Study protocol: a mixed-methods study of the implementation of doula care to address racial health equity in six state Medicaid programs oleh Marian Jarlenski, Susan Kennedy, Annaliese Johnson, Caroline Hale, Zoe D’Angelo, Aza Nedhari, Gerria Coffee, Molly Chappell-McPhail, Kiddada Green, Dara D. Méndez, Leigh G. Goetschius, Sarah Gareau, Kristin Ashford, Andrew J. Barnes, Katherine A. Ahrens, Kara Zivin, Elizabeth Mosley, Lu Tang, Writing Committee for Medicaid Outcomes Distributed Research Network