Effect of removing the 4-hour access standard in the ED: a retrospective observational study

Time-based targets are used to improve patient flow and quality of care within EDs. While previous research often highlighted the benefits of these targets, some studies found negative consequences of their implementation. We study the consequences of removing the 4-hour access standard.

We conducted a before and after, retrospective, observational study using anonymised, routinely collected, patient-level data from a single English NHS ED between April 2018 and December 2019. The primary outcomes of interest were the proportion of admitted patients, that is, the admission rate, the length of stay in the ED and ambulance handover times. We used interrupted time series models to study and estimate the impact of removing the 4-hour access standard.

A total of 169 916 attendances were included in the analysis. The interrupted time series models for the average daily admission rate indicate a drop from an estimated 35% to an estimated 31% (95% CI -4.1 to -3.9). This drop is only statistically significant for Majors (Ambulant) patients (from an estimated 38.3% to an estimated 31.4%) and, particularly, for short-stay admissions (from an estimated 18.1% to an estimated 12.8%). The models also show an increase in the average daily length of stay for admitted patients from an estimated 316 min to an estimated 387 min (95% CI 33.5 to 108.9), and an increase in the average daily length of stay for discharged patients from an estimated 222 min to an estimated 262 min (95% CI 6.9 to 40.4).

Lifting the 4-hour access standard reporting was associated with a drop in short-stay admissions to the hospital. However, it was also associated with an increase in the average length of stay in the ED. Our study also suggests that the removal of the 4-hour standard does not impact all patients equally. While certain patient groups such as those Majors (Ambulant) patients with less severe issues might have benefited from the removal of the 4-hour access standard by avoiding short-stay hospital admissions, the average length of stay in the ED seemed to have increased across all groups, particularly for older and admitted patients.