The results from our study are applicable across a variety of settings; for example, among at-risk pathway signaling youth, women

and hard to reach men in Zimbabwe and Thailand, repeat testing rates were comparable with those found in facilitated testing in high-risk men who have sex with men population in the USA.55 Lugada et al51 demonstrated that men used rapid-testing approaches but that this usage was slightly less than women. This is an important finding because men are usually harder to reach for HIV testing and treatment programmes.14 66 The findings of our review are also similar to a recent meta-analysis that shows increased receipt of HIV testing with rapid HIV VCT in medical facilitities.67 Rapid VCT has emerged as a complex intervention that can be used

in community settings and health facilities in low-income and high-income countries. Previous systematic reviews have not included rapid VCT studies conducted in health facilities, thus leaving rapid VCT approach primarily directed at CB initiatives; for example, the WHO HIV guidelines highlights CB VCT, but not rapid VCT for health facilities. Finally, our study highlights the importance of three key components within a counselling and testing strategy. Complex interventions include components with varying degrees of interaction.68 We suggest ongoing research is needed to improve HIV testing and viral load suppression: and this should include recognition of interacting components within the intervention, the number and difficulty of behaviours required by those delivering or receiving the intervention, the number of organisational levels targeted by the intervention, the number and variability of outcomes, and the degree of flexibility or tailoring of the intervention.69 Understanding this variability is also important for

economic analysis. Implication for policy and practice Our study has shown the benefit of rapid VCT on uptake of HIV testing and receipt of results.70 This testing approach was effective in health facilities as well as community settings. CB VCT has received explicit attention in the recent WHO HIV testing and treatment guidelines and WHO consolidated guidelines for key populations.39 42 Our work supports CB VCT, but AV-951 also finds that persons at high risk of exposure to HIV who use health facilities benefit from rapid VCT. This finding is not yet reflected in the WHO Consolidated Guidelines for key populations.42 We also found some emerging evidence for increased HIV awareness in most care settings.71 Implementing rapid VCT, with testing components tailored for high-risk communities, could improve health equity through earlier HIV diagnosis with possible retention in viral suppression programmes, reduced transmission and longer lifespans.