Ethnic Disparities in AL Amyloidosis Outcomes Among Hospitalized Patients in the United States

INTRODUCTION

Health disparities in immunoglobulin light chain (AL) amyloidosis have not been well described. We aimed to assess if health disparities between non-Hispanic (NH)-Whites, NH-Blacks and Hispanics exist and to describe differences between different ethnic/racial groups.

METHODS

We conducted a retrospective cross-sectional analysis of in-patient AL amyloidosis hospitalizations from 2016 to 2018 using the Nationwide Inpatient Sample (NIS), a database which provides nationally representative information on hospitalizations in the U.S. The studied period was chosen to capture data from the ICD-10-CM codes to avoid misclassification of AL amyloidosis which was grouped with other cases of ATTR amyloidosis in the ICD-9-CM coding system. All hospitalizations in adults (age ≥18 years) were included. The exposure for the study was the occurrence of AL amyloidosis in the discharge records. Outcomes were [1] in-hospital death [2] chemotherapy use; [3] intensive care unit (ICU) utilization; [4] palliative care consultation. The analysis for this study was performed using R program version 3.5.1; a 5% type I error rate for all hypothesis tests (two-sided) was assumed.

RESULTS

Admissions related to AL amyloidosis constituted 0.03% of all hospitalizations in the study period (25,470 of 90,869,381). The prevalence of AL amyloidosis related hospitalizations was higher in NH-Blacks when compared with NH-Whites (42.8 vs.28.1 per 100,000 hospitalizations). AL amyloidosis related in-hospital mortality rate was higher in NH-Whites and Hispanics when compared to NH-Blacks (6.6%% and 6.2% vs. 4.9%). In-hospital mortality with AL amyloidosis was higher in older patients, males and those who self-paid for their treatment. Utilization of ICU care was more common in NH-Blacks when compared to NH-Whites (6% vs. 4.8%). Hispanics had the lowest inpatient chemotherapy use (1.7% vs. 2.9%). Multivariable adjusted association between race/ethnicity and various outcomes showed a trend towards lower in-hospital mortality in NH-Blacks when compared to NH-Whites (OR: 0.76, 95% CI: 0.55-1.05, p=0.09) and lower utilization of palliative care services in NH-Blacks when compared with NH-Whites (OR: 0.61, 95% CI: 0.42-0.88, p=0.01). Despite very low numbers of transplant related admissions, such admissions occurred only in NH-Whites.

CONCLUSIONS

Our findings highlight disparities in AL amyloidosis care for NH-Blacks and Hispanics. NH-Blacks tend to have lower in-hospital mortality with higher utilization of ICU care, nevertheless, they receive the lowest palliative care services. Despite the higher utilization of ICU care, data suggest possible superior outcomes of AL amyloidosis in NH-Blacks when compared to NH-Whites.