Database searches retrieved 15454 records. Following screening of titles and abstracts, 2393 studies met the inclusion criteria. From those, 624 acute care studies were assessed for eligibility, from which 319 were excluded, considering the clinical areas excluded for this review. A total of 305 acute care studies focusing on healthcare utilization and general surgery were considered for full-text screening. Two records were identified via hand-searching. Following the full-text screening, 152 were included and 155 studies were excluded (reasons for exclusion detailed in Fig. 1).
Studies characteristics
A total of 152 studies were included (Additional file 4), conveying information from 27 countries. The most frequent study design was the retrospective cohort (n = 141; 92.8%), followed by 5 prospective cohort studies (3.3%), 4 systematic reviews (2.6%), and 2 surveys (1.3%). Administrative data (n = 92; 56.8%) and clinical data (n = 49; 30.2%) were the most frequent data sources, followed by registries (n = 8), claims (n = 4), population-level data (n = 3), and surveys (n = 2). The most frequent countries reported on, excluding the literature reviews, were the United States of America (USA) (n = 39; 26.4%), Italy (n = 21; 14.2%), Canada (n = 12; 8.1%) and the United Kingdom (UK) (n = 10; 6.8%) (Table 1). The magnitude of the indicators in the year 2020, in each study, were compared to their magnitude in 2019 (n = 240; 36.9%), to the period immediately before the beginning of the pandemic (n = 162; 24.9%), or to the average in previous years, ranging from 2018 to 2019 (n = 111; 17.1%). Some studies compared the first half of the year 2021 to 2019 (n = 103; 15.8%) or the first half of the year 2021 to the previous years (n = 34; 5.2%).
Table 1
– OECD countries included in the analysis, excluding literature reviews (n = 148 studies)
Country | Number of studies included |
n | % |
United States of America | 39 | 26.4% |
Italy | 21 | 14.2% |
Canada | 12 | 8.1% |
United Kingdom | 10 | 6.8% |
Turkey | 9 | 6.1% |
Germany | 8 | 5.4% |
United Kingdom | 5 | 3.4% |
Israel | 5 | 3.4% |
Australia | 5 | 3.4% |
Japan | 4 | 2.7% |
France | 4 | 2.7% |
Ireland | 4 | 2.7% |
Spain | 3 | 2.0% |
Finland | 3 | 2.0% |
Switzerland | 3 | 2.0% |
Greece | 2 | 1.4% |
Scotland | 1 | 0.7% |
Austria | 1 | 0.7% |
Slovenia | 1 | 0.7% |
Croatia | 1 | 0.7% |
Korea | 1 | 0.7% |
Netherlands | 1 | 0.7% |
Belgium | 1 | 0.7% |
New Zealand | 1 | 0.7% |
Hungary | 1 | 0.7% |
Norway | 1 | 0.7% |
Portugal | 1 | 0.7% |
Acute care indicators
A total of 2953 indicators related to acute care were collected: 2354 indicators from 124 studies focusing on general emergent/urgent healthcare and 301 indicators from 28 studies related to acute general surgery (Table 2).
