Racial Differences In Clinical Outcomes Research Articles

Infectious Inequity: How the Gut Microbiome and Social Determinants of Health May Contribute to Clostridioides difficile Infection Among Racial and Ethnic Minorities.

Infectious diseases are a leading contributor to death in the United States, and racial differences in clinical outcomes have been increasingly reported. Clostridioides difficile infection (CDI) is a growing public health concern, as it causes nearly half a million infections per year and considerable excess hospital costs. Concurrent with other infectious diseases, recent literature denotes racial disparities in CDI incidence rates, mortality, and associated morbidity. Of note, investigations into CDI and causative factors suggest that inequities in health-related social needs and other social determinants of health (SDoH) may cause disruption to the gut microbiome, thereby contributing to the observed deleterious outcomes in racially and ethnically minoritized individuals. Despite these discoveries, there is limited literature that provides context for the recognized racial disparities in CDI, particularly the influence of structural and systemic barriers. Here, we synthesize the available literature describing racial inequities in CDI outcomes and discuss the interrelationship of SDoH on microbiome dysregulation. Finally, we provide actionable considerations for infectious diseases professionals to aid in narrowing CDI equity gaps.

Lack of racial differences in clinical outcomes of breast cancer patients receiving neoadjuvant chemotherapy: a single academic center study.

To examine the association between race and clinical outcomes (pathological complete response [pCR]; recurrence-free survival [RFS], and overall survival [OS]) in patients diagnosed with triple-negative (TNBC) or HER2-positive breast cancer treated with neoadjuvant chemotherapy (NAC). Patients who self-identified as non-Hispanic white (NHW) or non-Hispanic Black (NHB) and were diagnosed with Stage I-III TNBC (n = 171 including 124 NHW and 47 NHB) and HER2-positive (n = 161 including 136 NHW and 25 NHB) breast cancer who received NAC from 2000 to 2018 at Roswell Park Comprehensive Cancer Center were included. Associations of race with pCR and survival outcomes were evaluated using logistic and Cox regression models, respectively. There was no statistically significant difference in pCR between NHB and NHW patients with TNBC (31.9 vs 29.8%; OR: 1.11, 95% CI 0.54-2.29) or HER2-positive breast cancer (36.0 vs 39.7%; OR: 0.87, 95% CI 0.36-3.11). After controlling for potential confounders, including age, stage, treatment regimens, insurance status, and comorbidities, no statistically significant difference in OS or RFS was observed between NHB and NHW patients within either subtype. TNBC or HER2-positive breast cancer patients treated at a single academic center in Buffalo, NY, showed similar outcomes independent of patients' race. Given the known genetic diversity of African American ancestry in the US, further studies investigating the interplay between race, geography, and clinical outcomes are warranted.

Racial Differences in Clinical Outcomes for Metastatic Renal Cell Carcinoma Patients Treated With Immune-Checkpoint Blockade.

BackgroundImmune-checkpoint-inhibitors (ICIs) have become the cornerstone of metastatic renal-cell-carcinoma (mRCC) therapy. However, data are limited regarding clinical outcomes by race. In this study, we compared the real-world outcomes between African American (AA) and Caucasian mRCC patients treated with ICIs.MethodsWe performed a retrospective study of 198 patients with mRCC who received ICI at the Emory Winship Cancer Institute from 2015-2020. Clinical outcomes were measured by overall survival (OS), progression-free survival (PFS), and overall response rate (ORR) defined as a complete or partial response maintained for at least 6 months per response evaluation criteria in solid tumors version 1.1. Univariate and multivariable analyses were carried out for OS and PFS by Cox proportional-hazard model and ORR by logistical-regression model. Descriptive statistics compared rates of immune-related adverse events (irAEs) and non-clear-cell-RCC (nccRCC) histology were assessed using Chi-square test.ResultsOur cohort was comprised of 38 AA and 160 Caucasian patients. Most were diagnosed with clear-cell-RCC (ccRCC) (78%) and more than half received (57%) PD-1/PD-L1 monotherapy. Most patients were intermediate or poor-risk groups (83%). Comparing to Caucasians, our AA cohort contained more females and nccRCC cases. Kaplan-Meier method showed AAs had no statistically different median OS (17 vs 25 months, p=0.368) and PFS (3.1 vs 4.4 months, p=0.068) relative to Caucasian patients. On multivariable analysis, AA patients had significantly shorter PFS (HR=1.52, 95% CI: 1.01-2.3, p=0.045), similar ORR (OR=1.04, 95% CI: 0.42-2.57, p=0.936) and comparable OS (HR=1.09, 95% CI: 0.61-1.95, p=0.778) relative to Caucasians.ConclusionsOur real-world analysis of ICI-treated mRCC patients showed that AAs experienced shorter PFS but similar OS relative to Caucasians. This similarity in survival outcomes is reassuring for the use of ICI amongst real-world patient populations, however, the difference in treatment response is poorly represented in early outcomes data from clinical trials. Thus, the literature requires larger prospective studies to validate these findings.

