Incidence of Venous Thromboembolism in a Homebound Population: A Retrospective Cohort Study

Background:

Venous thromboembolism (VTE) is a source of morbidity and mortality for high‐risk populations. The risk of VTE in homebound patients is unknown, and therefore it is unclear whether they should be offered VTE prophylaxis when feasible. The purpose of this retrospective cohort study was to estimate the incidence of venous thromboem‐bolism (VTE) in homebound patients.

Methods:

The study sample included all patients active in a home‐based primary care program, the Mount Sinai Visiting Doctors Program; VDP), over a 4‐year period. Outpatient medical records and relevant inpatient admissions or clinical testing were retrospectively reviewed. Data were extracted to determine whether the patient experienced a VTE and if the event occurred in a home setting while the patient was enrolled in the VDP. Baseline functional assessment scores were abstracted when available. Incident VTE in a home setting was defined as the diagnosis of a symptomatic deep vein thrombosis or pulmonary embolism that did not occur during a hospitalization, within 4 weeks of a medical hospitalization, or within 12 weeks of a surgical hospitalization. Definite VTE was defined as events substantiated by clinical testing (Doppler ultrasound, CT angiography, ventilation–perfusion scan, and/or pulmonary angiography.) Probable VTE was defined as events not substantiated by clinical testing but that resulted in a decision to anticoagulate. Incident VTE was calculated as the number of patients with probable and or definite VTE over person time. Statistical analysis was done using the Student t test.

Results:

A total of 1913 patients were enrolled in the VDP during the study period. The database queries yielded 196 patients with possible home‐based VTE for full chart review. From these patients, there were 33 VTE events (28 definite and 5 probable) that occurred in a home setting, yielding an incidence rate of 0.68 symptomatic VTE events per 100 person years (95% CI, 0.448–0.912). There was no difference in baseline functional assessment scores for patients with or without incident VTE.

Conclusions:

The estimated incidence of VTE in a chronically homebound population is low and does not correlate with baseline functional status. There is insufficient evidence to recommend VTE prophylaxis for this patient population.

Disclosures:

J. Ahmed ‐ none; K. Ornstein, none; A. Dunn ‐ none; P. Gliatto ‐ none