The comments by the Liberal Democrats followed the ONS analysis published on 17 January.
Liberal Democrat health and social care spokesperson Helen Morgan said: ‘It is sickening to think that thousands of deaths could have been avoided every year.
‘The new Government has so far shown a shocking lack of action in rescuing emergency care. They failed to prepare for this winter crisis and patients are paying the price.
‘Instead of putting forward a plan to winter proof the NHS, as the Liberal Democrats have been saying for months, ministers sat on their hands and let this situation develop.'
The ONS found 1.3% of people who attended A&E in England between 21 March 2021 and 30 April 2022 and did not die in hospital died within 30 days of leaving to return home or be admitted to inpatient care.
The adjusted risk of post-discharge death increased with total time spent in A&E after approximately two hours for patients requiring non-immediate care.
Compared with patients requiring non-immediate care who spent two hours in A&E, the odds of post-discharge death were: 1.1 times higher for those who spent three hours in A&E; 1.6 times higher for those who spent six hours in A&E; 1.9 times higher for those who spent nine hours in A&E; and 2.1 times higher for those who spent 12 hours in A&E.
The relative difference in the risk of post-discharge death after 12 hours in A&E compared with two hours in A&E was greatest for: younger patients (for example, the odds at 12 hours were 4.6 times higher than at two hours for patients aged 20 years), those in London (2.7 times higher), those who attended A&E for reasons to do with their eyes (7.9 times higher), and those who were not admitted to hospital for inpatient care after visiting A&E (2.8 times higher).
Professor Julian Redhead, NHS national clinical director for urgent and emergency care, said: ‘We know there is a real impact when patients wait too long in A&E.
‘This is a result of pressure across health and social care, including record A&E and GP attendances, challenges discharging patients from hospital and wards routinely operating at close to 100% capacity.
‘In response we have rolled out a number of services including virtual wards so patients can be supported from the comfort of their home, same day emergency care centres so patients arriving at A&E are seen quicker and discharged on the same day - while latest data shows the NHS has more beds opened than this time last year.
‘However more needs to be done to support patients and hard-working NHS staff, and we will work with Government to develop further plans to improve urgent and emergency care, including shifting more care to community settings as part of the 10-Year Health Plan.'
A Department of Health and Social Care spokesperson said: ‘The situation in our A&E departments is clearly unacceptable.
‘This Government has acted decisively to protect A&E by ending the resident doctors strikes, launching the new RSV vaccine, delivering 28m vaccinations for flu, Covid and RSV and securing an extra £26 billion in NHS funding.
‘Through our Plan for Change this government is making the investment and fundamental reform needed to ease pressure on urgent care and end the cycle of winter crises.'
