Purpose: A study was conducted to develop a model to identify adverse drug events (ADEs) and quantify their effect on quality and cost in a large tertiary care hospital.
Methods: The drug-ADE relationship between unfractionated heparin and heparin-induced bleeding was studied for all inpatients receiving heparin infusions at the hospital between January 1 and December 31, 2004. Activated partial thromboplastin time (aPTT) values were used to help determine if the patients received blood products in response to excessive anticoagulation with heparin. The number of aPTT values of > or =150 seconds and the last aPTT value before discharge were evaluated. The key outcome measures were length of stay, cost per admission, and mortality. Of the 1455 admissions to the hospital, 122 patients received blood products before receiving heparin infusion only, 264 received blood products after receiving the drug only, 221 received blood products both before and after, and 848 who received the drug never received blood products.
Results: Differences in full cost and length of stay between the group receiving heparin infusion only and the groups receiving both blood products were significant. Differences in mortality between the group only receiving heparin infusion and the groups receiving both heparin infusion and blood products were also significant.
Conclusion: Using the model developed to study the effect of heparin-induced bleeding, we found that the cost per patient day was highest for patients receiving blood products after heparin infusion treatment. There was a positive correlation between one or more aPTT values of > or =150 seconds and undesirable patient outcomes.