A record number of patients have been waiting a year or more for routine treatment at the Princess Royal and at the Royal Sussex County Hospital in Brighton, according to figures from the Nuffield Trust.
Both hospitals are operated by the Brighton and Sussex University Hospitals NHS Trust.
NHS rules state that patients referred for non-urgent consultant-led elective care should start treatment within 18 weeks.
But NHS statistics show 4,356 patients listed for elective operations or treatment at the Haywards Heath and Brighton hospitals at the end of February had been waiting for at least a year - compared with just 41 the previous year.
They also show that, overall, 38,567 people were waiting to start hospital treatment at both hospitals at the end of February – an increase of 187 on February 2020.
Trust chief operating officer Ben Stevens said: “The pandemic has led to higher waiting times across the country.
“We understand long waits are distressing for patients and have been prioritising those with the most urgent clinical needs first.
“We are in the process of restoring the elective programme by maximising the use of the available capacity within our hospitals and by working with independent sector providers where appropriate.”
The Nuffield Trust says the record size of the NHS waiting list across England shows the health service has been set back years by the coronavirus pandemic and now faces a ‘major backlog’.
And, it said, the strain of the backlog on patients should not be underestimated, but added it is no surprise given the intense pressure of Covid-19 hospitalisations.