ResApp Health (ASX:RAP), a digital health company developing smartphone applications for the diagnosis and management of respiratory disease, has announced top-line data from its multi-site, double blind, prospective clinical study to investigate ResAppDx for the diagnosis of respiratory disease in infants and children using cough sounds.
The predefined study endpoints were based on achieving greater than 75 per cent for positive per cent agreement (PPA) and negative per cent agreement (NPA) for the diagnosis of pneumonia, croup, bronchiolitis, asthma/reactive airways disease (RAD), lower respiratory tract disease (LRTD) and upper respiratory tract infection (URTI).
In the final data review, prior to the un-blinding of the study data, ResApp identified at least two issues with the clinical data.
Contrary to instructions and training, a high number of patients were treated before clinical research staff recorded their cough sounds. A high number of recordings were also found to contain a second person’s cough sounds or an unacceptable amount of background noise and interference. These issues are known to affect cough sound analysis and their presence has skewed these preliminary results.
A preliminary analysis indicates that the study is unlikely to meet its predefined endpoints for diagnosis of childhood respiratory disease with the lower bound of the 95 per cent confidence interval of both PPA and NPA with clinical diagnosis being below 75 per cent of all diseases.
The most promising result was for bronchiolitis, which achieved an 80 per cent PPA and 95 per cent NPA with clinical diagnosis, although the company said due to the reduced number of bronchiolitis patients (caused by removing recordings with obvious issues) this result does not meet the predefined study endpoint.
Following the final review, the company said it may proceed with an FDA submission for bronchiolitis.
“These are not the results that we expected given our experience in Australia. It is obvious that a large number of tests have been affected by procedural anomalies and we now need to go through each case one by one to fully understand the results. I am confident that we can add another layer of detail to the next set of study protocols to deliver robust results and that we have adequate funding to complete a second US paediatric pivotal clinical study this US winter as well as continue and complete our adult program, including our US adult pivotal study which is also set to begin this US winter,” said Tony Keating, CEO and Managing Director of ResApp Health.
“The results from SMARTCOUGH-C did not meet our expectations based on previous studies, including our limited prospective testing done in Australia. The SMARTCOUGH-C data provides a valuable insight into the recruited US population and into US diagnosis practices,” said Dr Udantha Abeyratne, Chief Scientist of ResApp Health and lead inventor of the ResApp algorithms.
“We can use this study data to retrain the algorithms to capture such differences and significantly boost the robustness of our algorithms as well as refine study procedures at the participating hospitals to deliver results which are more representative of the algorithms’ capabilities.”