Prevalence and Trends of in-Hospital Outcomes Among Patients with Multiple Myeloma and Monoclonal Gammopathy of Undetermined Significance: National Inpatient Sample 2016-2020
Authors: Jayakumar Jayalekshmi , Sinha Samridhi , Gaddam Mrunanjali , Iqbal Rabia , Kavuri Swathi , Colon Ramos Ana , Singh Surbhi , Atluri Sobha , Koifman Michelle , Quadri Kalimullah 
Published: December 2024

Background:
Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition which precedes Multiple Myeloma (MM). MM is an incurable malignancy of plasma cells, characterized by remissions and relapses. Patients with MM and MGUS are at an increased risk of developing deep vein thrombosis (DVT) due to circulating paraproteins and sepsis, impaired immune system and frequent hospitalizations. Additionally, MM patients can develop acute kidney injury(AKI), frailty secondary to to bone involvement and tumor lysis syndrome (TLS). In this study, we analyzed the trends of in-hospital outcomes of patients with MM and MGUS with focus on those admitted for DVT.
Methods:
The National Inpatient Sample database (2016 to 2020) was used to identify MM or MGUS hospitalizations, using International Classification of Diseases-10th Revision codes. This dataset was utilized to analyze trends of in-hospital outcomes for patients with MM and MGUS. Additionally, we focused on analyzing the prevalence and trends of in-hospital outcomes for MM and MGUS patients admitted with DVT, along with the sociodemographic factors influencing the same.
Results:
A total of 819,614 MM hospitalizations were identified. Mean age was 69.43 years, of which 43.91% were females. There were 63.65% Whites, 22.21% Blacks, and 8.46% Hispanics (p &lt; 0.001). MM patients showed a statistically significant upward trend in the prevalence of in-hospital complications, including sepsis (11.33% in 2016, 12.24% in 2017, 12.71% in 2018, 12.57% in 2019, and 11.76% in 2020) [p = 0.001]; AKI (31.95% in 2016, 32.44% in 2017, 33.08% in 2018, 33.49% in 2019, and 36.46% in 2020) [p &lt; 0.001]; frailty (0.17% in 2016, 0.23% in 2017, 0.25% in 2018, 0.44% in 2019, and 0.46% in 2020) [p &lt; 0.001]; and TLS (0.63% in 2016, 0.67% in 2017, 0.76% in 2018, 0.86% in 2019, and 0.95% in 2020) [p = 0.002]. The trends for disseminated intravascular coagulation (DIC) and bleeding in MM patients were not statistically significant. The prevalence of DVT among MM patients was 0.86%. A significant increase in trends among MM hospitalizations with DVT was found (4.16% in 2016, 4.16% in 2017, 4.36% in 2018, 4.59% in 2019, and 4.51% in 2020) [p = 0.012]. Among MM patients with DVT, trends in mortality (6.97% in 2017, 5.24% in 2017, 7.4% in 2018, 7.3% in 2019, and 7.27% in 2020) [p = 0.05] were significant. No significant differences in trends were found for leg ulcers, chronic venous insufficiency, post-thrombotic syndrome(PTS), and acute pulmonary embolism(PE) among MM patients with DVT. The mean length of stay (LOS) and total charges (TOTCHG) among MM patients with DVT were 10.76 days and $115,496, compared to 6.54 days and $70,272 for those without DVT, respectively.
We identified 329,699 MGUS hospitalizations. The mean age of MGUS patients was 73.86 years, and 46% were females. 68.91% were Black, 20.6% were White, and 5.73% were Hispanic (p &lt; 0.001). MGUS patients showed a significant increase in trends for sepsis (9.4% in 2016, 10.77% in 2017, 10.36% in 2018, 9.98% in 2019, and 9.45% in 2020) [p = 0.006]; AKI (32.54% in 2016, 34.94% in 2017, 34.6% in 2018, 35.02% in 2019, and 37.78% in 2020) [p &lt; 0.001]; frailty (0.31% in 2016, 0.29% in 2017, 0.37% in 2018, 0.61% in 2019, and 0.80% in 2020) [p &lt; 0.001]; and DIC (0.24% in 2016, 0.4% in 2017, 0.31% in 2018, 0.19% in 2019, and 0.27% in 2020) [p = 0.05]. The trends for TLS and bleeding in MGUS patients were not statistically significant. In MGUS, the prevalence of DVT was 0.71%, which remained stable over the years (3.79% in 2016, 3.25% in 2017, 3.68% in 2018, 3.86% in 2019, and 3.47% in 2020) [p = 0.04]. Among MGUS patients with DVT, in-hospital mortality was on an upward trajectory (4.98% in 2016, 4.5% in 2017, 5.29% in 2018, 5.5% in 2019, and 7.76% in 2020), but this was not statistically significant [p = 0.45]. Chronic venous insufficiency trends among MGUS patients with DVT also showed a significant increase (1.55% in 2016, 3.54% in 2017, 3.9% in 2018, 2.5% in 2019, and 3.58% in 2020) [p = 0.015]. However, trends for leg ulcers, PE and PTS were not significant. Mean LOS and TOTCHG among MGUS patients with DVT were 10.69 days and $129,631, compared to 7.01 days and $80,303 for MGUS patients without DVT, respectively.
Conclusion:
Significant variability exists in the trends of in-hospital outcomes of MM and MGUS. Understanding these disparities can help optimize management of these patients, to improve their overall healthcare quality and outcomes.