Abstract
Venous thromboembolism (VTE) is a relatively common complication among patients undergoing
primary total knee arthroplasty (TKA). This complication occurs in a spectrum of severity
ranging from an incidental finding to serious readmission-requiring events. To date,
the risk factors of serious VTE that require readmission have not been characterized.
This study examines the patient and hospital characteristics associated with readmission
for serious VTE after TKA. The National Readmission Database (NRD) from the Agency
of Healthcare Research and Quality (AHRQ) was queried for patients who underwent primary
TKA from January 2016-December 2018. The study population consisted of patients who
were readmitted within 90 days following primary TKA with a primary diagnosis of VTE.
Multivariable regression models were constructed to evaluate patient characteristics
(age, sex, insurance, elective nature of procedure, hospital characteristics, discharge
status, income, and comorbidities) associated with higher risk of developing readmission-requiring
VTE. Readmission rates for VTE exhibited a higher incidence in patients older than
61 (compared with 40 and under), males (OR:1.08, 95%CI [1.03–1.14]), patients with
nonelective procedures (OR:20.21, 95% CI [19.16–21.32]), patients at large hospitals(OR:1.17,
95% CI [1.09–1.25]), patients at private hospitals (OR:1.19, 95% CI [1.09–1.29]),
and patients with non-home discharge statuses. Comorbidities of paralysis (OR:1.52,
95% CI [1.19–1.94]), neurological disorders (OR:1.12, 95% CI [1.02–1.23]), metastatic
cancer (OR:1.48, 95% CI [1.01–2.17]), obesity (OR:1.11, 95% CI [1.06–1.17]), fluid
and electrolyte imbalance (OR:1.28, 95% CI [1.18–1.38]), blood loss anemia (OR:1.29,
95% CI [1.02–1.64]), and iron deficiency anemia (OR:1.24, 95 % CI [1.15–1.33]) increased
risk of VTE. Certain comorbidities requiring chronic anticoagulation were associated
with lower risk of VTE. Insurance status and patient income did not exhibit any correlation
with VTE incidence. Patient characteristics of male sex, age > 61, and baseline comorbidities
(paralysis, neurological disorders, metastatic cancer, obesity, fluid and electrolyte
imbalance, and blood loss/iron deficiency anemia) were at an increased risk of developing
serious VTE. Patients without continued supervision at their discharge environment
were at higher risk of developing serious VTE. Extra prophylaxis and special protocols
may be warranted in these patients to prevent VTE complications.
Keywords
venous thromboembolism - total knee arthroplasty - readmission - risk factors - comorbidities
- discharge status
