A newly launched rehabilitation app will help COVID-19 patients in Britain deal with the long-term symptoms of the disease.

Doctors around the world are increasingly warning that for many patients, clearing infection of the novel coronavirus is only the beginning of recovery. Persisting symptoms including fatigue, weakness, shortness of breath and anxiety may continue for months.

Some patients in the United Kingdom have reported feeling abandoned after discharge from hospitals, where they are discouraged from participating in too many on-site appointments in order to stop further spread of the virus.

The app's developers hope to address this problem by providing a rehabilitation tool designed by health experts that can be delivered completely remotely.

"The proportion of people needing further help is really high," said Paul Pfeffer, a respiratory physician at St Bartholomew's Hospital who contributed to the app. "We're finding that half of the patients we discharge from hospital are still experiencing significant symptoms after three months."

The app is developed by Living With, a UK-based digital health company, and physiotherapists, psychologists, dieticians, and respiratory doctors from University College London and several UK hospitals all collaborated on the digital tool.

Elizabeth Murray, a professor of healthcare engineering at UCL who led the project, said that there are not enough staff and resources in the UK to reach everyone recovering from COVID-19 by using traditional models of care, such as face-to-face appointments.

"This tool allows us to provide high-quality treatment to large numbers of patients simultaneously," Murray said. "The uniqueness of this tool is that the whole treatment program is delivered digitally. This benefits patients unable to come into the clinic, but it also allows us to help a far greater number of people in a cost-effective and time-effective way."

At the beginning of the pandemic, COVID-19 was primarily referred to as a respiratory disease. It has become increasingly apparent that the virus can damage many tissues and organs beyond the lungs and heart, leading to complex and often long-term symptoms.

The app aims to primarily target three symptoms commonly reported by those in the mid to late stages of recovery, namely fatigue, breathing problems, and anxiety.

Stuart Linke, a psychologist at UCL, said that the mental health component of the app is as important as the physical.

"We are finding that the symptoms are often interrelated — for instance, if you're feeling anxious you may be less likely to eat well, which may lead to further tiredness, which further impacts your mood and so on," Linke said. "A core feature of the recovery tool is cognitive behavioral therapy delivered by psychologists to help with anxiety."

Chris Robson, chief executive of Living With, said his company hopes to augment the app with a larger "artificial intelligence-driven intervention that will be rolled out more widely across the UK".