Academics from Royal Holloway, University of London, have carried out the largest global review of psychological barriers behind HIV testing and the factors that may influence people's decision to be tested.

The findings, published in the leading journal, AIDS and Behaviour, reveal fear about HIV and HIV testing is one of the biggest barriers to testing, resulting in more than half of the 35 million people infected with HIV not being diagnosed.

Dr Michael Evangeli, from the Department of Psychology at Royal Holloway, who led the study, said: "Our research shows it is imperative that more is done to reduce the fear of HIV and HIV testing to increase the amount of people being tested. A test for HIV, which can now be done in private at home, is necessary to receive HIV treatment and care. The earlier this can be done helps to reduce the onward transmission of HIV. The fact that HIV is treatable needs to be stressed."

One quarter of the over 100,000 HIV positive people in the UK, do not know that they are infected. As well as not having access to the right care and treatment these people are at risk of spreading the condition further.

Study: Which Psychological Factors are Related to HIV Testing? A Quantitative Systematic Review of Global Studies, Dr Michael Evangeli, Kirsten Pady, Abigail L. Wroe, AIDS and Behaviour, doi: 10.1007/s10461-015-1246-0, published online 13 November 2015.