CLINICAL RESEARCH STUDY Adherence to Pharmacological Thromboprophylaxis Orders in Hospitalized Patients John Fanikos, RPh, MBA, a Leslie Ann Stevens, BS, b Matthew Labreche, b Gregory Piazza, MD, b Elaine Catapane, MEd, MT (ASCP), c Lena Novack, PhD, c Samuel Z. Goldhaber, MD b a Department of Pharmacy, Brigham and Women’s Hospital, Boston, Mass; b Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Mass; c Harvard Clinical Research Institute, Harvard Medical School, Boston, Mass. ABSTRACT OBJECTIVE: We compared adherence to unfractionated heparin (UFH) 2 or 3 times daily prophylaxis orders versus low-molecular-weight heparin (LMWH) once daily orders. Our goals were to determine which strategy demonstrated the best adherence in terms of timing and frequency of dose administration, and to determine reasons for ordered heparin not being administered. METHODS: We queried our electronic medication administration record where nurses document reasons for delayed administration or omitted doses. We identified 250 consecutive patients who were prescribed prophylaxis with UFH 2 or 3 times daily or LMWH once daily. We followed patients for their hospital- ization to determine adherence to physicians’ prophylaxis orders. RESULTS: Adherence, defined as the ratio of prophylaxis doses given to doses ordered, was greater with LMWH (94.9%) than UFH 3 times daily (87.8%) or UFH twice daily (86.8%) regimens (P .001). Patients receiving LMWH more often received all of their scheduled prophylaxis doses (77%) versus UFH 3 times daily (54%) or UFH twice daily (45%) (P .001). There were no differences between regimens regarding reasons for omitted doses. The most common reason for late or omitted doses was patient refusal, which explained 44% of the UFH and 39% of the LMWH orders that were not administered. CONCLUSIONS: LMWH once a day had better adherence than UFH 2 or 3 times daily. For both LMWH and UFH, patient refusal was the most common reason for not administering prophylaxis as prescribed. These findings require consideration when evaluating pharmacological prophylaxis strategies. Educational programs, explaining the rationale, may motivate patients to improve adherence during hospitalization. © 2010 Elsevier Inc. All rights reserved. • The American Journal of Medicine (2010) 123, 536-541 KEYWORDS: Low-molecular-weight heparin; Medication adherence; Prophylaxis; Unfractionated heparin; Venous thromboembolism The Surgeon General has cited venous thromboembolism as the most common preventable cause of in-hospital death. 1 The Centers for Medicare and Medicaid Services 2 and The Joint Commission 3 have made elimination of hospital-ac- quired deep vein thrombosis and pulmonary embolism a critical patient safety issue. While multiple pharmacological preventive strategies exist, 4 they are often inconsistently prescribed and inadequately administered. 5–7 It is unclear why patients fail to receive adequate prophylaxis in the hospital. Medication adherence to regimens with proven efficacy in clinical trials results in beneficial outcomes in routine practice. 8 We have previously used our hospital’s computer system to identify patients at high risk for venous thromboembo- lism who were not receiving prophylactic measures and to alert their providers about the need for prophylaxis. 9 This strategy resulted in a 41% reduction in symptomatic venous Funding: Sanofi-aventis. Conflict of Interest: John Fanikos, RPh, MBA serves on the Speakers Bureau for sanofi-aventis and GlaxoSmithKline and has served as a consultant/ advisory board participant. Samuel Z. Goldhaber, MD, receives research funds and is a consultant for sanofi-aventis, Eisai, Bristol-Myers Squibb, and Boehr- inger-Ingelheim. The remaining authors have no conflicts to disclose. Authorship: All authors had access to the data and participated in the manuscript preparation. Requests for reprints should be addressed to Samuel Z. Goldhaber, MD, Cardiovascular Division, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA 02115. E-mail address: sgoldhaber@partners.org 0002-9343/$ -see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.amjmed.2009.11.017