, G-CSF, Alemtuzumab)

6.      Patient exposed to nontherapeutic agent or experimental agent or used an agent in a nontherapeutic manner

7.      Drug-induced disease includes things other than thrombocytopenia

8.      Neonatal thrombocytopenia that was attributed to a drug taken by the mother