Differences in the mutational landscape of triple-negative breast cancer in African Americans and Caucasians.

Triple-negative breast cancer (TNBC) occurs at higher frequency in African Americans compared with Caucasians. It is unclear if the biology of TNBC is different in African American versus Caucasians. In this study, we sought to evaluate racial differences in the molecular pathology of TNBC. Using data from The Cancer Genome Atlas, we identified TNBC patients with information on race. We analyzed differences in clinical characteristics, tumor somatic mutations, and gene expression patterns by race from whole exome and microarray data. 1104 patients were identified, of which 178 had TNBC. TNBC was more frequent in African Americans than Caucasians (33.3 vs 14.9%). Although more African Americans than Caucasians overall were classified as basal-like from PAM50 gene expression (34.8 vs 16.1%), no differences in the TNBC cohort were observed. Median tumor somatic mutation counts were higher in African Americans versus Caucasians (39.5 vs 34), but no racial differences in the mutation counts in TNBC were observed. Somatic mutation analysis revealed racial differences in specific high prevalence genes in all patients (TP53 46% in African Americans vs 27% in Caucasians; PIK3CA 23% in African Americans vs 34% in Caucasians; and MLL3 12% in African Americans vs 6% in Caucasians). TNBC patients did not have any specific high prevalence genes associated with racial differences. There were no racial differences in gene expression patterns in selected genes involved in breast cancer biology. Overall, African Americans had shorter TTP and worse DFS. Racial differences in clinical outcomes were not observed in TNBC. The mutational landscape of TNBC is similar between African Americans and Caucasians. The higher frequency of TNBC in African Americans is therefore not associated with a different genomic profile of commonly established tumor regulatory pathway genes. Other modifiable factors may exist that contribute to the racial disparity in TNBC.

Racial Differences in Outcomes after Acute Ischemic Stroke Hospitalization in the United States

Racial differences in stroke outcomes have major health policy implications. There is paucity of contemporary data on racial differences in clinical outcomes and resource utilization in acute ischemic stroke hospitalizations in the United States. We used the 2011-2012 National Inpatient Sample to identify hospitalizations with a primary diagnosis of acute ischemic stroke. Primary outcomes were in-hospital mortality, utilization of thrombolysis, and endovascular mechanical thrombectomy (EMT). Secondary outcomes were length of stay (LOS) and average inflation-adjusted charges. A total of 173,910 hospitalizations representing 835,811 hospitalizations nationwide were included in the study. Mean age was 70.9 years and 52.3% were women. Blacks (adjusted OR .71, 95% CI .64-.78, P < .001) and Asian or Pacific Islanders (adjusted OR .80, 95% CI .66-.97, P = .02) had a lower in-hospital mortality compared to Whites. Blacks were less likely to be treated with thrombolysis (adjusted OR .84, 95% CI .76-.92, P < .001) and EMT (OR .73, 95% CI .58-.91, P = .01). Average LOS and inflation-adjusted charges were significantly higher for racial minorities compared to Whites. Blacks and Asians hospitalized for ischemic stroke are less likely to die in the hospital compared to Whites. Hospitalization for stroke in Blacks is associated with lower rates of reperfusion therapy, longer lengths of stay, and higher costs compared to Whites.

