Jessica Watson Profile picture
GP, Academic Clinical Lecturer & mother of four. Interested in rational use of blood tests, trying to avoid overdiagnosis. Violinist, wild swimming and cycling.
Peter English #FBPE Profile picture 1 subscribed
Sep 8, 2020 9 tweets 3 min read
1/ #Covid19 antibody testing @bmjlatest article with @deeksj published today bmj.com/content/370/bm…
Great interactive infographic from @will_s_t
A summary
Thread👇 2/Possible reasons for antibody testing:
Diagnosis (esp late presentation / RT-PCR negative)
To answer the question ‘have I had it?’
Seroprevalence surveys
Research into immune response
*Interpretation of results depends on pre-test probability which varies between these groups*
May 30, 2020 9 tweets 3 min read
How can GPs help ensure #covid19 #antibody tests are used wisely? 100,000 (or is it 200,000?) tests a day is only useful if we get the right test, for the right patient and the right time. Thread 👇 GPs have been told to offer antibody testing to anyone having their blood taken who wants to know whether they have been infected with covid-19, even if there is ‘not a specific clinical indication’ pulsetoday.co.uk/news/gps-to-pr…
Apr 2, 2020 13 tweets 2 min read
So much in the media about #COVIDー19 testing, it seems important to correct some misconceptions. Thread👇 Two types of test:

Viral RNA tests - RT-PCR - swab tests - to detect current infection

Antibody test - serology - blood tests - to detect previous infection
Jun 18, 2019 7 tweets 4 min read
1/6 What is the usefulness of inflammatory markers such as CRP, ESR and PV in #primarycare? My #PhD findings may make you think carefully about doing these tests. A thread 👇bjgp.org/content/early/… 2/6 Inflammatory markers have an overall sensitivity of <50% so are not a useful 'rule out' test: