Medicaid Associated With Reduction in Racial/Ethnic Disparities in De Novo Stage IV Breast Cancer

Patients in racial and ethnic minority groups had a reduction in 2-year mortality compared with patients who were White with de novo stage IV breast cancer following implementation of Medicaid expansion, according to a cross-sectional study published in JAMA Oncology.

Investigators reported a 2-year mortality reduction of 32.2% in the pre-expansion period and 26.0% in the post-expansion period in areas that received a Medicaid expansion. The adjusted 2-year mortality dropped from 40.6% to 36.3% for White patients and 45.6% to 35.8% for those in racial and ethnic minority groups (adjusted difference-in-difference, –5.5%; 95% CI, –9.5 to –1.6; P = .006). For the overall study population, the 2-year mortality rate was 29.4%, which was indicative of a decrease from 33.6% in 2010 to 25.6% in 2015 (P <.001).

“In this cross-sectional study, we observed a significant increase in [overall survival] and a decrease in 2-year mortality among patients with de novo stage IV breast cancer residing in states that expanded their Medicaid program in January 2014…. While similar trends have been reported, our study is, to our knowledge, unique because it examines the association between Medicaid expansion and decreased racial disparities,” investigators of the study wrote.

A total of 9322 patients were included in the study, of whom 5077 were diagnosed in the pre-expansion period and 4245 were diagnosed in the post-expansion period. Overall, 27.3% of the total population was part of a racial or ethnic minority group, and 72.2% of patients were White. In particular, 5.4% of patients were Hispanic (any race), 16.3% were non-Hispanic Black, 0.3% were American Indian or Alaska Native, 3.8% were Asian or a Pacific Islander, and 1.6% were unknown. Medicaid expansion was associated with a lower number of uninsured patients, from 6.7% in the pre-expansion group to 3.6% in the post-expansion group.

The median follow-up was 2.5 years, and the median overall survival was 3.2 years (95% CI, 3.0-3.4). For patients who were White, the Kaplan-Meier estimated 2-year OS rate was 64% vs 56% among those in the racial and ethnic minority group (P <.001). Notably, the OS rate between the 2 racial groups was no longer statistically significant post expansion, with a rate of 71.0% in the ethnic and racial group compared with 71.8% in those who were White (P = .95).

The multivariable Cox proportional hazards regression model highlighted an increased risk of death in the pre-expansion group for patients who were in the racial and ethnic minority group compared with those who were White (adjusted HR [aHR], 1.22; 95% CI, 1.10-1.35; P <.001). For the post-expansion period, the risk of death between the 2 groups was no longer significant (aHR, 0.96; 95% CI, 0.86-1.08; P = .51).

The subgroup analysis consisted of 1510 patients from the lowest income quartile. Findings indicated that the racial and ethnic minority group with a lower income had an increased risk of death vs those who were White in the pre-expansion period (aHR, 1.28; 95% CO, 1.01-1.61), although the risk decreased in the post-expansion period (aHR, 0.75; 95% CI, 0.59-0.95). Those in the racial and ethnic minority group who were within the lowest income quartile had a greater reduction in 2-year mortality with the adjusted difference-in-difference of –12.8% (95% CI, –22.2 to –3.5; P = .007) vs the White group.

“Our results highlight the potential positive impact of policies aimed at improving equity and increasing access to health care, suggesting that survival could be improved if Medicaid expansion is implemented by other states,” the investigators concluded.

Reference

Malinowski C, Lei X, Zhao H, Giordano SH, Chavez-MacGregor M. Association of Medicaid expansion with mortality disparity by race and ethnicity among patients with de novo stage IV breast cancer. JAMA Oncol. 2022;8(6):863-870. doi:10.1001/jamaoncol.2022.0159