Table 2
– Groups of performance indicators across the acute care pathway (n = 2953 indicators)
| Number of indicators a) | Number of studies | |
| n | % | n | |
General emergent / urgent healthcare |
1. Pre-hospital services | | 13.6% | |
1.1. Volume of patients contacting Emergency Medical Services | 225 | | 20 |
1.2. Volume of bystander cardiopulmonary resuscitation | 26 | | 10 |
1.3. Proportion of patients with out-of-hospital cardiac arrest witnessed by bystanders | 12 | | 9 |
1.4. Pre-hospital treatment times: from call to care provided | 59 | | 12 |
1.5. Survival rate of patients with out-of-hospital cardiac arrest | 81 | | 14 |
2. Admission to the Emergency Department | | 46.2% | |
2.1. Volume of Emergency Department visits | 1066 | | 87 |
2.2. Arrival mode to the Emergency Department | 78 | | 22 |
2.3. Level of urgency by triage system | 186 | | 34 |
2.4. Clinical severity at admission | 26 | | 8 |
2.5. Duration of symptoms prior to presentation b | 9 | | 5 |
3. Diagnosis | | 5.5% | |
3.1. Volume of diagnostic procedures | 131 | | 16 |
3.2. Rate of positive findings after diagnostic testing | 32 | | 4 |
4. Treatment | | 4.9% | |
4.1. Volume of therapeutic interventions | 106 | | 18 |
4.2 Operational times | 17 | | 10 |
4.3 Length of stay (Emergency Department / in-hospital) | 22 | | 16 |
5. Outcomes | | 9.3% | |
5.1 Disposition after visit to the Emergency Department | 228 | | 49 |
5.2 Unscheduled returns / re-admissions b | 3 | | 3 |
5.3 Scheduled follow-up visit after Emergency Department visit b | 2 | | 2 |
5.2 Mortality rate after Emergency Department admission | 43 | | 23 |
General surgery in the ED |
1. Admission to the Emergency Department | | 5.7% | |
1.1. Volume of Emergency Department visits | 101 | | 17 |
1.2. Clinical severity at admission | 68 | | 19 |
2. Diagnosis | | 0.3% | |
2.1. Volume of diagnostic procedures | 8 | | 4 |
3. Treatment | | 3.3% | |
3.1. Volume of emergency surgeries | 30 | | 10 |
3.2. Change in treatment approach | 43 | | 19 |
3.3. Length of hospital stay | 19 | | 20 |
4. Outcomes | | 0.9% | |
4.1 Post-operative complications | 10 | | 8 |
4.2 Mortality rate | 16 | | 12 |
a A total of 298 indicators were not included in the analysis since they were too specific to be grouped into categories.
b Indicator retrieved in low numbers therefore it is not mentioned in the text and a trend was not computed.
Indicators related to general emergent and urgent care
Indicators and their trends were collated according to the acute care pathway (pre-hospital services, admission to the emergency department, diagnosis, treatment, and outcomes), which are outlined as follows (Fig. 2).
1- Pre-hospital services
Volume of patients contacting Emergency Medical Services
A total of 225 indicators from 20 studies (42–61) assessed the volume of patients contacting Emergency Medical Services (EMS). From those, most of the indicators (n = 110; 49%) showed a decreasing trend. These data came predominantly from Australia (n = 73 indicators; 33%) and Canada (n = 55 indicators; 24%).
One systematic review (62) reporting data from Australia, France, Italy, Spain, and the USA showed an increase of 120% in the number of out-of-hospital cardiac arrest (OHCA) events when comparing the year 2020 with a previous period.
Volume of bystander cardiopulmonary resuscitation
Twenty-six indicators from 10 studies (42, 50, 53, 54, 59, 60, 63–66) evaluated the volume of bystanders providing first aid in collapsed patients out-of-hospital. These indicators revealed, in most cases, a decreasing trend (n = 13;50%). Most data were from the USA (n = 9;35%) and France (n = 6;23%). Similarly, one systematic review (62) documented a decrease in bystander cardiopulmonary resuscitation (BCPR) rates during the pandemic, although not statistically significant. Two meta-analyses (67, 68) revealed no statistical difference in BCPR rates.
Proportion Of Patients With Ohca Witnessed By Bystanders
Twelve indicators from 9 studies (42, 50, 53, 54, 59, 60, 63–65) reported on the proportion of patients with OHCA witnessed by bystanders, most of those (7;59%) showed stability in this proportion.
Pre-hospital Treatment Times
The analysis of the treatment times in the pre-hospital setting revealed 59 indicators from 12 studies (42, 44, 46, 49, 51, 53, 57, 59, 63–66), predominantly from Australia (n = 14; 27%) and Finland (n = 12;20%). Most indicators (n = 41;70%) signaled an increasing trend. The treatment times assessed included: “response time: start of an emergency call to the arrival of the first ambulance at the scene” (57), “activation time: from the time someone reports to EMS to the time EMS departure” (66), “on-scene time: from the time arrival at scene to the time of departure for hospital” (66), “transport time: departure from the scene to arrival at the hospital” (57), among others. Similarly, the systematic reviews that assessed pre-hospital treatment times (62, 67, 69) documented significantly increased times from OHCA to ambulance arrival during the pandemic.
