Waiting for longer than five hours in emergency care before admission to hospital is linked to a heightened risk of death from any cause within the next 30 days, according to a study published in the Emergency Medicine Journal.

The researchers say this can be measured and represented as a ‘number needed to harm metric’, of 1 extra death for every 82 patients delayed for 6-8 hours.

Rising patient demand has meant people are waiting longer in A&E compared to previous years

The 4-hour waiting time target before hospital discharge, admission, or transfer was introduced in 2004 in England, but recently performance against this target has steadily declined amid rising patient demand.

The researchers wanted to quantify the increased risk of harm and death as a result of these delays, so they drew on Hospital Episode Statistics and Office of National Statistics data for England, covering every patient admitted to hospital from each major (type 1) emergency department in England between April 2016 and March 2018.

They compared recorded deaths from any cause within 30 days of admission with those that would be expected, allowing for factors such as sex, age, deprivation level, concurrent conditions, time of the day and month, previous attendances/emergency admissions, and crowding in the emergency department at the time.

The study’s results are based on evidence from five million patients

Out of the 26,738,514 people attended an emergency department in England, more than five million were admitted to hospital. In total, 433,962 people died within 30 days during the study period, meaning the overall unadjusted 30-day death rate was just under 9%.

The average wait in the emergency department was just under 5 hours, and the breach rate of the of the 4-hour waiting time target averaged around 38%. A statistically significant linear increase in the death rate was identified for waits longer than 5 hours in the emergency department.

After accounting for potentially influential risk factors, the death rate was 8% higher than expected among those patients waiting between 6-8 hours before admission to hospital, and 10% higher than expected for those waiting 8-12 hours, compared with patients moving on within 6 hours.

Healthcare policy makers “should continue to mandate timely admission” from emergency care in order to protect patients

Because the study is observational, it can’t establish a cause. However, the researchers say there are “a number of clinically plausible reasons to accept there is a temporal association between delayed admission to a hospital inpatient bed and poorer patient outcomes.”

These include:

  • Long stays in the emergency department are associated with exit block and crowding, which can delay access to vital treatments.
  • Because exit block is usually related to bed occupancy levels, which are highest in the late afternoon and usually lower around midnight, a disproportionate number of delayed patients are therefore likely to be moved to a ward during the night when staffing levels are lowest.
  • Long stays are also associated with an increase in subsequent hospital length of stay, especially for older patients, which in turn, increases the risk of hospital-acquired infection and physiological and psychological deconditioning.

The study’s authors therefore conclude that “healthcare policy makers should continue to mandate timely admission from the [emergency department] in order to protect patients from hospital-associated harm.”