Risks and cost burden of venous thromboembolism and bleeding for patients undergoing total hip or knee replacement in a managed-care population

Abstract

Background:

Total hip and total knee replacement (THR/TKR) patients are at increased risk of developing venous thromboembolism (VTE). VTE prevention using anticoagulation therapy increases the risk of bleeding. Therefore, any assessment of the cost of VTE and its prevention should also take into consideration risks and costs of bleeding.

Objective:

To assess the risks of developing VTE and bleeding in patients after THR or TKR given real-world use of thromboprophylaxis, and to quantify the incremental cost associated with each.

Methods:

Analyses of insurance healthcare claims from the Ingenix IMPACT National Managed Care Database^TM from January 2004 to December 2008 were conducted. Subjects were ≥18 years and had ≥1 procedure code for THR or TKR. Patients had to have ≥180 days of observation prior to surgery and were observed for ≤3 months after THR or TKR. VTE was defined as ≥1 diagnosis code for deep vein thrombosis or pulmonary embolism. Bleeding events were classified as major or non-major. Risks of VTE or bleeding events were calculated as number of patients with an event divided by number of patients with the procedure. Incremental all-cause healthcare costs associated with VTE or bleeding were calculated as the difference between cohorts of patients without VTE or bleeding matched 1:1 to patients with VTE or bleeding.

Results:

Of 119,729 patients (43,670 THR and 76,059 TKR), 7974 had a VTE event and 4849 had a bleeding event (2216 major bleeding [a subset of ‘any bleeding’]). The risks of VTE, any bleeding, and major bleeding were 6.7, 4.0, and 1.9 events, respectively, per 100 patients. Up to 3 months after THR/TKR, mean incremental all-cause healthcare costs per patient per month associated with VTE, bleeding, and major bleeding were $2729, $2696, and $4304, respectively. Total monthly costs versus matched controls over 3 months were: VTE: $12,333 vs. $9604; any bleeding: $12,481 vs. $9785; major bleeding: $14,015 vs. $9710; p < 0.001 for all.

Limitations:

Key limitations included potential inaccuracies or omissions in procedures, diagnoses, or costs of claims data; lack of information on the amount of blood transfused or decreases in the hemoglobin level to evaluate the severity of a bleeding event; and potential biases due to the observational design of the study.

Conclusion:

From the managed-care population perspective, in THR/TKR patients the greater incidence of VTE compared to any bleeding and major bleeding translated into a higher cumulative cost burden.

Key words::

• Bleeding
• Costs
• Risks
• Total hip replacement
• Total knee replacement – Venous thromboembolism

Transparency

Declaration of funding

This research was funded by Ortho-McNeil Janssen Scientific Affairs, LLC, Raritan, NJ, USA.

Declaration of financial relationships

Five of the authors (F.V., F.L., M.S.D., K.D., and P.L.) are employees of Analysis Group, Inc., a consulting company that has received research grants from Ortho-McNeil Janssen, and four of the authors (J.C.L., B.K.B., J.S., and W.H.O.) were employees of Ortho-McNeil Janssen at the time that the study was conducted. Four of the authors own stock in Johnson & Johnson (J.S., B.K.B., J.C.L., W.H.O.). E.N. received research grants from Ortho-McNeil Janssen Scientific Affairs, LLC, Raritan, NJ, USA.

This contribution represents original work, has not been previously published or simultaneously submitted for publication elsewhere. This manuscript has been read and approved by all the authors, and all conditions stated by the International Committee of Medical Journal Editors have been met.

Acknowledgments

The authors would like to acknowledge Ruth Sussman, PhD, for editorial assistance in the preparation of this manuscript with funding from Ortho-McNeil Janssen Scientific Affairs, LLC.

Parts of this work were presented as posters at the Academy of Managed Care Pharmacy (AMCP) 22nd Annual Meeting and Showcase, April 7–10, 2010, San Diego, California and the 2010 Summer Meeting of the American Society of Health-System Pharmacists, June 6–9, 2010 Tampa, Florida, USA.