How to make sure people follow the self-test procedure at home

Antigen self-tests are reliable when done as instructed, and most wrong results come from the procedure rather than the kit: a shallow swab, a sample read too early or too late, drops in the wrong well, a test done days after symptoms started. For an organisation, the question is not only whether the test was done but whether it was done properly.

What goes wrong most often

Swabbing too briefly or not deep enough. Not waiting the full development time, or reading after the window has closed. Using the wrong number of drops. Confusing the control line with a result. Testing the wrong person, deliberately or not. Using an expired or damaged kit.

Why organisations turned to supervision

Every regulator that wanted trustworthy self-tests required a witness: a pharmacist in France, a trained supervisor in Germany, a proctor over video for travel. A witness catches procedural errors and confirms identity. The cost of the witness is why supervised programmes ended when the emergency did.

What to require instead of a witness

A programme that wants correct tests without a witness should require four things: that the test is performed on camera so the procedure is recorded rather than described; that the person's identity is confirmed; that the result is read at the right time and recorded with that time; and that the organisation receives a certificate it can retrieve later. Trust-based forms and photos provide none of these. Automated verification provides all four without a person watching.

Helping people get it right

Choose kits with clear instructions and, for children and older adults, saliva kits. Send instructions in the person's language. Ask people to test in good light, on a flat surface, with the phone propped up. Screen at a consistent time so results are comparable.

Where ScreenMe fits

ScreenMe guides the member through the test on their phone, verifies the procedure and identity automatically, and issues a certificate for each completed screening. Coordinators see who is verified; nobody watches anyone.