Stroke victims taken to Northampton General Hospital take six times longer to be seen by a specialist stroke team at evenings and weekends.
The figures come from a report into key stroke standards by the Royal College of Physicians.
It says NGH makes sure a stroke team sees the patient an average of 28 minutes after admission during weekday office hours.
But out-of-hours, when there are generally less staff, that average time increases to 195 minutes.
A spokeswoman for the Different Strokes charity’s Northampton Branch said: “The faster a stroke patient receives treatment, the better their chances are of surviving and reducing long-term disability.
“It is recognised that ‘time lost is brain lost’.
“We strongly feel that everyone should be given the same access to making the best recovery, no matter what the time of day or night.”
The figures come after a Hospital Guide 2011 report in November last year showed that, like many hospitals, patients admitted to NGH at the weekend were more likely to die than those who are admitted during the working week.
The report did not speculate on why this was the case, but NGH medical director, Dr Sonia Swart, said at the time that possible reasons could be fewer staff in most hospitals on weekends or that only the most sick people go to hospital on Saturdays and Sundays.
She also pointed out that, on a limited budget, it was almost impossible to fully staff a hospital seven days a week as people needed days off.
Although NGH’s October board meeting heard the imbalance in weekend death rates was getting better, particularly with regard to strokes, the hospital said this week it was still tackling out-of-hours staff shortages on stroke teams.
A spokesman for NGH said: “The figures should not be taken on their own but in the context of the whole service. NGH is seeing around 800 stroke patients per year. The hospital is already the top performing trust in the region for stroke team access in ‘working hours’ and the standards are continually improving across the board.
“There is 24-hour senior consultant cover. We are appointing more specialist stroke nurses in order to improve the access to the stroke team ‘out of hours’.
“This is part of our overall plan to increase the number of patients who can receive the most effective treatment for stroke.”