546 Using Contingency Management to Understand the Cardiovascular, Immune and Psychosocial Benefits of Reduced Cocaine Use: A Protocol for a Randomized Controlled Trial oleh Sean Regnier, Jennifer R. Havens, Thomas P. Shellenberg, David H. Cox, Thomas S. Baker, Joshua A. Lile, Craig R. Rush, Reuben Adatorwovor, Lon R. Hays, Danielle M. Anderson, Mary B. Fisher, Suzanne C. Segerstrom, Joy M. Schmitz, William W. Stoops