Talking about home testing for HIV

Tell your story




False Negatives

I recently did 2 biosure hiv self tests at 6 months. Only the control line was visible in both tests and I even got someone else to see my results to make sure my eyes were not seeing things. Is there a chance of them being false negatives?

5 Responses

Becky Smith, BioSURE UK LTD
 Work on 22nd June 2020

Hi Curious, Yes, sorry our test has a clinical SENSITIVITY of 99.7% and a clinical SPECIFICITY of 99.9%. On average 997 positive cases will be detected in every thousand tests. Sorry for my previous post and thank you for correcting me. Kindest regards, Becky

 Used on 20th June 2020

I'm sorry but can I ask, in relation to your post, it says on your website that it has clinical sensitivity of 99.7% not 99.9%, which is the specificity? Effectively 3 out of every 1000 hiv positive people taking test may get false negative results with 99.7% sensitivity, including outside the window. Is this correct?

Becky Smith, BioSURE UK LTD
 Work on 19th June 2020

Hi Nicholas, The BioSURE HIV self test has a clinical sensitivity of 99.9% so essentially every 1 in 1000 negative results are false. The window period is 12 weeks, anyone is welcome to test at any time during this window period but we always recommend to retest at 12 weeks for a conclusive result. False negative results are more common when testing inside the window period as if a persons body has not produced antibodies in response to the virus, the test will not be able to detect this and therefore may give a negative result when in fact the person is HIV positive. False negative results have also been reported when a person is taking antiretroviral treatment, such as PEP or PrEP. This is due to the ART medication inhibiting HIV viral replication and subsequently lowering the viral load - this in turn reduces the production of antibodies and therefore the test will not be able to accurately give a reliable result. We recommend to wait 12 weeks after finishing any course or PrEP or PEP to test. Again, the rate of false negatives is 99.9% for the BioSURE HIV self test. I hope this information helps. Becky

 Used on 17th June 2020

What percentage of a false negative is due to it being within the window period? What are the other possible causes of a potential false negative and how likely are they to occur?

Becky Smith, BioSURE UK LTD
 Work on 16th June 2020

Hi Learning, The likelihood of both tests (performed well outside of the window period) being false negatives is around 1 in a million. Usually only false negative results occur when users test inside of the window period. I would be very confident in your negative results and hopefully you can try to put this behind you and move on. Kindest regards, Becky

Post Your Response

  • Tell us your story
  • Label your post

Step 1. Tell your story

Feel free to complete the form below in your own words - write as much or as little as you like! Your comments will be appear anonymously on PEBL.