Etiology and complications of thrombocytopenia in hospitalized medical patients.

To determine incidence, risk factors, hematologic complications, and prognostic significance of thrombocytopenia in the general medicine population, we performed a single-institutional, retrospective study of all adult patients admitted to a general medical ward from January 1st, 2014 to December 31st, 2014 with hospital-acquired thrombocytopenia. Those with moderate thrombocytopenia, defined as a platelet count nadir of <100 × 10^9/L and/or a >50% relative decline, were compared to those with less severe thrombocytopenia. Of the 7420 patients admitted, 465 (6.3%) developed hospital-acquired thrombocytopenia. Infection and moderate thrombocytopenia were present in 56 and 23%, respectively. Severe sepsis and antibiotic use were both associated with moderate thrombocytopenia, and proton pump inhibitor use was statistically significant in both univariate and multivariate analysis. Hematologic complications were more frequent with moderate thrombocytopenia, including frequency of HIT testing and red blood cell transfusions. Outcome metrics including transfer to an intensive care unit (OR 6.78), death during admission (OR 6.85), and length of stay (10.6 vs. 5.1 days) were all associated with moderate thrombocytopenia. Thrombocytopenia is associated with poor prognosis, and the association between moderate thrombocytopenia and proton pump inhibitor use is relatively novel and should be validated in prospective studies.