Survival Rate Of Patients With Out-of-hospital Cardiac Arrest
Concerning the survival rate of patients with out-of-hospital cardiac arrest, 81 indicators from 14 studies (42, 45, 46, 49–51, 53, 54, 58–60, 64, 66, 70) were identified. These indicators included the following sub-categories of indicators: “on-scene death rate”, “rate of pre-hospital return of spontaneous circulation (ROSC)”, “survival rate to hospital admission”, and “survival rate to hospital discharge”. Most indicators (n = 61;75%) signaled a decreasing trend in survival rates. Data came predominately from Spain (n = 44;62%) and the USA (n = 20;26%). Similarly, three of the systematic reviews documented a significant increase in the mortality rate following OHCA during the pandemic (62), lower rates of pre-hospital ROSC (68, 69), decreased survival rates to hospital admission (68) and to hospital discharge (68, 69).
2- Admission to the Emergency Department
Volume Of Emergency Department Visits
A total of 1066 indicators from 87 studies (44, 46, 55, 61, 70–152) provided information on the volume of patients admitted to the Emergency Department. From these, 752 (71%) indicators displayed a decreasing trend. Most of the data came from the USA (n = 309;29%), Italy (n = 163;15%), and the UK (n = 122;11%).
Arrival Mode To The Emergency Department
Three indicator categories were identified regarding the arrival mode of patients to the ED. A total of 16 indicators from 9 studies (61, 71, 75, 80, 87, 104, 118, 127, 131) assessed the volume of patients arriving with their own transport, from which 15 (94%) indicators showed a decreasing trend. Twenty-two indicators from 12 studies (46, 61, 71, 75, 80, 85, 104, 106, 118, 127, 131, 153) evaluated the volume of patients reaching the ED with the Emergency Medical Services. Most indicators (13;57%) signaled a decreasing trend. One study from Germany (104) displayed 40 indicators evaluating the number of ED admissions with a referral by a doctor related to different diseases; of those, 29 (72%) indicators showed a decreasing trend.
Level Of Urgency By A Triage System
A total of 51 indicators from 31 studies (46, 56, 71, 74–76, 80, 82–85, 91, 92, 96, 97, 99, 102, 107, 110, 113, 117, 118, 120, 124–126, 128, 131, 136, 138, 152) were identified regarding patients presenting with level 1/highly urgent conditions to ED, mainly from the USA (n = 21;41%) and Italy (n = 13;25%). Of these indicators, 51% (n = 26) signaled a decreasing trend. Of 36 indicators from 26 studies (46, 56, 71, 74–76, 80, 82, 85, 91, 92, 96, 97, 99, 102, 107, 117, 118, 120, 124, 128, 131, 136, 145, 151, 152) reporting on the volume of patients presenting with level 2/urgent conditions to ED, 56% (n = 20) reported a decreasing trend. These data came predominantly from the USA (n = 14;39%) and Italy (n = 6;16%). Concerning the stable conditions/levels 3 and 4, 46 indicators from 22 studies (46, 56, 71, 75, 80, 85, 91, 92, 96, 102, 107, 110, 113, 117, 120, 124, 125, 128, 131, 136, 138, 152) provided information on indicators’ trends from 7 countries. Most of these indicators reported a decreasing trend (n = 31;67%). Data came mainly from the USA (n = 23;50%). Concerning non-urgent/level 5 conditions, a total of 55 indicators from 32 studies (46, 56, 71, 74–76, 80, 82–85, 91, 92, 96, 102, 107, 110, 113, 117, 118, 120, 124–126, 128, 131, 136, 138, 145, 150–152) were identified. Of these, 78% (n = 43) reported a decreasing trend in the volume of these patients. Data were reported predominantly from the USA (n = 20;36%) and Italy (n = 15;27%).
