Venous Thromboembolism Prophylaxis

This recommendation was upgraded from Moderate to Strong due to the large potential benefit and relatively low risk of implementation. 

Six moderate quality studies (Eskeland 1966; Jorgensen1992; Jorgensen 1998; Morris 1976; PEP Study 2000; Sasaki 2009) and four low quality studies (Chang Y H 2019; Goh E L 2020; Kulachote N 2015, Zhang C 2018) were identified comparing various pharmacological prophylaxis interventions in the setting of hip fracture. One moderate strength study (Stranks 1992) compared mechanical prophylaxis to a group that received no mechanical prophylaxis.  These studies were an update of those utilized in the 2014 CPG guideline on the same topic, and excluded some previous studies judged to not meet current criteria for inclusion.  Of these included studies, evidence shows the risk of DVT/VTE/PE complication is significantly less with VTE prophylaxis than control. Most general complications were not significantly different between treatment groups and there is some evidence that mortality is less with prophylaxis. 

Given the significant established risk factors for VTE present in this patient population including age, presence of hip fracture, major surgery, delays to surgery, and the potential serious consequences of failure to provide prophylaxis in the hip fracture population, it is the recommendation of the workgroup that VTE prophylaxis be used.  

With regard to mechanical prophylaxis, in the absence of a contraindication, this mechanical intervention can be applied with good efficacy for decreasing VTE, reasonable cost, and little risk to patient safety.

With regard to chemical prophylaxis, moderate quality evidence suggests that this may decrease patient risk of VTE/PE, with minimal risk of increased hemorrhagic consequences.  There is however insufficient evidence to recommend a specific pharmacologic agent or duration of treatment.   Patient specific factors should be considered when choosing an anticoagulated agent such as patient immobility, comorbidities, or bleeding risks. 

Benefits/Harms of Implementation

Patients with hip fracture are at high risk for deep venous thrombosis and pulmonary embolism. The consequences of symptomatic VTE are significant and include both increased morbidity and mortality. The harms associated with this recommendation include those associated with over or under treatment in the prevention of VTE/PE.  Potential patient risks include thrombotic event, patient burden for administration route as well as risk of over treatment including hemorrhagic event. Given the potentially dire consequences of a VTE, and the relatively low risk of VTE prophylaxis, the committee voted to upgrade this to a strong recommendation despite the moderate evidence. 

Cost Effectiveness/Resource Utilization

Mechanical prophylaxis is available at most medical institutions in the United States and is typically an available adjunct without major cost or need for additional resources.  Aspirin may be a cost-effective agent for appropriately selected patients and is able to be administered in an oral route, with little education, and low cost.  Low Molecular Weight Heparin may also prove cost effective for appropriate patients, however, requires education on administration and patient compliance.  This chemoprophylactic agent has no typical monitoring costs.  Coumadin is a cost-effective means of anticoagulation for appropriately selected patients and is able to be administered in an oral route.  This however requires post discharge monitoring which may require system resources and additional patient education.  NOAC/DOAC medication are an effective but more costly means of VTE prophylaxis for appropriately selected patients and are able to be administered in an oral route, with little education and no post discharge monitoring. 

Future Research

The issue of VTE prophylaxis in patients who have sustained a hip fracture is complex. There are many unanswered questions that have the potential to have a significant impact on clinical outcomes for this patient population. A multi-armed randomized controlled study would be optimal. Such a study would potentially need to evaluate the comparative effectiveness of a multitude of chemical agents, at different dosages, with multiple time points (such as pre- and post-op), and include assorted durations of therapy, while utilizing contemporary diagnostic methodologies. Barriers to such a study include the low incidence of the complication implicating a requirement for a substantially large sample size. Furthermore, such a study carries ethical concerns given the potential risks associated with under-treatment. Potentially, well organized patient outcome registries may ultimately help improve our knowledge in this area and advances in large data-set machine learning algorithms may also help sort through the complexity of these mixed patient groups and their treatment needs.