A pilot project, PrEP@Home, reduced clinic visits to one a year and demonstrated that men who have sex with men in three US cities were able to carry out all necessary sampling for tests at home, finding the experience of using the PrEP@Home package acceptable, investigators report in the online edition of Clinical Infectious Diseases.
Prescription of pre-exposure prophylaxis (PrEP) by a healthcare provider requires regular testing for HIV and creatinine levels, as well as testing for sexually transmitted infections and monitoring of behavioural risks. People who obtain PrEP informally, through online purchases, are advised to obtain clinical monitoring too.
HIV antibody testing is essential to determine that a person is HIV negative before using PrEP, and should be repeated on a regular basis to ensure that PrEP is not being used in the presence of HIV infection. Taking PrEP after HIV infection could result in the development of resistance to the drugs used in PrEP – tenofovir and emtricitabine – limiting future antiretroviral treatment options.
Creatinine monitoring before starting PrEP is recommended in order to determine whether a person has reduced kidney function. Regular monitoring of kidney function when taking PrEP is recommended for people over 40 and anyone with reduced kidney function or conditions that might lead to reduced kidney function, such as hypertension or diabetes. Less frequent monitoring is recommended for all other users.
Regular monitoring is also needed to assess adherence to PrEP and to identify any adverse events and to check that PrEP is still needed.
Both US Centers for Disease Control and Prevention and British HIV Association guidelines recommend that people taking PrEP should attend a clinic every three months for monitoring. However, quarterly monitoring places a burden on people taking PrEP and healthcare providers. One US study found that almost half of people who started a course of PrEP did not attend the clinic six months later and there were no demographic or insurance differences between those who did or did not attend a six-month follow-up visit, suggesting that convenience may have been a factor in non-attendance.
The investigators on the PrEP@Home study estimate that if everyone in the United States who is eligible for PrEP started to use it, the healthcare system would need to accommodate an extra five million patient visits each year.
The PrEP@Home study offered a package of self-collected specimens, laboratory testing of specimens and online behavioural questionnaire to replace three out of four quarterly clinic visits.
Participants received a box containing specimen self-collection tests, written instructions and a link to an instructional video, a prepaid mailing envelope to send back their specimens and the number of a 24-hour helpline for assistance.
The self-collection tests gathered samples to test for gonorrhoea and chlamydia by urine sample, rectal swab and pharyngeal swab. Participants were also asked to collect a sample of whole blood by finger-prick sampling to be used for HIV antibody testing, syphilis testing and creatinine testing.
Participants also answered questions on a secure online platform about behaviours that might put them at risk of HIV, medication side-effects, PrEP adherence, potential symptoms of sexually transmitted infections or acute HIV infection, and acceptability of the PrEP@Home package.
The pilot study of the package recruited 58 people but two withdrew due to difficulties in collecting blood samples and one was lost to follow-up. Seventy-eight per cent of participants were under 40 years old, just over half were white, 22% were black and 11% Asian.
Thirty-three out of 55 had been on PrEP for less than a year. Adherence was reported to be good: 75% reported having missed no doses of PrEP in the previous week.
Two participants were unable to prick their fingers to collect blood and two returned inadequate specimens for testing. The remainder (53/57) were able to have their prescriptions renewed.
None tested positive for HIV or syphilis but two participants had rectal gonorrhoea and two had pharyngeal gonorrhoea.
Participants were satisfied with the experience of using the PrEP@Home kit: 85% said that they would use it in preference to a standard clinic visit in the following year if it was available. When asked about individual elements of the sampling process, rectal sampling was considered unacceptable or very unacceptable by seven out of 55 and blood collection by finger prick as unacceptable or very unacceptable by 10 out of 55. Around one-third of participants thought that they would be more likely to remain on PrEP if they could use PrEP@Home in the future.
A larger randomised trial will explore the effect of PrEP@Home on retention in care and adherence to PrEP in four US cities. The trial is due to begin in September 2018 in four cities but will not report results for several years.
By Keith Alcorn
Siegler A et al. Developing and assessing the feasibility of a home-based PrEP monitoring and support program. Clin Infect Dis, advance online publication, 4 July 2018.