Introduction
Venous thromboembolism (VTE) in children, adolescents, and young adults (AYAs) typically develops in the setting of multiple thrombotic risk factors, including central venous access, severe illness/inflammation, surgery, and/or high estrogen state. While rare in healthy children, VTE occurs in up to 58 cases per 10,000 pediatric hospital admissions.1-6 Although the risk factors, associated medical conditions, and sites of thrombosis vary across children and AYAs, therapeutic anticoagulant medications (i.e., oral vitamin K antagonists, subcutaneously injected low molecular weight heparin, newer direct oral anticoagulants) are prescribed to promote thrombus resolution while preventing thrombus extension, embolization, or formation at new sites.7 Anticoagulant adherence is presumed to be critical for maximizing health outcomes, yet emerging literature shows that 2-42% of children and AYAs demonstrate non-adherence or medication-taking that differs from the prescribed treatment regimen.8-10
To date, pediatric and AYA VTE research has found that younger age and lower parental education are associated with lower adherence,8.9 but the modifiable factors, or barriers, that may lead to non-adherence have not yet been examined. A critical next step for the field and the primary aim of this project was to begin to identify barriers to anticoagulation adherence among children and AYAs. The secondary aim was to explore the relationship between barriers and adherence. If, as hypothesized, a higher number of barriers is associated with lower adherence, these data would provide support for developing adherence-promotion interventions targeting barriers. Adherence-promotion interventions in children and AYAs prescribed anticoagulants thus far have targeted general education and the promotion of self-efficacy, and produced minimal improvements in adherence rates.11-13 Understanding barriers that could be targeted to improve anticoagulation adherence, thus, is an essential step in improving outcomes for children and AYAs prescribed anticoagulants.