An analysis of in-hospital enoxaparin prescription and bleeding in the predominately middle-, and oldest-old population: insights from a secondary care hospital

Abstract

Background: Enoxaparin is one of the widely used injectable anticoagulants requiring dose adjustment based on body weight and renal function. Unadjusted or inappropriately adjusted doses can lead to thromboembolic or bleeding events, particularly in patients with advanced age. Objectives: This retrospective chart review study primarily aimed to evaluate enoxaparin use, along with exploring factors associated with inappropriate use and bleeding in the elderly population. Methods: Baseline characteristics, along with bleeding and thrombotic events, of the patients receiving enoxaparin in the fiscal year 2018-2019 at a secondary care hospital were extracted from the electronic medical record. Prescribed enoxaparin regimens were evaluated against the recommended dose in the package insert, pertinent guidelines, and hospital guidance. Univariate and multivariate analyses were performed to explore factors associated with inappropriate use and bleeding. Results: Two hundred and fourteen patients were included. The majority (66.8%) were female, and 39.7% were 80 years or older, with an average age of 74.4 years and a body mass index (BMI) of 24.0 kg/m2. Most patients (82.7%) had a creatinine clearance ≥30 ml/min. Seventy-six initiations (35.5%) were inappropriate, and 83 problems were found. Underdosing was the most common problem (39.8%), followed by undocumented body weight (22.9%), and inconsistent prophylactic dose per hospital guidance (20.5%). BMI ≥25kg/m2 (odds ratio [OR] 2.04 [95% confidence interval [CI] 1.04:3.98]; p=0.04) was the only factor associated with inappropriate use. There were 48 bleedings (22.4%), 21 minor (9.8%), and 27 major (12.6%). Hemoglobin (Hb) <10g/dL was associated with bleedings across all indications (OR 4.25 [95%CI 2.03:8.91]; p<0.01). Conclusions: In the predominately middle-, and oldest-old population, inappropriate use of enoxaparin was common. Those with BMI ≥25kg/m2 and Hb<10g/dL were at increased risk of underdosing and bleedings, respectively; these patients should be closely monitored.