-92% sensitivity for detecting COVID-19 with a new cough audio-based algorithm 

ResApp Health Limited (ASX:RAP) today announced positive results for a new 
novel cough audio-based COVID-19 screening test that only requires a 
smartphone. In an exploratory clinical trial of 741 patients (446 COVID-19 
positive) recruited in the United States and India, ResApp's screening test, 
which uses machine learning to analyse the sound of a patient's cough, was 
found to correctly detect COVID-19 in 92% of people with the infection.

ResApp will position this as a non-invasive, instant, smartphone only screening 
test to rule out COVID-19 and be used prior to a rapid antigen (RAT) or PCR 
test.

In the trial, the test achieved a sensitivity of 92% (better than real-world 
data on rapid antigen tests[i],[ii]) and a specificity of 80%. The combination 
of high sensitivity and 80% specificity results in 8 out of 10 people without 
COVID-19 being correctly screened as negative and not requiring a follow-on 
rapid antigen or PCR test.

The performance of the algorithm was obtained using K-fold cross-validation to 
provide an estimate of performance on unseen data. ResApp intends to submit the 
results for publication in a peer-reviewed journal in the coming weeks.

As a smartphone-based test, it's non-invasive, easy-to-use, and instant, the 
entire test and results takes less than 30 seconds. The test also has unlimited 
scalability, no supply chain or distribution issues and none of the 
environmental impacts of rapid antigen tests.

ResApp will target use in settings where frequent COVID-19 testing is required, 
such as employee, healthcare worker and student screening, travel, sports, 
entertainment, and aged care. 

Professor Catherine Bennett, Chair of Epidemiology at Deakin University, and a 
member of ResApp's COVID-19 Scientific Advisory Board said: "The scale of this 
pandemic and the likely evolution to an endemic disease means we need more 
scalable diagnostic tools that can balance our current over-reliance on rapid 
antigen and PCR tests. By rapidly ruling out COVID-19, ResApp's COVID-19 test 
would significantly reduce the number of rapid antigen and PCR tests required, 
while still maintaining the disease surveillance needed to manage the continued 
impact of COVID-19. The simplicity, ease of use and unlimited scalability of 
ResApp's test will be welcomed by public health officials around the world."

Tony Keating, CEO and Managing Director of ResApp added: "This non-invasive, 
smartphone test will offer a unique opportunity to provide a rule-out screening 
test for COVID-19 at scale across the world, delivering huge savings to 
government, insurers and the public as well as significantly reducing the 
environmental impact of rapid antigen and PCR tests. These results also build 
our confidence in the development of patient management and monitoring tools 
for COVID-19 and expanding our research into long-COVID."

[i] Dinnes J., et al. (2021). Rapid, point-of-care antigen and molecular-based 
tests for diagnosis of SARS-CoV-2 infection. Cochrane Database of Systematic 
Reviews. https://doi.org/10.1002/14651858.CD013705.pub2
 
[ii] Hayer J., Kasapic D. and Zemmrich, C. (2021). Real-world clinical 
performance of commercial SARS-CoV-2 rapid antigen tests in suspected COVID-19: 
A systematic meta-analysis of available data as of November 20, 2020. 
International Journal of Infectious Diseases, 108, 592-602. 
https://doi.org/10.1016/j.ijid.2021.05.029 
 

About ResApp Health Limited

ResApp Health Limited (ASX: RAP) is a leading digital health company developing 
smartphone applications for the diagnosis and management of respiratory disease 
with products that are CE Marked in Europe and TGA approved in Australia. For 
more information, visit www.resapphealth.com.au.

Source: ResApp Health