OBJECTIVES: This study explores the disparity in clinical outcome in multiple myeloma patients by different demographic variables.

METHODS: This study included patients with multiple myeloma between Jan 1, 2017 to Dec 31, 2019, with relevant ICD-9 and ICD-10-CM diagnosis recorded in the Optum® de-identified Market Clarity Dataset, which links medical and pharmacy claims with EHR data from providers across the continuum of care. Patients with continuous eligibility/healthcare activity of pre- and post-index 12 months were included in the study. We have looked for patients with lab results in both baseline (+/- 90 days from the index date) and 12-month follow-up time-period (+/- 90 days to index+12 months) for the specific test of Kappa chain and Free Light Chain (FLC) ratio (Kappa/Lambda ratio). Patients who had lab results in both baseline and follow-up time-period were considered. Lab record closest to the index date was considered for the estimation. We excluded the lab records with zero or any text values in the lab result column and looked for the next available lab record in the observation window. The difference/change in lab results from baseline to follow-up was statistically tested by the Wilcoxon Signed-rank sum test.

RESULTS: 1,593 and 1,326 patients met the study method criteria for Kappa chain assessment and FLC assessment, respectively. Whites, Black, and Hispanics had median baseline Kappa chain levels of 28.9, 32.7, and 49.1 mg/L, respectively. Likewise, Whites, Blacks, and Hispanics had median baseline FLC ratios of 1.6, 1.8, and 2.4, respectively. Moreover, only Whites had a statistically significant change in Kappa level (p<0.0001) and FLC level (p<0.0001) after a 12-month follow-up.

CONCLUSIONS: Blacks and Hispanics were found to present their multiple myeloma condition with more severity at baseline. Furthermore, Blacks, Hispanics, and Asians showed no significant difference in clinical outcomes after 12- months of diagnosis.