A total of 4,017 new patients signed up in the month to 1 November 2019, figures from NHS Digital show, taking the service's total patient list to 68,569.
The surge in new registrations over the past month marks the fastest one-month rise in patient numbers for GP at Hand in more than a year and a half, analysis by GPonline reveals.
In the two years since the video consultation service was given the green light to begin registering patients outside the south-west London area where its host practice is based, it has added more than 63,500 patients to its list.
Nine out of 10 patients who have signed up since November 2017 are aged between 20 and 39 years old - and this group make up 86% of the practice's total patient list - leading to accusations of cherry picking, which GP at Hand denies.
The growth of the service, run by private company Babylon, has been exponential since it began offering a primarily video consultation-based model from a small practice in Fulham, in London.
In April 2017, the Lillie Road practice had just 2,500 patients, a figure that had increased to 4,970 by November 2017, when it opened its doors to out-of-area patients. From this point registrations have risen rapidly, backed by advertising campaigns on London public transport and online, and with repeated endorsements from health and social care secretary Matt Hancock - who is himself registered with the service.
The service could be set for even faster growth in the near future if a 2,600-patient cap on registrations in the Birmingham area is lifted, and if it presses ahead with plans to expand into Manchester from early 2020.
Changes to rules around digital first providers could force the break-up of its patient list, too - with a requirement set to take effect from April 2020 for providers to set up physical premises under a new APMS contract in any CCG area from which they register more than 1,000 patients. GP at Hand has drawn in more than 1,000 patients from more than 15 different CCG areas.
The service has proven controversial because GPs fear it is undermining existing general practice services, with GPs in east London set to lead a protest on 21 November. Doctors who belong to Britain and Ireland's largest union, Unite, say GP at Hand is cherry picking young, wealthy patients.
Chair of Doctors in Unite and Tower Hamlets GP Dr Jackie Applebee said: 'We object to GP at Hand on two main grounds – one that it is draining resources from the NHS to the private sector; and, secondly, it is reducing the resources that GPs have for their more chronically ill and elderly patients.
'The accelerating rate of the privatisation of the NHS, of which GP at Hand is a prime example, is creating a two-tier health service which undermines the fundamental ethos of the NHS when it was founded in 1948.'
The BMA has called on the government and NHS England to stop the service's registration of out-of-area patients because of its impact on other GP providers.
A Babylon spokesperson denied the service cherry picked healthy patients. He said: 'We welcome every patient who lives or works in the area, regardless of their health or age or anything else.
'Patients have chosen us because we offer GP appointments, day or night, every day of the year through people’s phones and computers so if they can’t travel, or don’t want to travel they can still speak to a doctor and show them what’s wrong. Anyone who needs to have an in-person appointment can use one of our clinics.'