Review shows HIV self-testing to be acceptable, accurate and feasible, but finds little data on linkage to care for those testing HIV positive

Michael Carter
Published: 04 April 2013

Self-testing for HIV is highly acceptable to people in a variety of settings, investigators report in the open-access journal PLoS Medicine. The authors reviewed the results of 21 separate studies and found an acceptability rate of up to 100%. Self-testing using point-of-care assays generally provided accurate results, and there was no evidence that a positive test would lead to a major adverse event such as suicide. However, the investigators could only identify one study that looked at linkage to care following a positive result using self-testing.

“More data from diverse settings and preferably from randomized controlled trials must be collected before any initiatives for global scale-up of self-testing for HIV infection are implemented,” the journal’s editor cautions.

Many HIV infections are undiagnosed. This is a major concern globally. Late diagnosis is associated with high mortality rates, and there is good evidence that large numbers of onward HIV transmissions originate in undiagnosed individuals.

Testing is therefore central to HIV treatment and prevention initiatives. Possible obstacles to testing include the inconvenience of visiting a healthcare facility and a fear of the stigma that many associated with HIV services.

Self-testing could provide a way of overcoming these barriers, and in July 2012 the Food and Drug Administration in the US approved the oral ­OraQuick point-of-care test for over-the-counter sale.

However, little is known about the acceptability, accuracy and consequences of self-testing.

A team of investigators therefore searched databases of published research and conference presentations to identify studies looking at these issues. A total of 21 separate studies conducted between 2000 and 2012 were identified. Only one was a randomised controlled trial, the rest had an observational design.

Two-third of the studies evaluated oral self-testing, the others finger-prick testing. Fourteen studies were concerned with supervised self-testing, a strategy where a healthcare professional provides support throughout the testing process, even though the actual test is performed by the person testing. The remaining studies were unsupervised, with counselling and linkage to care offered via a method such as a helpline.

Three-quarters of the studies were conducted in high-income countries, the remainder in resource-limited settings. They involved diverse populations, ranging from groups with a high HIV risk, such as non-monogamous gay men in US cities, to lower-risk groups in the general population.

Overall, acceptability was high.

Acceptability of supervised testing ranged from 74% among US gay men to 100% among Canadian students. The acceptability of unsupervised testing was documented in two studies, and ranged from 78% among healthcare professionals in Kenya to 84% in non-monogamous US urban gay men.

The results provided by self-testing were, on the whole, highly accurate. Both supervised and unsupervised self-testing accurately determined when a person was HIV negative, and false-negative results were almost unheard of. Although rare, false-positive results were occasionally recorded, and were slightly more common with unsupervised testing, with a rate as high as 7% in one US study.

Self-testing was shown to be feasible, with 95% of US urban gay men reporting that unsupervised testing kits were “very easy to use”.

The frequency of operational errors varied from 0.37% to 5%, the higher rate relating to a Spanish study evaluating unsupervised testing.

Common errors included:

  • Failing to place oral test device in developer solution after swabbing.

  • Removing the test kit from the developer solution too early.

  • Spilling the developer solution.

  • Dipping the testing device in the developer before swabbing.

A small number of individuals also reported difficulty interpreting the testing device or were unable to read or interpret a faint or weakly positive test line on the testing device.

Across all settings, and for both  supervised and unsupervised strategies, motivations for self-testing were:

  • Convenience.

  • Speed and time to obtaining result.

  • Privacy.

  • Sense of control and empowerment.

Approximately two-thirds of people preferred oral to finger-prick tests.

Low-income populations in all settings tended to prefer free self-testing kits, whereas a cost of up to $20 was generally acceptable for more affluent individuals. “This finding implies that the price of a self-testing kit will be an important factor in determining the uptake of self tests,” comment the authors. “This is crucial to policy initiatives.”

Only one study (on unsupervised testing) reported on linkage to care after a positive result. The rate was high, with 96% of individuals testing HIV positive stating they would seek post-test counselling. “Linkages could be better documented in the next phase of controlled studies,” the investigators suggest. “At all times…linking positive self-test results within an 8-24 h window period to post-test counselling followed by CD4 count and ART initiation should…be emphasized.”

Evidence of extreme adverse outcomes, such as suicide following an HIV-positive result, were “entirely absent”.

The authors conclude “self-testing offers an alternative for individuals who desire privacy and confidentiality to find out their sero-status…it offers the potential to bring more people to self-screen and proactively seek linkage to care and prevention, but its potential in optimizing linkages remains unproven.”

Reference

Pant Pai N et al. Supervised and unsupervised self-testing for HIV in high- and low-risk populations: a systematic review. PLoS Medicine, 10:4, e1001414.