Chemotherapy Refusal Patterns in Multiple Myeloma Patients: An in-Depth Analysis of the NCDB Data from 2004 to 2020

Background: Chemotherapy is a cornerstone in the treatment of multiple myeloma (MM), contributing to prolonged patient survival. However, despite its proven efficacy, some individuals opt to decline chemotherapy, leading to variations in treatment strategies and outcomes. Understanding the factors associated with the decision to decline chemotherapy in MM patients is crucial for optimizing patient-centered care and ensuring equitable access to appropriate treatments. Our investigation aims to illuminate potential areas for targeted interventions, with the goal of enhancing patient engagement and optimizing treatment strategies to improve overall outcomes in MM management.

Methods: N=152,299 patients diagnosed with MM between 2004 and 2020 were identified using the NCDB, all of whom were recommended for chemotherapy. Overall survival (OS) of patients who received chemotherapy compared to those who did not receive it was evaluated and presented using Kaplan-Meier (KM) curves. Multivariate logistic regression analysis with backward elimination was used to identify factors associated with refusal of chemotherapy. SAS version 9.4 was used to analyze the data.

Results: Among 152,299 patients who received a recommendation for chemotherapy from their physicians, 3,289 individuals (2.16%) opted to refuse the treatment. Descriptive statistics for patients who refused chemotherapy are presented in Table 1. The median OS for patients who received chemotherapy was 61.37 months, in contrast to 8.8 months for those who declined this treatment (Figure 1). Our multivariate logistic regression analysis revealed several significant factors associated with chemotherapy refusal in MM patients. Age exhibited a statistically significant association, with increasing odds of refusal observed in patients aged 60-69 years (OR=1.29, p=0.045), 70-79 years (OR=2.26, p<0.0001), and 80 years and older (OR=7.29, p<0.0001) compared to those younger than 50 years. Male patients exhibited lower odds for refusal (OR=0.85, p<0.0001) compared to female patients. Black patients had higher odds for refusal (OR=1.26, p<0.0001) compared to White patients. Patients with Medicare, Medicaid/other government insurance, and no insurance had higher likelihood of refusal (OR=1.71, 1.89 and 3.13 respectively, p<0.0001) than patients with private insurance. The Charlson-Deyo score demonstrated a significant association, with higher scores correlating with increased odds of refusal (p<0.0001). Patients treated at non-academic facilities had higher odds of refusal (OR=1.47, p<0.0001) compared to academic facilities. Education was significantly associated with refusal, with patients having lower education levels exhibiting increased odds of refusal. Patients living in areas where more than 21% of the area residents have no high school diploma (HSD) had higher odds of chemotherapy refusal compared to patients living in areas where less than 7% have no HSD (OR=1.28, p=0.0026). The year of diagnosis was also linked to refusal, with patients diagnosed between 2004-2007, 2008-2011, and 2012-2015 having higher odds of refusal compared to those diagnosed between 2016-2020 (OR=1.62, 1.25 and 1.27 respectively, p<0.0001). It is also important to note that geographical location played a role, with patients treated in the East North Central, Mountain, and Pacific regions exhibiting significantly higher odds for refusal compared to the South Atlantic region (OR=1.17, 1.35 and 1.16 respectively, p=0.01, 0.002 and 0.03 respectively).

Conclusion: Our comprehensive analysis of MM patients shows that the chemotherapy refusal rate in the real-world setting is low at 2.16%. Despite the low rate of refusal, this study did identify several important factors significantly associated with chemotherapy refusal in this patient population. Older age, female sex, Black race, non-private insurance, higher comorbidities, lower education level, non-academic facility type, earlier year of diagnosis, and East North Central, Mountain, and Pacific facility locations were associated with higher likelihood of declining chemotherapy. Our findings emphasize the importance of considering socioeconomic (level of education, insurance status), as well as racial and regional factors, while developing targeted interventions to address disparities in order to enhance engagement in myeloma care.