JU INSIGHT Impact of Medicare Low-income Subsidy on Treatment Access, Choice, and Outcomes in Prostate Cancer

By: Daniel D. Joyce, MD, Mayo Clinic, Rochester, Minnesota; Xuanzi Qin, PhD, MSPH, Vanderbilt University Medical Center, Nashville, Tennessee; Vidit Sharma, MD, Mayo Clinic, Rochester, Minnesota; Stephen A. Boorjian, MD, Mayo Clinic, Rochester, Minnesota; Daniel A. Barocas, MD, MPH, FACS, Vanderbilt University Medical Center, Nashville, Tennessee; Stacie B. Dusetzina, PhD, Vanderbilt University Medical Center, Nashville, Tennessee; Kelvin A. Moses, MD, PhD, FACS, Vanderbilt University Medical Center, Nashville, Tennessee | Posted on: 19 Sep 2023

Joyce DD, Qin X, Sharma V, et al. The impact of Medicare low-income subsidy on access to treatment, treatment choice, and oncologic outcomes in patients with metastatic prostate cancer. J Urol. 2023;210(3):447-453.

Study Need and Importance

The number of treatment options for men with advanced prostate cancer has grown significantly over the past 20 years. As oral hormonal therapy use has increased, so have the costs of these drugs for patients and health plans. The low-income subsidy (LIS) for Medicare prescription drug coverage program provides oral cancer drug cost-sharing support for low-income beneficiaries. Whether receipt of LIS is associated with greater uptake of more expensive oral hormonal therapy for men with advanced prostate cancer is unknown.

What We Found

Of the 5,929 patients with advanced prostate cancer identified in the Surveillance, Epidemiology, and End Results–Medicare linked data set, 1,766 (30%) had LIS. On multivariable analysis, those with LIS were more likely to receive oral as opposed to IV treatments compared to patients without LIS (see Table). However, patients with LIS were less likely to initiate any nonandrogen deprivation therapy supplementary systemic therapy (oral or IV) compared to those without LIS. Additionally, patients with LIS experienced worse overall survival than those without LIS.

Table. Characteristics Associated With Oral Over IV First Treatment Choice (Other Than Androgen Deprivation Therapy) Among Patients With Metastatic Prostate Cancer Receiving Nonandrogen Supplementary Systemic Therapies for Metastatic Prostate Cancer (Linear Probability and Logistic Regression Model Results)

	Receipt of oral nonandrogen supplementary systemic therapy (linear probability model)			Receipt of oral nonandrogen supplementary systemic therapy (logistic regression model)
	% Probability difference	95% CI	P value	Odds ratio	95% CI	P value
No low-income subsidy	Ref			Ref
Low-income subsidy	17	(12, 22)	< .001	2.47	(1.86, 3.28)	< .001
Abbreviations: CI, confidence interval; Ref, reference.

Limitations

Our study is limited by the inability to account for prostate cancer disease burden, patient and physician treatment preferences, and patient-specific contraindications that may have influenced treatment decision-making. Our findings should be interpreted in the context of a historical study period. Additionally, we were unable to assess the utilization of other drug assistance programs that may have influenced a patient’s ability to receive higher-cost treatments.

Interpretation for Patient Care

These findings highlight the need for continued efforts to overcome obstacles to health care access and treatment diffusion in low-income patients. Policy changes that reduce and cap out-of-pocket costs for orally administered anticancer treatments covered under Medicare Part D could reduce financial toxicity and improve uptake of these treatments among individuals not eligible for current subsidies.