Harm Reduction Contingency Management for Stimulant Use Reduction and Antiretroviral Therapy Adherence in HIV Primary Care: Protocol for an Implementation Effectiveness Study - Gabriela Steiner; Stefan Baral; Elise D Riley; Steven Shoptaw; Gabriel Chamie; Kate Roberts; Lauren Suchman; Kelly Knight; Monica Gandhi; Phillip Coffin; Ayesha Appa (JMIR Research Protocols)