Breast, lung, and colorectal cancer patients in Medicaid expansion states saw lower mortality rates compared with patients in nonexpansion states, a new study found.
Medicaid expansion under the Patient Protection and Affordable Care Act was associated with decreased mortality in newly diagnosed breast, lung, and colorectal cancer patients, a new study in JAMA Network Open found.1
Past studies have shown improvements in survival rates after ACA expansion, including in breast cancer patients.2 Authors of the new study pointed out that while Medicaid expansion has been associated with fewer uninsured patients, increased screening, and earlier diagnosis in cancer care, its association with mortality across cancer types was still uncertain.
The authors wrote that they aimed to build upon data showing that Medicaid expansion increased early-stage cancer diagnoses by focusing on 3 questions:
The cross-sectional, quasi-experimental, difference-in-difference (DID), population-based study analyzed data from patients in the National Cancer Database who were newly diagnosed from January 1, 2012, to December 31, 2015. Data was analyzed from January to May 2020.
It included 523,802 patients with breast, lung, or colorectal cancer. Patients were divided into 2 cohorts based on whether they lived in a Medicaid expansion state (289,330 [55.2%]), which had a baseline of early and January 2014, or in a nonexpansion state (n = 234,472 [44.8%]).
Patients in Medicaid expansion states saw a significant decrease in mortality (hazard ratio [HR], .98; 95% CI, 0.97-0.99; P = .008). Those in nonexpansion states, however, did not see a drop in mortality (HR, 1.01; 95% CI, 0.99-1.02; P = .43). The result was a significant DID (HR, 1.03; 95% CI, 1.01-1.05; P = .01). “In general, a DID HR greater than 1 indicates a greater improvement in expansion vs non-expansion states or less worsening in expansion vs nonexpansion states,” the authors wrote.
The rates varied by cancer type, but the trends were similar in each of the cancers. Mortality in lung cancer patients improved in both expansion and nonexpansion states, but it was more significant in Medicaid expansion states, (DID HR, 1.03; 95% CI, 1.00-1.06; P = .03). Both breast and colorectal cancer saw worse mortality across the board, but mortality increased to a lesser degree in expansion states vs nonexpansion states in both cancer types. The difference in DID HR was not significant between breast and colorectal cancer ([DID HR, 1.04; 95% CI, 0.98-1.10; P = .24] and [DID HR, 1.04; 95% CI, 1.00-1.09; P = .08], respectively).
The authors noted that while the only significant decrease in mortality rate was in lung cancer, longer follow-up may find that rates of breast and colorectal cancer also improve, given that lung cancer generally has a higher mortality rate than both breast and lung cancer.
The difference in mortality rates was mostly in patients who were diagnosed with stage I-III cancers. The improvement in mortality in expansion states was not seen once the data was adjusted for cancer stage (HR, 1.00; 95% CI, 0.98-1.02; P = .94).
“The difference between expansion and nonexpansion states in the change in the hazard of death was no longer significant after adjusting for cancer stage (DID HR, 1.00; 95% CI, 0.98-1.02; P = .84),” the authors wrote, “suggesting that survival differences were mediated by cancer stage."
The study did not find any significant differences in mortality rates among at-risk populations, including Black patients and patients living in areas within the lowest quartile of income. Limitations included the observational nature of the study and a lack of patient-level information, including state of residence or eligibility for Medicaid.
The authors concluded that Medicaid expansion was associated with a decrease in mortality from cancer, citing access to screening and early diagnoses as possible drivers in that trend. Even so, additional studies are needed to help researchers understand why there was a baseline mortality difference between patients in expansion vs nonexpansion states and whether the mortality rate differences persist.
1. Lam MB, Phelan J, Orav EJ, et al. Medicaid Expansion and Mortality Among Patients With Breast, Lung, and Colorectal Cancer. JAMA Netw Open. Published online November 5, 2020. doi:10.1001/jamanetworkopen.2020.24366
2.Shaw M. Study Results Show Possible Link Between Medicaid Expansion, Drop in Advanced Breast Cancer. The American Journal of Managed Care®. July 1, 2020. Accessed November 5, 2020. https://www.ajmc.com/view/study-results-show-possible-link-between-medicaid-expansion-drop-in-advanced-breast-cancer-