Clinical Severity At Admission
Regarding patients’ clinical severity at admission, 26 indicators from 8 studies (77, 97, 114, 130, 137, 153–155) were identified. Most indicators reported an increasing trend (n = 18;69%). Data were reported mainly from the UK (n = 8.31%) and Switzerland (n = 5;19%). The indicators retrieved were related to the overall severity of medical admissions (114), clinical severity of patients diagnosed with urolithiasis (130), diverticulitis (154), pyelonephritis (77), pulmonary embolism (97), chronic obstructive pulmonary disease (137), and appendicitis (153).
3- Diagnosis
Volume Of Diagnostic Procedures
Information on the volume of diagnostic procedures in the ED was retrieved from 131 indicators from 16 studies (76, 80, 86, 89, 97, 107, 119, 139, 154–161) reporting on 8 countries. They displayed information regarding laboratory testing (156, 162), ultrasound imaging (80, 160), radiological examinations (80, 86, 97, 119, 139, 154–161), nuclear imaging (80, 160), and biopsies (89). Most of the indicators reported on computed topographies (CT) (n = 64;49%) and laboratory testing (n = 16;6%). The predominant trend was a decrease in the volume of diagnostic procedures (n = 85,65%) (trends for each diagnostic procedure are detailed in Additional file 5). Data came predominantly from the USA (n = 74 indicators;56%) and Italy (n = 19;14%).
Rate Of Positive Findings After Diagnostic Testing
A total of 32 indicators from 4 studies reporting on 4 countries were retrieved regarding the rate of positive diagnostic findings, namely positive blood cultures (156) and positive CT findings (86, 155, 156, 158). Of these, 9 (58%) indicators displayed an increasing trend. Most indicators were from the USA (n = 18; 55%) and Ireland (n = 7; 21%).
4- Treatment
Volume Of Therapeutic Interventions
A total of 106 indicators from 18 studies (61, 76, 77, 82, 86, 87, 89, 92, 93, 102, 130, 142, 145, 149, 153, 155, 163, 164) and 11 countries reported on therapeutic interventions in the ED. Most indicators signaled a decreasing trend (n = 54; 51%). The therapeutic interventions assessed were invasive procedures (e.g., endoscopy, endovascular intervention, endoscopic retrograde cholangiopancreatography, paracentesis/thoracentesis), acute surgical interventions, and other procedures, such as bedside procedures.
Operational Times
Seventeen indicators from 10 studies and 7 countries reported on the average operational times for emergent and urgent care, such as average waiting time for triage (117, 161), from triage to first medical assistance (46, 117, 120, 124), from consultation to treatment (46, 84, 142, 155, 156), and for hospital ward admission (125). Of these, 9 (53%) indicators signaled a decreasing trend.
Length Of Stay
A total of 14 indicators from 11 studies (46, 80, 85, 92, 108, 114, 120, 124, 139, 145, 151) reported on the length of stay (LOS) in the ED, from which 11 (79%) indicators displayed a decreasing trend. Concerning the in-hospital LOS after ED admission, 8 indicators from 5 studies (121, 124, 133, 137, 153) were retrieved, from which 62% (n = 5) reported a decreasing trend.
5- Outcomes
Disposition After Ed Visit
Concerning the volume of patients discharged home, a total of 26 indicators from 15 studies (46, 76, 80, 92, 96, 106, 107, 110, 111, 114, 124, 130, 145, 151, 152) and 5 countries were retrieved. Most indicators (n = 15;58%) reported a decreasing trend. Regarding the volume of hospital admission after ED presentation (including admission to intensive care unit), from the 191 indicators from 46 studies (46, 61, 71, 72, 75, 77, 79–82, 84–88, 90, 92, 94, 96, 97, 101, 102, 106–111, 114–117, 121, 122, 124, 125, 128, 131, 138, 139, 141, 143, 145, 146, 151, 152) collected, 52% (n = 100) signaled a decreasing trend, and 39% (n = 74) showed an increasing trend. Most of the indicators were from the USA (n = 43;23%), Italy (n = 35;18%), and Croatia (n = 23;12%). Eleven indicators from 7 studies (71, 92, 107, 124, 145, 151, 165) and 3 countries reported on the volume of patients leaving the ED without completing treatment, including patients that left the ED without being seen, completing treatment, and against medical advice; of these, 9 (82%) indicators signaled a decreasing trend.
