LONDON (AP) — Alcohol-related deaths in England and Wales jumped by a fifth last year to reach their highest level in two decades, new government figures showed Thursday.

The Office for National Statistics said there were 7,423 deaths attributed to alcohol misuse in 2020, a 19.6% increase from the year before. It said the majority were due to chronic conditions, such as alcohol-related liver disease.

The rise began in March 2020, when the U.K. began its first coronavirus lockdown, and the rates for the rest of the year remained significantly higher than in previous years.

The provisional data showed that alcohol-specific deaths among men were 4.2 times higher in the poorest areas of Wales and England than in the most affluent areas.

The statistics office said complex factors contributed to the rise in deaths and that it may be some time before the causes are fully understood. It said, however, that it was clear high-risk drinkers increased their alcohol consumption during the pandemic.

Sadie Boniface, a visiting researcher at King’s College London who studies alcohol use, said the reasons behind the increase in alcohol-related mortality last year were likely to include more consumption among people who had been drinking “at dependent levels for some time.” Access to health care and fear of going to the hospital for treatment during the pandemic also likely played a role, she said.

“Last year, there was a reduction in emergency presentations and admissions across the board, and addiction treatment data also showed fewer new clients starting treatment last summer,” Boniface said.