Older people and the very sick will be visited within two hours by a “rapid response team” of health and care staff under new NHS plans to relieve the strain on overcrowded hospitals.

The teams will include nurses, physiotherapists, occupational therapists, social workers and social care staff working for NHS trusts and local councils in England.

The “urgent community response” teams will operate 365 days a year. They will help older people and those with complex care needs whose health has suddenly deteriorated – through a fall, infection or exacerbation of an illness – try to avoid ending up in hospital.

Patient and medical groups have welcomed the teams, which are a key element of the NHS’s plan to provide increasing amounts of care in people’s homes and care homes.

“A guaranteed response within two hours is exactly the kind of security people need and want to give them the confidence that they will get timely support at home,” said Caroline Abrahams, the charity director at Age UK.

“At the moment people understandably feel there is no option but to call an ambulance or head to A&E, something that is both distressing for older people and often the wrong place to help them recover as quickly as possible.”

The NHS and councils in seven areas of England will start putting the teams together and hiring staff from April, with at least three starting to offer the service before next winter brings extra demand for NHS care. The seven areas include Cornwall, Cheshire and Merseyside and south-east London.

However, NHS chiefs have promised that every part of the country will have a rapid response team in place by April 2023, paid for by the extra £4.5bn they are putting into out-of-hospital care services.

“The NHS working hand in glove in the community with council-funded social care services can be the difference between an older person or someone with long-term health needs spending a week or a month on a ward, or getting the right help early so they don’t need to go to hospital in the first place,” said Sir Simon Stevens, NHS England’s chief executive.

Age UK estimates that there are almost 500,000 older people in England who are living at home and have multiple health and care needs.

Potentially heavy demand for the new service prompted concern that NHS trusts may not have enough staff to offer everyone who needs it urgent assistance within two hours. The NHS has more than 40,000 vacancies for nurses.

“This announcement comes on the day that new figures show yet more nurses have been lost from our local community services in recent years,” said Dame Donna Kinnair, the chief executive of the Royal College of Nursing.

“The evidence shows it is district nurses and health visitors who provide high-quality holistic care in people’s homes. There can be no substitute for having enough nurses in communities, social care and hospitals too.”

Figures published by NHS Digital show that the number of nurses working in community services has fallen over the past decade from 67,316 in September 2009 to 62,898 last October – a drop of 6.6%.