The Marginal Costs of Adverse Drug Events Associated With Exposures to Anticoagulants and Hypoglycemic Agents During Hospitalization.

BACKGROUND: Anticoagulants and hypoglycemic agents are 2 of the most challenging drug classes for medical management in the hospital resulting in many adverse drug events (ADEs).
OBJECTIVE: Estimating the marginal cost (MC) of ADEs associated with anticoagulants and hypoglycemic agents for adults in 5 patient groups during their hospital stay and the total annual ADE costs for all patients exposed to these drugs during their stay. RESEARCH DESIGN AND SUBJECT: Data are from 2010 to 2013 Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases and Medicare Patient Safety Monitoring System (MPSMS). Deidentified patients were linked using probabilistic matching in the same hospital and year for 5 patient groups. ADE information was obtained from the MPSMS using retrospective structured record review. Costs were derived using HCUP cost-to-charge ratios. MC estimates were made using Extended Estimating Equations controlling for patient characteristics, comorbidities, hospital procedures, and hospital characteristics. MC estimates were applied to the 2013 HCUP National Inpatient Sample to estimate annual ADE costs.
RESULTS: Adjusted MC estimates were smaller than unadjusted measures with most groups showing estimates that were at least 50% less. Adjusted anticoagulant ADE costs added >45% and Hypoglycemic ADE costs added >20% to inpatient costs. The 2013 hospital cost estimates for ADEs associated with anticoagulants and hypoglycemic agents were >$2.5 billion for each drug class.
CONCLUSIONS: This study demonstrates the importance of accounting for confounders in the estimation of ADEs, and the importance of separate estimates of ADE costs by drug class.