Health Care Expenditures Among Adults With Diabetes After Oregon's Medicaid Expansion

Abstract

Objective: To compare trends in Medicaid expenditures among adults with diabetes who were newly eligible due to the Affordable Care Act (ACA) Medicaid expansion to trends among those previously eligible.

Research design and methods: Using Oregon Medicaid administrative data from 1 January 2014 to 30 September 2016, a retrospective cohort study was conducted with propensity score-matched Medicaid eligibility groups (newly and previously eligible). Outcome measures included total per-member per-month (PMPM) Medicaid expenditures and PMPM expenditures in the following 12 categories: inpatient visits, emergency department visits, primary care physician visits, specialist visits, prescription drugs, transportation services, tests, imaging and echography, procedures, durable medical equipment, evaluation and management, and other or unknown services.

Results: Total PMPM Medicaid expenditures for newly eligible enrollees with diabetes were initially considerably lower compared with PMPM expenditures for matched previously eligible enrollees during the first postexpansion quarter (mean values $561 vs. $793 PMPM, P = 0.018). Within the first three postexpansion quarters, PMPM expenditures of the newly eligible increased to a similar but slightly lower level. Afterward, PMPM expenditures of both groups continued to increase steadily. Most of the overall PMPM expenditure increase among the newly eligible was due to rapidly increasing prescription drug expenditures.

Conclusions: Newly eligible Medicaid enrollees with diabetes had slightly lower PMPM expenditures than previously eligible Medicaid enrollees. The increase in PMPM prescription drug expenditures suggests greater access to treatment over time.

© 2019 by the American Diabetes Association.

Figures

Figure 1

Trends in total expenditures of previously and newly eligible Oregon Medicaid recipients with diabetes, matched sample with full enrollment. The figure shows total Medicaid expenditures for previously and newly insured Oregon Medicaid recipients with diabetes between January 2014 and September 2016 using the matched sample of those enrolled throughout the study period. Vertical bars show 95% CIs. SEs are based on regression models (see Supplementary Data for details). Q, quarter.

Figure 2

Trends in inpatient expenditures for previously and newly insured Oregon Medicaid recipients with diabetes, matched sample with full enrollment. The figure shows inpatient Medicaid expenditures of previously and newly eligible Oregon Medicaid recipients with diabetes between January 2014 and September 2016 using the matched sample of those enrolled throughout the study period. Vertical bars show 95% CIs. SEs are based on regression models (see Supplementary Data for details). Q, quarter.

Figure 3

Trends in prescription drug expenditures of previously and newly eligible Oregon Medicaid recipients with diabetes, matched sample with full enrollment. The figure shows prescription drug Medicaid expenditures of previously and newly eligible Oregon Medicaid recipients with diabetes between January 2014 and September 2016 using the matched sample of those enrolled throughout the study period. Vertical bars show 95% CIs. SEs are based on regression models (see Supplementary Data for details). Q, quarter.