S Citation: Mukumbang FC, van Belle S, Marchal B, van Wyk B (2016) Towards Developing an Initial Programme Theory: Programme Designers and Managers Assumptions on the Antiretroviral Treatment Adherence Club Programme in Primary Health Care Facilities in the Metropolitan Area of Western Cape Province, South Africa. PLoS ONE 11(8): e0161790. doi:10.1371/journal. pone.0161790 Editor: Omar Sued, ARGEN