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

To estimate the impact of the insurance expansion in 2006 on use of knee and hip replacement procedures by race/ethnicity, area income, and the use of hospitals that predominantly serve poor people ("safety net hospitals").Quasi-experimental difference in differences study examining change after reform in the share of procedures performed in safety net hospitals by race/ethnicity and area income, with adjustment for patients' residence,...