This paper by Katherine Lamp et al, 2019, outlines an analysis of point-of-care (POC) CD4 invalid result rates across five countries. The authors found that the rate of invalid results was consistent across all types of health facilities, and the invalid rates were inversely correlated to operator usage, with high-volume operators. They concluded that POC CD4 testing can, therefore, be performed in decentralized national testing programs; however, adequate training, quality assurance, routine monitoring, and ongoing mentorship should also be implemented for success.