Table 4.

Summary of simulation results

Study name	Conclusions	Conclusions detail	Reported the changes implemented?	Result implementation	Barriers
Anagnostou et al 21	None	None	No	NA	None
Au-Yeung et al 22	Supported the changes considered	Prioritisation of treatment for patient with minor problems over major problems could lead to improved outcome	No	NA	Simplified assumptions
Baboolal et al 23	Supported the changes considered	A change in staffing levels could lead to substantial cost savings and reduce the 4-hour breaches	No	NA	None
Bowers et al 24	None	None	No	NA	Model runtime; high expectancy
Brailsford et al 10	Opposed the changes considered	Streaming of patients by triage category was not an efficient use of clinical resources	No	NA	None
Coats and Michalis25	Supported the changes considered	Shift pattern that best matches patient arrivals would give shorter waiting times	No	NA	Simplified model structure and assumptions; poor data quality
Codrington-Virtue et al 26	None	None	No	NA	None
Codrington-Virtue et al 27	None	None	No	NA	None
Coughlan et al 28	Proposed differential changes	Adding an emergency nurse practitioner would not reduce the waiting times. Resource reallocation would improve throughput times	No	NA	Generalisability
Davies29	Supported the changes considered	The separation of see and treat would be beneficial	No	NA	Poor data quality
Eatock et al 11	None	None	No	NA	System complexity; model runtime
Fletcher et al 12	Proposed differential changes	Deflecting demand away from A&E would lead to improvement around waiting for beds, specialists and assessment processes	Yes	Unknown as other interventions were introduced in parallel	Poor data quality; poor stakeholder engagement
Günal and Pidd13	None	None	No	NA	Explaining the causes of change in performance
Günal and Pidd30	Proposed differential changes	More senior doctors, less X-ray requisitions and more cubicles would reduce waiting times	No	NA	Modelling multitasking behaviour of staff
Hay et al 31	None	None	No	NA	System complexity
Komashie and Mousavi32	Proposed differential changes	Adding a nurse or doctor to minors would reduce the waiting times by 28%. Increasing the cubicles/beds would make smaller change	No	NA	None
Lane et al 33	Proposed differential changes	Changing bed numbers led to no noticeable change in waiting times but a substantial difference to elective cancellations	No	NA	Short timescale; simplified assumptions
Lattimer et al 14	Proposed differential changes	System would not be able to cope with increasing demand from scenario 1*, but scenarios 2†, 3‡ and 4§ could improve this	No	NA	Simplified model structure; system complexity; generalisability
Maull et al 34	Supported the changes considered	See and treat reduced the 4-hour breaches from 13.2% to 3.4%	Yes	Marked reduction in no. of breaches from 13.2% to 1.4%. No. of patients waiting less than 1 hour increased from 12% to 23%. No. of patients with major problems waiting between 3 and 4 hours increased	Poor data availability and quality; system complexity
Meng and Spedding35	Proposed differential changes	Reduced times to see a consultant would reduce the waiting times. Access to 24-hour X-ray would reduce the waiting times too	No	NA	Simplified assumptions
Mould et al 36	Supported the changes considered	A new staff roster would reduce the waiting times	Yes	Mean time for minor problems dropped from 100 to 94 min, for major problems it dropped from 200 to 195 min. Mean time for minor problems fell by 16 min after adjusting other factors	Poor data quality; limited analytical skills; impact of simulation

*Five-year model run assuming 4% year-on-year growth in emergency admissions and 3% year-on-year growth in general practitioner (GP) referral for planned admissions.

†Impact of increase in demand for front door services.

‡Reducing emergency admissions of patients with respiratory or coronary problems, ill-defined conditions and over 65 years.

§Effects of earlier discharge of patients admitted as emergencies and subsequently discharged to nursing or residential homes.

A&E, accident & emergency department; NA, not applicable.