Outcomes associated with observation stays versus inpatient admissions for pulmonary embolism.

Changes in reimbursement policies have led to an increased use of observation stays in the United States (US). We sought to compare outcomes among pulmonary embolism (PE) patients managed through observation stays or inpatient admissions.The Premier Perspective Comparative Hospital Database was used to identify patients with a primary International Classification of Diseases, ninth-edition diagnosis of PE (415.1×) from 11/2012-3/2015. Patients were required to have claims for ≥1 diagnostic tests for PE on days 0-2 and evidence of PE treatment. Patients managed through observation stays were 1:1 propensity score matched to those undergoing inpatient admissions. We compared length-of-stay (LOS), hospital costs (2015US$) and rates of hospital-acquired conditions and readmission between the cohorts. A total of 1105 PE observation stays were matched to 1105 inpatient admissions. The baseline characteristics of the cohorts were well-balanced (no standardized differences >10 %). Mean ± standard deviation LOS and hospital costs were 3.6 ± 2.6 days and $5423 ± $5770, respectively. LOS was shorter for observation stays 2.3 ± 1.3 days) vs. inpatient admissions (4.9 ± 3.0 days, p < 0.001). This corresponded to a mean $4390 lower treatment costs for observation stays (p < 0.001). Hospital-acquired conditions were less common among observation stay patients vs. inpatients (p < 0.001); driven predominantly by reductions in bacterial pneumonia and Clostridium difficile infection. Readmission for venous thromboembolism or major bleeding in the same or subsequent 2-months did not differ between the cohorts (p ≥ 0.16 for both).Compared with inpatient admissions, observation stays were associated with reduced LOS, costs and hospital-acquired conditions, without increased risk of readmission.