Abstract 19569: Racial Differences in Clinical Outcomes and Resource Utilization Associated With Acute Myocardial Infarction Hospitalizations in the United States: A Population-wide Analysis From 2011-2012

Background and objectives: Racial-ethnic disparities in cardiovascular diseases are a major public health problem in the US. There are few recent data on racial differences in clinical outcomes and resource utilization associated with acute myocardial infarction (AMI) hospitalizations. Hypothesis: There are significant racial-ethnic differences in AMI hospitalization outcomes. Methods: We used the 2011-2012 Nationwide/National Inpatient Sample to identify primary AMI hospitalizations. Outcomes of interest included in-hospital mortality, utilization of PCI and thrombolysis, inflation adjusted charges and length of stay. Relevant ICD-9 codes were used. Racial-ethnic differences in outcomes were tested using logistic and linear regression models. Results: 228,302 AMI hospitalizations representing 1.1 million hospitalizations nationwide were included in the study. After adjusting for age, sex, HTN, DM, PCI, thrombolysis, socioeconomic status (SES) and APR-DRG mortality risk, Blacks had significantly lower (OR 0.88, 95% CI 0.81 - 0.94; &lt;0.001) and Native Americans significantly higher (OR 1.37, 1.03 - 1.81; p=0.03) case fatality compared to Whites (Model ROC=0.88, p&lt;0.001). Blacks were less likely (OR 0.76, 95% CI 0.72 - 0.80; p&lt;0.001) and other races more likely (OR 1.33, 95% CI 1.23 - 1.43; p&lt;0.001) to undergo PCI adjusted for SES. SES adjusted odds of thrombolysis were lower in Blacks (OR 0.80, 0.67 - 0.97; p&lt;0.001) and higher in Native Americans (OR 3.78, 1.42 - 10.07; p=0.01) compared to Whites. There were significant differences in charges and LOS across races. Conclusions: Blacks hospitalized for AMI are less likely and NA more likely to die in the hospital compared to Whites. Blacks are less likely to receive reperfusion therapy compared to Whites. Future studies should investigate the mechanism of the apparent protective effect of Black race on in-hospital mortality in AMI.

Abstract 19212: Racial Differences in Clinical Outcomes and Resource Utilization Associated With Heart Failure Hospitalizations in the United States: A Nationwide Analysis From 2011-2012

Background and objectives: Heart failure (HF) incidence is higher among Blacks compared to Whites. There is a paucity of recent data on racial differences in in-hospital mortality and resource utilization in a nationally representative, multiracial cohort of HF hospitalizations. Hypothesis: There are significant racial-ethnic differences in HF hospitalization outcomes. Methods: We used the 2011-2012 Nationwide/National Inpatient Sample to identify hospitalizations with a primary diagnosis of HF using relevant ICD-9 codes. Outcomes of interest were in-hospital mortality, length of stay (LOS) and mean inflation adjusted charges. The effect of race on outcomes was ascertained using logistic or linear regression. Results: 375,740 primary HF hospitalizations representing 1.8 million hospitalizations nationwide were included. Mean age was 72.6 (SD 14.6) years and 50.1% were females. After adjusting for age, sex, hypertension, diabetes, APR-DRG mortality risk and socioeconomic status, in-hospital mortality was significantly lower for Blacks (OR 0.69, 95% CI 0.64 - 0.74; p&lt;0.001), Hispanics (OR 0.82, 95% CI 0.75 - 0.91; p&lt;0.001) and Asians or Pacific Islanders (OR 0.85, 95% CI 0.73 - 0.99; p=0.04) compared to Whites. Average inflation adjusted charges were significantly higher for all minorities compared to Whites except for Native Americans for whom charges were significantly lower than Whites (p&lt;0.05 for Black, Hispanic, Asian, NA or Others vs. Whites). LOS was modestly higher for Blacks or Other races vs. Whites (p=0.01 B vs. W and Others vs. W) and lower for Native Americans vs. Whites (p&lt;0.001). Conclusions: Blacks, Hispanics and Asians hospitalized for HF are significantly less likely to die in the hospital compared to Whites. Hospital charges for racial-ethnic minorities are significantly higher compared to Whites. The reasons for racial differences in HF hospitalization outcomes require further investigation.

