Matzek LJ, Hanson AC, Schulte PJ, et al. - This observational cohort study was undertaken to determine the prevalence as well as the clinical significance of preoperative thrombocytopenia among adults undergoing elective surgery with planned postoperative hospitalization, with thorough consideration of preoperative anemia status. Four groups were defined: normal platelet and hemoglobin levels, isolated thrombocytopenia (ie, platelet count < 100 × 10 ⁹ /L), isolated anemia (ie, hemoglobin <12 g/dL women, <13.5 g/dL men), and thrombocytopenia with anemia. In those with concurrent anemia, but not in those with normal preoperative hemoglobin levels, longer hospital length of stay was reported in relation to thrombocytopenia. Elevated odds for intraoperative transfusion were observed in relation to thrombocytopenia; this was evident irrespective of anemia status. Findings revealed an association of preoperative thrombocytopenia with clinical results in elective surgery, both in the presence as well as absence of concurrent anemia. However, the presence of isolated thrombocytopenia was rare (0.5%) and was usually detected prior to preoperative testing. Routine thrombocytopenia screening is unlikely to be indicated for most patients.