Massachusetts health reform and disparities in joint replacement use: difference in differences study

Area of Science:

• Health Services Research
• Health Policy
• Surgical Outcomes

Background:

• Insurance expansion in 2006 aimed to improve access to healthcare.
• Understanding its impact on elective surgical procedures is crucial for policy evaluation.

Purpose of the Study:

• To assess the effect of Massachusetts' 2006 insurance expansion on knee and hip replacement rates.
• To analyze disparities in procedure use by race/ethnicity and area income.
• To examine changes in the utilization of safety net hospitals for these procedures.

Main Methods:

• A quasi-experimental, difference-in-differences study design was employed.
• Data from Massachusetts residents (ages 40-64) were compared to a control group from neighboring states.
• Multivariate regression analyses adjusted for demographic, socioeconomic, and geographic factors.

Main Results:

• Overall knee and hip replacement use increased by 4.7% in Massachusetts post-reform.
• The increase was significantly greater for Hispanic (37.9%) and Black (11.4%) individuals compared to White individuals (2.8%).
• No significant income-based disparities in procedure use increases were observed. The proportion of procedures in safety net hospitals decreased, especially for Hispanic and low-income patients.

Conclusions:

• Insurance expansion effectively reduced racial/ethnic disparities in access to elective orthopedic surgery.
• The expansion did not mitigate income-based disparities in access.
• A notable shift of elective surgical procedures away from safety net hospitals occurred.