Abstract 11097: Racial Differences in Clinical Outcomes in Elderly Patients With Atrial Fibrillation

Introduction: Atrial fibrillation (AF) is associated with stroke and death, but the effect of race on these outcomes is not known. Methods: Medicare administrative data from 2010-2011 were used to identify patients with newly diagnosed AF who were categorized based on race as white, black and Hispanic. Racial differences in the primary outcome of death and secondary outcomes of stroke and the composite of stroke and death were assessed using Cox proportional hazard models. Results: Among 517,941 patients with newly diagnosed AF, 452,986 (87%) were whites, 36,425 (7%) were blacks and 28,530 (6%) were Hispanics. The mean age was 79 ± 8 years and 40.5% were males. Over a mean follow-up period of 0.9 years per patient, 68,250 (15.1%) whites, 7665 (20%) blacks and 4814 (16.9%) Hispanics died. Stroke was diagnosed in 6,509 (1.4%) whites, 843 (2.3%) blacks and 507 (1.8%) Hispanics. Compared to whites, blacks had a significantly higher hazard of death (Hazard Ratio [HR] =1.43; 95% CI 1.40-1.47; p&lt;0.001), stroke (HR=1.69; 95% CI 1.57-1.81; p&lt;0.001), and the composite outcome (HR= 1.46; 95% CI 1.43-1.49; p&lt;0.001). After controlling for pre-existing co-morbidities, the higher hazard of death (HR 0.99; 95% CI 0.97-1.01; p=0.41) and the composite outcome (HR=1.02; 95% CI 0.99-1.04; p=0.135) in blacks were eliminated and the relative hazard of stroke (HR=1.44; 95% CI 1.34-1.55; p&lt;0.001) was reduced compared to the whites. Similarly, Hispanics had a higher risk of death (HR= 1.13; 95% CI 1.10-1.17; p&lt;0.001), stroke (HR=1.26; 95% CI, 1.15-1.38; p&lt;0.001) and the composite outcome (HR= 1.15; 95% CI 1.12-1.18; p&lt;0.001), as compared to whites. The relative hazard of death and the composite outcome were noted to be lower in Hispanics, compared to whites, after controlling for pre-existing co- morbidities (HR= 0.93; 95% CI 0.92-0.96; p&lt;0.001 and HR= 0.95; 95% CI 0.92-0.97; p&lt;0.001 respectively). The relative hazard of stroke was also attenuated (HR=1.15; 95% CI 1.05-1.26; p=0.002). Conclusions: In an elderly Medicare population with newly diagnosed AF, the risks of death and stroke are higher in blacks and Hispanics, as compared to whites. This is likely due to increased co-morbidities in blacks and Hispanics.

Benign prostatic hyperplasia: racial differences in treatment patterns and prostate cancer prevalence

• To compare prostate cancer, prostate-related surgery and acute urinary retention rates, as well as associated healthcare resource use over 11 years in African American and Caucasian men with benign prostatic hyperplasia (BPH). • The BPH-related medical and surgical charges and events were determined for 398 African American men and 1656 Caucasian men followed for a mean of 10.2 years within a health maintenance organization. • Racial differences in clinical outcomes were evaluated using time-to-event analysis, stratifying results by baseline prostate-specific antigen (PSA) values. • Risk of a prostate cancer diagnosis was 2.2 times greater in African American than Caucasian men (95% CI 1.48-3.35, P < 0.001) in analyses adjusting for serum PSA level. • Although African Americans were more likely to receive medical therapy for symptoms of BPH than Caucasians (43.5% vs 37.2%, respectively; P= 0.029), there were no clinically meaningful differences with respect to subsequent acute urinary retention or BPH-related surgery between them, or BPH-related medical charges (US $407 vs US $405 per month). • As evidenced by this analysis of 'real-world' clinical practice, African Americans with BPH have a much greater risk of developing prostate cancer than similar Caucasian men highlighting the need for education and early detection in this population.

