The association of Medicaid expansion and parathyroidectomy for benign disease: Insurance status remains an important factor in access to high-volume centers.

BACKGROUND

Medicaid expansion has been associated with improved access to surgical care at high-volume centers. Its impact on parathyroidectomy, however, is unclear. We evaluated the association between Medicaid expansion and parathyroidectomy at high- and low-volume centers.

METHODS

The Vizient Clinical Data Base was queried for parathyroidectomies. Patients were grouped by insurance status and pre- and post-Medicaid expansion periods. Hospitals were stratified into tertiles (T1-T3) by operative volume (T1 = highest-volume centers). Odds of parathyroidectomy and a difference-in-differences analysis were conducted.

RESULTS

In total, 31,983 patients were identified. Patients were predominantly privately insured (49.9%). Uninsured and Medicaid patients had increasing odds of operation at lower-tertile centers (odds ratio: T1 = ref; uninsured: T2 = 10.0, T3 = 15.8; Medicaid: T2 = 6.2, T3 = 13.5; P < .001). Medicare patients, however, were less likely to undergo operation at lower-volume centers (odds ratio: T2 = 0.89, P < .001; T3 = 0.92, P = .002). Privately insured patients were the least likely to receive care at low-volume centers (odds ratio: T3 = 0.7, P < .001). Medicaid patients in nonexpansion states had 12-16 times higher odds of parathyroidectomy at lower-volume hospitals than their counterparts in expansion states (expansion/nonexpansion states: pre-expansion T3 = 2.3/28.0; postexpansion T3 = 1.3/21.4). Expansion was associated with an increase in the proportion of parathyroidectomy for Medicaid patients, with larger gains seen at higher-volume centers (T1 = 5.0%, P = .01; T2 = 3.1%, P = .001; T3 = 2.7%, P = .03). Expansion was not associated with changes in payor distribution for uninsured, Medicare, or privately insured patients.

CONCLUSIONS

Medicaid expansion was associated with an increase in parathyroidectomy for Medicaid patients at high-volume centers. However, in nonexpansion states, access to surgical treatment at high-volume centers remains limited for uninsured and underinsured patients.