Point of care Xpert MTB/RIF versus smear microscopy for tuberculosis diagnosis in southern African primary care clinics: a multicentre economic evaluation oleh Anil Pooran, PhD, Grant Theron, PhD, Lynn Zijenah, PhD, Duncan Chanda, MD, Petra Clowes, MD, Lawrence Mwenge, MSc, Farirai Mutenherwa, MSc, Paul Lecesse, MD, John Metcalfe, MD, Hojoon Sohn, PhD, Michael Hoelscher, MD, Alex Pym, PhD, Jonny Peter, PhD, David Dowdy, PhD, Keertan Dheda, PhD