Comparison of Low-Value Care in Medicaid vs Commercially Insured Populations

Abstract

Importance: Reducing unnecessary tests and treatments is a potentially promising approach for improving the value of health care. However, relatively little is known about whether insurance type or local practice patterns are associated with delivery of low-value care.

Objectives: To compare low-value care in the Medicaid and commercially insured populations, test whether provision of low-value care is associated with insurance type, and assess whether local practice patterns are associated with the provision of low-value care.

Design, setting, and participants: This cross-sectional study of claims data from the Oregon Division of Medical Assistance Programs and the Oregon All-Payer All-Claims database included Medicaid and commercially insured adults aged 18 to 64 years. The study period was January 1, 2013, through December 31, 2013.

Main outcomes and measures: Low-value care was assessed using 16 claims-based measures. Logistic regression was used to test the association between Medicaid vs commercial insurance coverage and low-value care and the association between Medicaid and commercial low-value care rates within primary care service areas (PCSAs).

Results: This study included 286 769 Medicaid and 1 376 308 commercial enrollees in 2013. Medicaid enrollees were younger (167 847 [58.5%] of Medicaid enrollees were aged 18-34 years vs 505 628 [36.7%] of those with commercial insurance) but generally had worse health status compared with those with commercial insurance. Medicaid enrollees were also more likely to be female (180 363 [62.9%] vs 702 165 [51.0%]) and live in a rural area (120 232 [41.9%] vs 389 964 [28.3%]). A total of 10 304 of 69 338 qualifying Medicaid patients (14.9%; 95% CI, 14.6%-15.1%) received at least 1 low-value service during 2013; the corresponding rate for commercially insured patients was 35 739 of 314 023 (11.4%; 95% CI, 11.3%-11.5%). No consistent association was found between insurance type and low-value care. Compared with commercial patients, Medicaid patients were more likely to receive low-value care for 10 measures and less likely to receive low-value care for 5 others. For 7 of 11 low-value care measures, Medicaid patients were significantly more likely to receive low-value care if they resided in a PCSA with a higher rate of low-value care for commercial patients.

Conclusions and relevance: Oregon Medicaid and commercially insured patients received moderate amounts of low-value care in 2013. No consistent association was found between insurance type and low-value care. However, Medicaid and commercial rates of low-value care were associated with one another within PCSAs. Low-value care may be more closely related to local practice patterns than to reimbursement generosity or insurance benefit structures.

Figure 1. Low-Value Care Risk Differences Associated With Medicaid vs Commercial Insurance Coverage

Risk differences were calculated as the predicted probability of receiving low-value care with Medicaid insurance minus the predicted probability of receiving low-value care with commercial insurance for the average qualifying patient. Models were adjusted for patient age, sex, rural or urban residence, and Charlson comorbidity index. Dots indicate calculated risk differences; error bars, 95% CIs. The P values test for a significant difference between insurance types. CT indicates computed tomography.

Figure 2. Low-Value Care Risk Differences Associated With the Average Medicaid Patient Moving to a Primary Care Service Area (PCSA) With a 1%Higher Commercial Low-Value Care Rate

Risk differences were calculated from logistic regression models, as the change in predicted probability of receiving low-value care for the average qualifying Medicaid patient, when the commercial rate of low-value care in their PCSA of residence increases by 1%. Models were adjusted for patient age, sex, rural or urban residence, and Charlson comorbidity index. Dots indicate calculated risk differences; error bars, 95%CIs. The P values test for a significant difference between residing in one PCSA compared with another PCSA with 1% higher commercial low-value care rates.