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 opening on the cassette, 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.
Common procedural errors
Swabbing too briefly or not deep enough. Not waiting the time the kit specifies before reading the result, or reading it after the kit's time limit has passed. 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.
The role of supervision in testing programmes
Every health authority 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.
Verification options when live supervision is not used
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 each screening is tied to the invited participant; that the result is recorded with the time the test was taken; and that the organisation receives a certificate it can retrieve later. Trust-based forms and photos provide none of these. Verified at-home testing provides all four without a person watching.
Supporting correct test procedures
Nasal swab kits with clear instructions are recommended. Instructions should be provided in the person's language. People should test in good light, on a flat surface, with the phone propped up. Screening at a consistent time makes results comparable.
Role of screenme.science in the verification process
screenme.science guides the participant through the test on their phone, checks the required steps of the procedure and ties the screening to the invited participant, and issues a record for each completed screening. Coordinators see who is verified, and no live observation takes place.