Table 3 Process re-design interventions and intervention characteristics

Guidelines and Protocols

Process redesign also refers to changes to existing or the introduction of evidence-based clinical practice guidelines for specific conditions [31], protocols (pathology: [31]; treatment: [25]; medication: [34, 42], mandating the redundant reading of emergency CT scans [35].

Patient Assignment and Referral Processes

Patient assignment processes [31], and referral processes [4, 31, 36]. Case management involves the identification of appropriate providers and services for individual patients based on a continuous, integrated medical and psychosocial model of care [37, 38].

Organisational Processes

Communication and consultation intervention between radiologists and ED physicians to reduce patient call backs to the ED [35], administrative interventions (e.g., outsourcing environmental services, [25]), the addition of administrative, clinical and ancillary personnel [39], logistical changes in radiology and laboratory [39], rearranging bed zones [39], performance targets (e.g., the 4 h rule, disposition [19, 40];.

Nurse-Initiated Care Processes

Nurse-initiated care processes consist of various interventions relating to nursing activities [8]. Reviews examined interventions relating to nurse-initiated care processes in ED including medication [41, 42], x-ray [8, 17, 21, 43, 44], protocols [19], and diagnostic tests [44].

Clinical Decision Supports

Clinical decision supports refers to the use of a validated clinical decision rule to assess the pre-test probability of the diagnosis [45, 46] or tool to assess the need for diagnostic investigations [47]. For example, tools to assess the need for imaging in adult patients include the National X-radiography Utilization Study (NEXUS) criteria, and the Canadian C-Spine Rule (CCR [47];).

Lean Management/ Thinking

Lean management/ thinking is a suite of concepts, methods and tools developed by Toyota Motor Corporation [48,49,50]. Lean processes are designed to improve productive capacity and reduce waste [48,49,50]. Three reviews examined Lean interventions in ED [48,49,50]. Lean has been applied in a number of ways. For example, designing a detailed map of the process (Value Stream Map – VSM) to identify waste and bottlenecks [48], streaming patients according to severity, dedicating different ED spaces for different types of patients [48] with dedicated nurse and physician for the different areas [48]. Other lean interventions included computer systems implantation, changes in roles and responsibilities, flow managers and screening nurses [48]. Kaizen events moderated by lean consultants or lean specialist (VSM, leadership involvement, boot camp, reallocation of staff, commitment of the department chairperson, communication board, periodic electronic communication [48];). Process changes such as new processes and related operating procedures including eliminating outdated policies, fast-track process for low complexity patients. System changes include data collection and monitoring (e.g., weekly review, quality improvement measurements taken and shared with staff), education/ training (orientation to the new process, posting process map in public areas), tools/ technology (standardised forms, checklists), communication and teamwork (communication tools, team assessment of patient history), staffing reassignment/ new roles/ responsibilities (reassignment to match peak patient volume or arrival rates, dedicated ECG and laboratory technician in ED, reassignment/ reorganisation of space (e.g., space reallocated for rapid assessment and holding patients, designated physician examination rooms), other changes (stocking done as needed, improved signage, celebrating goal achievements) [49]. Lean intervention team composition included, hospital management team or the head of ED, physicians, nurses, staffs and external counsellors, as well as external consultants (experts in lean [50];.