Mortality Rate
A total of 43 indicators from 23 studies (44, 46, 61, 70, 79, 85, 86, 90, 92, 101, 107, 114, 117, 121, 124, 127, 131, 133, 137, 143, 147, 151, 156) reported on the mortality rate after an ED visit. Most of the indicators signaled an increasing trend (n = 23;53%). Data came predominantly from Canada (n = 9;21%), Turkey (n = 6;14%), and Norway (n = 5;11%).
Trend analysis by country and clinical entity did not show recognizable tendencies in any of the indicators retrieved (Additional file 5). The trends of the indicator categories related to general acute care comparing the COVID-19 period to a previous period are displayed in Fig. 2.
Indicators related to acute general surgery care
Indicators on acute general surgery care were collected and grouped following the care pathway (admission, diagnosis, treatment, and outcomes), and their respective trends are summarized in Fig. 3.
1- Admission
Volume of Emergency Department visits
A total of 101 indicators from 17 studies (166–182) and 10 countries reported on the volume of ED visits related to acute general surgery. Of those, almost half of the indicators (n = 50;49%) signaled a decreasing trend. Most of the data were from Canada (n = 19;18%), the UK (n = 14;14%), and New Zealand (n = 12; 12%).
Clinical severity at admission
Indicators assessing patients’ clinical severity included clinical, laboratory and imaging features at admission, severity grading according to diseases-specific scores, operative findings, and the American Society of Anesthesiologists (ASA) score. Sixty-eight indicators were retrieved from 19 studies ; of those, 36 (53%) indicators showed a stable clinical severity and 29 (43%) indicators signaled increased severity. The countries most represented were the USA (n = 19;28%), Israel (n = 15; 22%), and the UK (n = 11;16%).
2- Diagnosis
Eight indicators from four studies evaluated the diagnosis phases of the pathway, which did not provide sufficient information regarding trends.
3- Treatment
Volume of emergency surgeries
Data related to the volume of acute surgeries was retrieved from 30 indicators and 10 studies (168, 170, 179, 180, 182–187), from 8 countries. Most of the indicators (n = 14;47%) signaled stability in the volume of acute surgeries. Data came predominantly from Italy (n = 16;54%).
Change in treatment approach
A total of 43 indicators from 19 studies (167–171, 173, 174, 176, 177, 180, 182–185, 188–192) were retrieved. These indicators evaluated the treatment strategy in the acute surgical setting related to diseases such as appendicitis, acute cholecystitis, and bowel obstruction. Most of the indicators (n = 28;65%) signaled no change in the treatment approach. Data were predominantly from the UK (n = 12;28%) and Germany (n = 9;21%).
Length of hospital stay
Concerning the LOS in-hospital (including in the intensive care unit), 25 indicators from 20 (169–175, 177, 178, 180, 183–185, 187–193) studies were collected. Most of the indicators showed stability of the LOS (n = 19;76%). Data came mostly from the UK (n = 7;28%), USA (n = 4;16%), and Ireland (n = 4; 16%).
4- Outcomes
Post-operative complications
Ten indicators from 8 studies (168, 169, 173, 176, 180, 188–190) reported on post-operative complications. Most of these indicators (n = 7;70%) signaled stability in this outcome.
Mortality rate
Concerning the mortality rate, 16 indicators from 12 studies (168, 170–172, 176, 177, 180, 181, 183, 184, 189, 192) were collected. Of these, 69% (n = 11) signaled stability.