National trends in deep vein thrombosis (DVT) hospitalizations: Comparing in-hospital outcomes in patients with versus without lymphoma (2016-2022)

Abstract Introduction: Deep vein thrombosis (DVT) is a potentially life-threatening complication in patients with cancer. Among cancers, lymphomas have a particularly elevated risk of thromboembolism due to both disease-related factors and chemotherapy. Although the association between lymphoma and thrombosis is established, the impact of lymphoma on inpatient outcomes among patients with DVT remains deficient, especially at a national level. Using seven years of data from the National Inpatient Sample (NIS), the largest all-payer inpatient database in the United States, this study aims to examine epidemiology, clinical outcomes, healthcare costs, and characterize the burden for hospitalized DVT patients with and without a diagnosis of lymphoma. Methods: Hospitalizations for DVT and Lymphoma were identified using ICD-10-CM codes from the NIS for years 2016-2022, and integrated sampling weights were applied to generate nationally representative estimates. The primary outcomes analyzed using logistic and linear regression were in-hospital mortality, average length of stay (LOS), and total hospital charges, while secondary outcomes included in-hospital complications. Outcomes were adjusted for demographics and comorbidities. Results were reported as adjusted odds ratios (aOR), and a p<0.05 was considered statistically significant. Statistical analysis was performed by the STATA (version 17). Results: In our sample of 2,929,708 hospitalizations for deep vein thrombosis (DVT) from 2016 to 2022, 52,035 (1.8%) involved patients who also carried a diagnosis of lymphoma. Compared with patients without lymphoma, this subgroup was older on average (mean age 65.4 vs. 64.5 years, p<0.0001), more often male (57.9% vs. 51.8%, p<0.0001), and more frequently White (72.2% vs. 67.6%), with fewer Black patients (10.9% vs. 18.8%, p<0.0001). The Charlson Comorbidity Index (CCI) suggested significant comorbidity burden in lymphoma subgroup (45.9% vs. 32.4% with a CCI ≥ 4). However, individual comorbidities were less frequent in the lymphoma group: diabetes (22.2% vs. 28.4%), chronic kidney disease (15.6% vs. 18.4%), and obesity (12.6% vs. 20.8%), all with p<0.0001. Patients with lymphoma had higher likelihood of developing sepsis (21.4% vs. 18.0%, p<0.0001), disseminated intravascular coagulation (1.3% vs. 0.8%, p<0.0001), and acute kidney injury (31.1% vs. 29.3%, p=0.0002). Pulmonary embolism was less common in the lymphoma group (18.8% vs. 31.1%, p<0.0001). Bleeding events and adverse effects of anticoagulants were less frequent in lymphoma patients. In-hospital mortality was significantly higher in the lymphoma group (10.0% vs. 6.8%), with an aOR of 1.21 (95% CI: 1.13–1.30, p<0.0001). Furthermore, mean LOS was longer in the lymphoma subgroup (11.8 vs. 10.0 days). Adjusted analysis demonstrated an additional 1.16 days in lymphoma patients (95% CI: 0.84–1.48, p<0.0001). Lastly, Hospitalization costs were also higher in the lymphoma group (mean $171,602 vs. $139,171), which rose to $19,804 higher charges after adjustment (95% CI: $12,206–$27,403, p<0.0001). Conclusions: Over seven years of NIS data, we identified nearly 3,000,000 DVT admissions, 1.8% of which involved lymphoma. Classic comorbidities such as diabetes and CKD were both less common in these patients, yet they faced a 21% higher chance of dying in the hospital, stayed about two days longer, and incurred nearly $20,000 more in charges. They were also less prone to pulmonary embolism but far more likely to develop sepsis, DIC, and acute kidney injury. This pattern reveals a heavy inpatient burden for DVT in lymphoma and underscores the need to discover the underlying mechanisms behind these gaps, and to translate that knowledge into personalized care plans.