Venous thromboembolism in multiple myeloma: A nationwide analysis of risk factors, mortality, and disparities

Abstract Background Venous thromboembolism (VTE) contributes substantially to morbidity and mortality in individuals with multiple myeloma. However, real-world data characterizing the burden of VTE, its association with inpatient mortality, and the influence of demographic and socioeconomic variables remain limited. Methods We conducted a retrospective cohort study using the National Inpatient Sample (NIS) database. Adult hospitalizations with a diagnosis of multiple myeloma (MM) from 2020 to 2022 were identified using ICD-10-CM codes. VTE events, including deep vein thrombosis and pulmonary embolism, were also identified using ICD-10-CM codes. The outcomes assessed include inpatient mortality, VTE incidence and its association with demographic characteristics (age, sex, race/ethnicity), socioeconomic factors (zipcode–based income quartile, insurance status), and hospital characteristics. Descriptive statistics, chi-square tests, and logistic regression were used to compare outcomes of multiple myeloma patients with vs without VTE. Results A total of 68,488 hospitalizations with multiple myeloma were included, of which 3,405 (4.97%) were associated with VTE as one of the admission diagnoses. Hospitalizations with VTE among MM patients had significantly higher odds of inpatient mortality compared to those without VTE (adjusted odds ratio [aOR] 1.78, 95% CI 1.58–2.02; p < 0.001). In multivariable logistic regression adjusting for age, sex, race, obesity, and secondary malignancies, mean age did not differ significantly between hospitalizations with and without VTE (70.08 vs. 70.13 years; p = 0.74). Black patients with MM had higher odds of hospitalization associated with VTE compared to White patients (OR 1.35, 95% CI 1.24–1.46; p < 0.001), while those involving Asian or Pacific Islander individuals had lower odds (OR 0.68, 95% CI 0.52–0.90; p = 0.007). No significant differences were observed for subgroup listed as other races. Hospitalizations involving female individuals showed a trend towards increase in VTE odds (aOR 1.07, 95% CI 1.00–1.15; p = 0.066). Obesity (OR 1.15, 95% CI 1.04–1.26; p = 0.005) and secondary malignancies (OR 1.44, 95% CI 1.31–1.59; p < 0.001) were significantly associated with higher VTE odds. In univariate models, there were no significant differences in VTE incidence by insurance type (p = 0.25), income quartile (p = 0.64), or urban-rural hospital location (p = 0.012), although geographic variation was minimal. Discussion In this analysis of a national inpatient multiple myeloma database, VTE was associated with a 78% increase in the odds of inpatient mortality. Odds of VTE were higher among hospitalizations involving Black patients and lower among those involving Asian or Pacific Islander individuals. While risk models such as the IMPEDE score account for Asian race as a protective factor, Black race is not currently included. Further studies are needed to validate these findings in both inpatient and outpatient settings. The lack of significant differences by insurance status, income quartile, or hospital location suggests that racial and clinical factors such as obesity and the presence of a secondary malignancy may have a greater influence on the odds of VTE than socioeconomic status. These findings underscore the value of real-world data in refining risk stratification and support targeted inpatient VTE prevention strategies.