Research by the Nuffield Trust, carried out through the QualityWatch programme and funded by the Health Foundation, found 43% of patients aged over 80 waited more than 12 hours between arriving at A&E and being admitted to a ward, compared to 19% of those aged between 21 and 30.
The think tank said long waits have become a regular feature of emergency care since the Covid-19 pandemic.
In February 2026, more than 72,000 patients waited over 12 hours for a bed, accounting for a third of all admissions.
Researchers said older patients were more likely to face long delays even when only looking at people who were eventually admitted to hospital.
What's more, the report found individuals with breathing problems, neurological conditions and gastrointestinal illnesses were more likely to be affected by delays, with over a third waiting more than 12 hours.
Alongside the findings, the report looked at the increasing use of corridor care - where patients are treated in temporary spaces while waiting for a hospital bed.
NHS England has recently introduced a definition of corridor care and begun publishing national data.
The first figures show there were almost 73,000 cases in June, accounting for around 5% of A&E attendances, with numbers highest at weekends.
Although researchers welcomed the move, they said recording corridor care alone wouldn't help slash long waits. The report outlined a shortage of NHS beds and limited access to health and social care outside of hospital were also adding to pressures.
Against this backdrop, the think tank is calling on the government to prioritise social care reforms and more investment in healthcare.
Nuffield Trust Deputy Director of Research, Sarah Scobie, said: 'It's absolutely shocking that two-fifths of the most elderly patients going into A&E are stuck waiting for over 12 hours, often in unsafe conditions, when they are already extremely unwell and vulnerable.
'Behind every case of corridor care counted in the new data is a person going through a frightening and traumatic experience. The fact that we even need a proper definition and data for corridor care in the NHS shows just how far A&E performance has spiralled out of control, with very long waits now the norm.'
'The evidence is clear that we need improvements in how patients flow through hospitals after A&E,' she added. 'Better access to health and social care services outside hospital - both before and after an admission is needed – is also needed to bring about a sustained reduction in long A&E waiting times.'
