ASX-listed digital health firm ResApp Health has announced that its pilot clinical trial for a smartphone-based COVID-19 screening test has achieved positive results. 

The new diagnostic app, which uses machine learning to analyse the sound of a patient's cough, was reported to correctly detect COVID-19 in 92% of participants with the infection during the trial. With a 92% sensitivity, it exceeds real-world measured sensitivity of rapid antigen tests, ResApp claims. 

FINDINGS

The clinical trial in the United States and India involved 741 patients with around 60% of them COVID-19 positive. 

Based on preliminary results, the app was also found to be "outstanding," having attained an area under the curve of 0.9, when measured for how well it distinguishes between two diagnostic groups. It also obtained 80% specificity in identifying patients who tested negative for COVID-19. 

To ensure that its algorithms are detecting COVID-19, it was checked against the Breathe Easy dataset, which includes data from over 1,000 patients with various non-COVID-19 respiratory conditions. 

ResApp also shared that the app showed "consistent performance" over two periods, one when Delta was the major variant and the other when Omicron was the dominant variant.

The company further noted that the app demonstrated "lower" performance in asymptomatic patients, although it only recruited a small number of them.

ResApp said it will publish the results of its clinical trial in a peer-reviewed journal "in the coming weeks".

WHY IT MATTERS

The World Health Organization has warned that the global pandemic is far from over and that health systems must be prepared to face more dangerous variants.

ResApp aims to initially bring its latest screening solution in places where frequent COVID-19 testing is needed, such as workplaces, hospitals, schools, travel areas, sports venues, entertainment hubs, and aged care centres. With its smartphone-based test, rapid antigen or PCR tests would be required less to confirm COVID-19 in these settings given its high sensitivity and specificity.

ResApp CEO Tony Keating said they are now reaching out to regulators across markets and have already engaged with global health tech companies to roll out its app-based screening test. 

Moreover, the COVID-19 screening app also has the ability to "improve security and reporting of results" using biometric identification like facial recognition.

MARKET SNAPSHOT

Other tech developers have built algorithms to detect COVID-19 by analysing patients' cough sounds. In 2020, researchers from the Massachusetts Institute of Technology in the US developed an AI tool to diagnose COVID-19 that was trained using over 70,000 audio recordings, including those from infected patients. In October last year, Andhra Medical College in India tried out Salcit Technologies' Swaasa AI platform, which conducts an audiometric analysis of cough sounds, along with temperature, oxygen saturation, symptoms, of suspected COVID-19 patients.

Meanwhile, Breathonix, a spin-off company from the National University of Singapore, has developed a breath test that can rapidly detect COVID-19 within a minute. 

ON THE RECORD

"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," Catherine Bennett, a professor and the chair of Epidemiology at Deakin University, commented.