Predictors of 90-Day All-Cause Readmissions in Multiple Myeloma: Insights From the National Readmissions Database
Introduction/Background/Significance: Multiple myeloma carries a high disease burden, with only a 62% survival rate at the five-year mark. However, little is known about the factors that contribute to increased readmissions in these patients. This study aims to identify hospital-specific and comorbidity-related variables associated with readmission and to quantify the overall healthcare burden of such events
Materials and Methods/Case Presentation/Objective: We conducted a retrospective study using the 2022 Nationwide Readmissions Database (NRD), part of the Healthcare Cost and Utilization Project. Patients hospitalized with a diagnosis of multiple myeloma between January and October were selected as the study population. The first readmission within 90 days of the initial (index) hospitalization was used to define the readmission cohort. Using survey-weighted logistic, linear, and Cox regression models, we examined clinical and hospital-level characteristics and identified predictors of 90-day readmission
Results/Description/Main Outcome Measures: A total of 54,720.76 admissions were identified as index; among these, 14,972.43 were readmitted within 90 days of their index admission. Among index admissions, 2,768.25 patients died. The mean length of stay for index admissions was 8.51 days, with mean total charges of $124,045 and mean total cost of $30,668.46. Among readmitted patients, the mean total cost was $30,201.54, mean total charges were $123,262.20, and mean length of stay was 8.62 days. The cumulative length of stay for all readmissions combined was 129,112.1 days, with cumulative total cost at $448 million and cumulative total charges at $1.83 billion. The most common primary diagnosis among readmitted patients was sepsis (weighted total: 2,264). Other frequent diagnoses included acute kidney injury (771), hypertensive heart and chronic kidney disease with heart failure (815), COVID-19 (489), pneumonia (361), hypertensive heart disease with heart failure (283), neutropenia (208), urinary tract infection (198), and hypertensive heart and chronic kidney disease with ESRD (198). Increasing age was associated with a slightly decreased hazard of 90-day readmission (aHR 0.996, p=0.005). Compared to the lowest income quartile, patients in the third quartile had a reduced hazard of readmission (aHR 0.91, p=0.010). Patients admitted to urban non-teaching hospitals had a lower hazard of readmission (aHR 0.88, p=0.045). A higher Charlson comorbidity index (≥3) was significantly associated with increased readmission risk (aHR 1.30, p< 0.001). Insurance status was also associated with readmission: compared to private insurance, Medicaid (aHR 0.89, p=0.011), other government insurance (aHR 0.74, p=0.016), and self-pay/uninsured (aHR 0.84, p=0.041) were all linked with reduced hazard. Among clinical factors, venous thromboembolism (aHR 1.12, p=0.022), hypercalcemia (aHR 1.22, p< 0.001), anemia (aHR 1.21, p< 0.001), type 2 diabetes mellitus (aHR 1.08, p=0.009), amyloidosis (aHR 1.19, p=0.003), and tumor lysis syndrome (aHR 1.49, p=0.001) were independently associated with increased readmission hazard
Conclusions: Several variables influenced readmissions in multiple myeloma, the most common being infections, kidney issues, or side effects from treatment. Who gets readmitted also seems to depend on where they were treated, what kind of insurance they had, and their overall health. Understanding these trends can help us provide better care and improve outcomes