Exploring racial differences in outcome for metastatic colorectal cancer: Results from a large prospective observational cohort study (BRiTE).

e14039 Background: African-Americans are more likely to be diagnosed with metastatic colorectal cancer at the time of presentation than whites, and have shorter survival once diagnosed. This study examines racial differences in clinical outcomes in the setting of a large observational cohort study. Methods: The study cohort consisted of 1,589 white (81.4%) and 227 African-American (11.6%) patients with metastatic colorectal cancer receiving front line bevacizumab therapy enrolled in a large prospective observational cohort study. Differences in time to event endpoints and response incidence were examined by race. Differences in the incidence of baseline and treatment related toxicities associated with bevacizumab were also examined. Finally, differences in patterns of care by race were explored. Results: Median OS was 22.6 months for African Americans and 22.9 months for whites. Median PFS was 9.5 months for African Americans and 9.8 months for whites. Response rates (CR+PR) were 37.5% for African Americans and 46.3% for whites (Adjusted OR 0.66; 95%CI: 0.49-0.89). African Americans had higher rates of baseline diabetes (18.9% vs. 11%; p = 0.002) and hypertension (52.9% vs. 41.4%; p = 0.001), and worsening hypertension while on therapy (13.7% vs. 8.9%; p = 0.02) but no differences in on-treatment Arterial Thromboembolic Events were seen. Conclusions: This large observational cohort study of patients with metastatic colorectal cancer demonstrates that when treated in a similar fashion with modern chemotherapy, African Americans and whites have equivalent cancer outcomes. Encouragingly, no significant differences in bevacizumab related toxicity or patterns of care were seen between African Americans and whites. The lower response rate among African Americans deserves further study. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Genentech Genentech Genentech Genentech

Racial Differences in Clinical Outcomes From Metastatic Breast Cancer: A Pooled Analysis of CALGB 9342 and 9840—Cancer and Leukemia Group B

African American women are more likely to be diagnosed with metastatic breast cancer at the time of presentation than whites, and have shorter survival once diagnosed. This study examines racial differences in clinical outcomes in the setting of two large cooperative group randomized clinical trials. The study cohort consisted of 787 white (80%) and 195 African American (20%) patients with metastatic breast cancer enrolled in two successive Cancer and Leukemia Group B (CALGB) trials using taxanes in the metastatic setting. Differences in overall survival (OS), response incidence, and time to treatment failure (TTF) were examined by race. In addition, differences in the incidence of baseline and treatment-related toxicities were examined. With 779 deaths (166 African Americans and 613 whites), median OS was 14.3 months for African Americans and 18.75 months for whites (hazard ratio [HR] = 1.37; 95% CI, 1.15 to 1.63). When adjusted for prognostic factors, African Americans had a 24% increase in the hazard of death compared with whites (HR = 1.24; 95% CI, 1.02 to 1.51). No significant differences in TTF or overall response to therapy were seen. No clinically significant toxicity differences were seen. African Americans with metastatic breast cancer have an increased hazard of death compared with whites despite the receipt of similar per-protocol treatment, but experience no differences in TTF or overall response to therapy. We hypothesize that more direct and robust measures of comorbidities, and perhaps other factors such as receipt of subsequent therapy could help further explain the observed survival difference.

Racial Differences in Clinical Outcomes From Metastatic Breast Cancer: A Pooled Analysis of CALGB 9342 and 9840—Cancer and Leukemia Group B

Racial Differences in Clinical Outcomes From Metastatic Breast Cancer: A Pooled Analysis of CALGB 9342 and 9840—Cancer and Leukemia Group B