People with learning disabilities are still dying 25 years earlier than the rest of the population, a report has said.
The Learning Disabilities Mortality Review (LeDeR) calls for urgent action to prevent more avoidable deaths.
A quarter of learning disability deaths were caused by Covid in 2020, compared to 13% of other deaths.
NHS England said improving the health of people with a learning disability was a priority.
The LeDeR was established in 2015 to try to understand why so many people with learning disabilities were dying from avoidable causes, and to try and improve their access to healthcare.
The latest report compares data from the deaths of 9,110 people with learning disabilities who died over the past three years.
It found that while there had been some small improvements - life expectancy had increased by one year - people were still experiencing huge inequalities.
Pandemic highlighted disparity
In 2020, 24% of learning disability deaths were caused by Covid-19 compared to just 13% of deaths in the general population.
The peak month for deaths from Covid-19 was April 2020, when 59% of all deaths were from the virus.
It was the leading cause of death in men over 35 and women over 20 with learning disabilities throughout the past year.
Reviewers found that poor testing provision, a lack of support from specialist services and difficulties using the NHS 111 service played a part in many of the deaths.
In nearly a third of 'do not attempt cardio-pulmonary resuscitation' (DNACPR) orders made in relation to people who had died from Covid-19, the correct procedure was not properly followed.
In some cases, the reason given for a 'do not resuscitate' order was because the person had a learning disability.
One example cited in the report was because the person was "wheelchair-bound, needs to be hoisted, care home resident, learning disability."
They also found many examples of poor care - in 42% of the deaths in 2020, reviewers felt that the person's care had not met good practice standards.
'Son denied use of ventilator'
Steven Baskin's family feared that he could have become one of those statistics. The 43-year-old, who has Down's Syndrome, was treated in hospital for Covid-19 at the beginning of the outbreak, in March 2020.
His father, John, was told that his son would not be given access to a ventilator should he need one, because of his "underlying health conditions".
He said: "I received a call from a doctor who told me that a decision had been taken - should Steven require the use of a ventilator, then this would be denied.
"I was exercising in the park at the time of the call and had to find a bench to sit down - I was really taken aback."
He discussed Steven's condition with other senior doctors who intervened, and the decision not to give him a ventilator was reversed.
He said: "Steven had undergone treatment which affected his immune system, but other than this, he was perfectly healthy, and his treatment was going well."
Steven recovered from Covid-19, but his family felt they had had to fight to get him the access to healthcare they felt he needed.
'Not enough progress'
Report author Pauline Heslop, who is based at the University of Bristol, said: "This year, for the first time, we have been able to compare data based on the year of a person's death.
"There are some small signs of progress being made, but this is not sufficient, nor sufficiently well distributed across people with learning disabilities from different ethnic groups.
"Actions taken to date, while welcome, have clearly not been enough to make the progress we should expect to see."
Claire Murdoch, mental health director for NHS England, said: "Every year, people with a learning disability die sooner than they should and many from potentially avoidable conditions, such as constipation or aspiration pneumonia.
"Despite the pandemic, the NHS has ensured that three-quarters of people over the age of 14 with a learning disability have received their annual health check, two years ahead of the Long Term Plan target," she said.
"It is vital we use this report to make real and lasting change to help close the health inequality gap seen throughout society."