Comparison of the effectiveness of venous thromboembolism prophylaxis with enoxaparin between obese and non-obese patients

Objective The purpose of this study is to compare the incidence of venous thromboembolism between obese and non-obese hospitalized patients who received United States Food and Drug Administration-approved prophylactic enoxaparin doses and to describe enoxaparin dosing strategies used in obese patients. Methods This was a retrospective cohort study including patients who were admitted to Parkview Regional Medical Center, Parkview Hospital, or Parkview Orthopedic Hospital between September 2011 and August 2012 and received at least one dose of enoxaparin 30 mg twice daily or enoxaparin 40 mg once daily for venous thromboembolism prophylaxis. Patients classified based on their body mass index into three groups, Group 1 (non-obese: body mass index < 25 kg/m(2)), Group 2 (overweight: body mass index >= 25 kg/m(2) but < 30 kg/m(2)), and Group 3 (obese: body mass index >= 30 kg/m(2)). The primary endpoint was venous thromboembolism occurrence within 90 days, considering day 1 of hospitalization as day 1. Results Of the 428 patients included, 8 cases of venous thromboembolism (1.9%) were identified; 3 in the non-obese group, 2 in the overweight group, and 3 in the obese group, no statistically significant differences were found between the three groups, p = 0.81. When venous thromboembolism incidence was adjusted for age and sex, no statistically significant differences were found between overweight (OR = 0.685; 95% CI 0.115-4.095), obese (OR = 0.797; 95% CI 0.353-1.796), and combined overweight and obese (OR = 0.656; 95% CI 0.154-2.799) groups compared to patients with normal body weight. Conclusion This study did not find a statistically significant difference in venous thromboembolism incidence between obese, overweight, and non-obese hospitalized patients receiving approved enoxaparin prophylaxis doses.