Thread by @deeksj

How well will these 15-minute rapid tests Boris mentioned work? (quick answer – we don’t know)

The Innova test was mentioned this week in Telegraph.
telegraph.co.uk/news/2020/10/1…

and I presume was on Boris’s list of the tests last night.

We are updating our Cochrane review and have been through our searches. There are no pre-prints or published studies of this test.

There are 2 studies – 1 from the company Instructions for Use (IFU) and 1 from PHE Porton Down.

Test is made by Xiamen Biotime Biotech in China.

Quick Critical appraisal of PHE Porton Down study:
1)Is the study relevant? Can’t tell.
2)What do the results mean? Can’t tell.
3)Should we believe the results? Can’t tell.
(please give us the full report!!!)

The company study is reported in Instructions for Use, and available in presentation download - more information provided from a manufacturer than often - thank you!

triedandtested.tech

But first note the “Intended Use” statement in the IFU. This states what the test can be marketed for – test is for use in symptoms in the first 5 days of illness. Certainly not intended for use in people without symptoms.

And states not for home use – of course this could change but currently appears not to have MHRA approval for home use – correct me if I am wrong. Unclear how it can be rolled out for widespread use this week - home use approval takes work, no Covid-19 test has it yet.

Here is the description of the study – accompanying powerpoint helps explain. Cohort of 295 with RT-PCR testing of nasal swabs with confirmed pneumonia in first 5 days of symptoms , 75 were RT-PCR+, 220 RT-PCR-. Second stage of 25+25 relates to testing with pharyngeal swabs.

Here is the 2x2 table. Sensitivity 96% (89-99%); Specificity 100% (98.3-100%)

There are important limitations to the product mentioned in the manufacturer’s IFU

Summary– test appeared to perform well in company study limited to people with pneumonia in first few days of symptoms (so severe and likely to have high viral load – easier to detect). No evaluation of infectiousness– only infection. Must be used by a health care professional.

No data presented on accuracy in asymptomatics, or in people with less severe symptoms, or at other time points. Only nasal swabs tested, not saliva.

My view: current evidence seems very inadequate to consider implementing this test.