1014 - Radiotherapy Utilization and Spending in Patients with Traditional Medicare Compared to Medicare Advantage

J. S. Hogan¹, J. Zheng², T. Zhang³, E. J. Orav⁴, and M. Lam⁵; ¹Washington University School of Medicine, St. Louis, MO, ²Harvard T.H. Chan School of Public Health, Boston, MA, ³Department of Radiation Oncology, Brigham and Women’s Hospital/Dana-Farber Cancer Institute, Boston, MA, ⁴Department of Medicine, Brigham and Womens Hospital, Boston, MA, ⁵Department of Health Policy and Management, Harvard T.H. Chan School of Public Health, Boston, MA

Purpose/Objective(s): Medicare Advantage (MA) plans have seen increased patient enrollment, with 50% penetration in 2022. On a national level, MA plans have shown lower utilization and may represent an opportunity for increasing the value of care. However, there are concerns over limited networks and high coinsurance or copays. To our knowledge, MA utilization in radiation oncology (RO) has not yet been documented. We aim to quantify the use of different treatment modalities, number of fractions, and spending for patients on MA compared to Traditional Medicare (TM). Materials/

Methods: Using 2018 national MA encounter data and TM fee-for-service claims, we identified patients with cancer receiving radiation therapy (RT). We followed the Centers for Medicare and Medicaid algorithm for creating 90-day RT episodes. Each episode was assigned a treatment modality (2-dimensional/3-dimensional [2D/3D], intensity-modulated radiation therapy [IMRT], proton beam, stereotactic, or brachytherapy). Total RT fractions were calculated by summing the number of RT delivery codes during the episode. Mean 90-day RT spending for TM vs. MA patients was calculated. Direct spending data are not available for MA patients; however, HCPCS and derived MS-DRG codes were used to estimate the cost per episode as if that episode had been priced under TM, as per prior studies. The top 0.5% of fractions per episode, and the top and bottom 1% of cost were Winsorized. For each outcome (modality, number of fractions, and cost), predicted means from linear regression were used to calculate outcomes adjusted by cancer type.

Results: There were 34,426 total 90-day episodes eligible for inclusion. A total of 30,944 episodes were included— 22,163 TM and 8,781 MA (3,482 episodes were excluded due to incomplete data). Overall, MA episodes had a higher average number of fractions and average cost than TM episodes (p<0.0001 for both). A comparison of modality, fractions, and RT cost per episode for MA compared to TM is shown in the Table.

Conclusion: These results provide the first nationwide quantification of MA utilization in RO. We found that, overall, MA patients had a higher number of fractions and higher average spending than TM patients. As MA enrollment increases, further research is needed to better understand the impact of MA on RO and cancer patients. Table. Choice of modality, mean number of fractions, and mean RT cost per episode by primary treatment modality for TM and MA. *The number of proton episodes was too small for stable estimates, so proton cost was not estimated and excluded from the overall cost analysis.

	% episodes by modality		# of fractions		RT cost
	TM	MA	TM	MA	TM	MA
Overall	100%	100%	19.4	21.3	$8007	$8417
2D/3D	42.29%	44.07%	15.9	17.2	$3932	$4282
IMRT	36.71%	37.58%	30.8	33.4	$13,429	$14,008
Proton	1.67%	0.59%	31.9	36.7	—*	—*
Stereo	15.28%	14.00%	3.9	4.3	$7513	$7586
Brachy	3.88%	3.61%	7.2	7.6	$3209	$3766