Decisions about prescribing post-exposure prophylaxis (PEP) against HIV in one Swiss emergency room were not in keeping with prescribing guidelines 22 percent of the time, Reuters Health Reports.

According to current guidelines, four weeks of combination antiretroviral (ARV) treatment are indicated as an emergency means of preventing HIV infection among those who have recently engaged in condomless intercourse with an HIV-positive partner who has a detectable viral load or a partner who is at risk of having the virus but whose HIV status is unknown.

Publishing their findings in the Journal of Acquired Immune Deficiency Syndromes, researchers designed a risk-assessment algorithm to determine whether decisions about PEP prescriptions at the University Hospital Zurich ER were in keeping with PEP guidelines. They analyzed all those who came to the ER reporting recent condomless consensual sex between 2007 and 2013.

A total of 975 people came to the hospital for PEP 1,051 times between them. Eighty-one percent of them were male and 37 percent were men who have sex with men (MSM).

Sixty-one percent of these visits resulted in a prescription for PEP. Seventy-four percent of the prescribing decisions were in keeping with the algorithm, 22 percent were not and 4 percent were of an unknown status.

For 12 percent of these visits, the hospital staff prescribed PEP to people who were not considered at risk for HIV. Ten percent of the visits involved people who were at risk for HIV but did not wind up receiving PEP.

To read the Reuters Health article, click here.

To read the study abstract, click here.