1. VA Center for Implementation Practice and Research Support, VA Greater Los Angeles Healthcare System, 16111 Plummer Street, Sepulveda, Los Angeles, CA 91343, USA
2. Military Medical Research Program, Samueli Institute, Corona del Mar, CA, USA
3. Chiropractic Program, Patient Care Services, Veterans Health Administration, Washington, DC, USA
4. Chiropractic Service, VA Connecticut Healthcare System, West Haven, CT, USA
5. RAND Corporation, Boston, MA, USA