We conducted a retrospective cohort study that included all EMS calls in the HUH area between 1 January and 31 July 2020 (study period). Data from EMS calls in 2018 and 2019 for the corresponding dates were used as reference (control period). The study plan and the conduction of the study were approved by the Institutional Review Board of Research and Education, Department of Emergency Medicine & Services, Helsinki University Hospital (HUS/247/2020). The aforementioned Board waived the need for ethics committee approval. Also, the Board waived the need for informed consent from patients. These waivers were based on Finnish research legislation, the Finnish Medical Research Act (488/1999). The study protocol was performed in accordance with the relevant guidelines. We reported the study in accordance with the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guideline .
Study setting and population
Finland is a Nordic country with 5,500,000 inhabitants. Our study area, the HUH catchment area, is formed by the capital area of Helsinki and neighboring municipalities and has a total catchment population of 1,263,000 . Although Helsinki is the largest urban center in Finland, the study area also contained less populated and rural areas.
Emergency medical service
All emergency calls, regardless of type of emergency, are made to single number (112) and are handled by the national Emergency Response Center (ERC). The ERC operator handling the call follows a systematic questionnaire to assess the emergency and each mission is assigned a code that indicates the type of symptom, accident, injury, or violence. The ERC operator then dispatches the appropriate emergency services (i.e. rescue department, police, EMS, and other relevant agencies). Dispatched EMS units are assigned a triage class from A to D. Triage class A indicates a high-risk, life threatening situation with severe disturbance in vital signs or a high-risk injury. Class B indicates a situation in which there is a disturbance in vital signs that might progress to be life-threatening without prompt EMS interventions. Class A and B missions are responded to immediately with lights and sirens on. Class C indicates a situation where patient is stable and can wait for an ambulance. EMS responds within 30 min. Class D indicates a non-urgent situation. EMS responds within 120 min. Class C and D missions are responded to without lights and sirens on and by observing speed limits and regular traffic rules.
EMS in the HUH area is organized by the HUH and provided by three fire departments and two contracted private operators all operating under the same medical and operational guidelines. Ambulances are staffed by emergency medical technicians and paramedics. More advanced care in the area is provided by three on-duty medical supervisors and two prehospital physician units mainly responding to triage class A missions.
The Finnish government response to the COVID-19 pandemic
On 12 March 2020, the Finnish government recommended canceling all mass gatherings and sport events and for all employees to work remotely from home if possible. The government declared a state of emergency on 16 March and implemented the Emergency Powers Act one day later. As a result, all gatherings of over 10 persons were banned, and schools and other educational institutions switched to distance learning with the exceptions of grades 1 to 3. Kindergartens were kept open only for children of persons employed in sectors critical to the functioning of society. All sport and culture venues were closed. Visits to institutional care facilities for the elderly were prohibited. Persons of over 70 years of age were instructed to self-quarantine. Many non-urgent health care services were suspended. Non-essential domestic and international travel was prohibited. Due to a regional spike in infections, Uusimaa, which is a region of 1,700,000 inhabitants and includes the capital Helsinki, was isolated from the rest of the country for the period from 28 March to 15 April. All restaurants, bars and nightclubs closed on 4 April at the latest, but many closed voluntarily before the deadline.
The relaxation of restrictions started with schools resuming classroom teaching on 14 May. On 1 June, many culture and sports venues and restaurants reopened and mass gatherings of up to 500 persons were permitted [15, 16].
The HUH EMS uses an electronic health record (Merlot Medi®, CGI Finland Oy) and all EMS missions in the HUH area are registered in a single database. Patient data, including vital sign measurements and interventions are marked in the record. Alcohol intoxication is assessed by a breathalyzer test when it is suspected even slightly, and the blood alcohol level is marked in the record. In cases where patient refuses, or their condition does not allow for a breathalyzer test to be performed EMS personnel uses their clinical judgement. In such cases alcohol intoxication is marked as “positive” when it is obvious or if information concerning the patients’ alcohol use is available from other persons on scene. In addition to the patient data, mission data such as dispatch and transportation times, mission and triage codes, and possible non-conveyance data are recorded in the electronic health record.
We analyzed all EMS calls in the HUH area during the study and control periods. Calls were divided into the following three time periods: 1 January to 8 March “pre-lockdown”; 9 March to 31 May “lockdown”; and 1 June to 31 July “post-lockdown”. Trauma-related dispatch codes were identified; of these, all traffic injuries (i.e. road, rail, boat accidents), violence-related injuries (i.e. assaults, stabbings, shootings), and accidental injuries (i.e. falls, impacts, wounds, drownings, fire or chemical related injuries, electrocutions) were analyzed.
The “lockdown” period was determined to have started 1 week before the declaration of the state of emergency because of rising COVID-19 infection incidence, heavy press coverage on the subject, and unofficial calls for social isolation. The “lockdown” period was decided to have ended on 1 June, when restaurants, bars, and nightclubs were reopened and the restrictions on public gatherings were relaxed.
We analyzed separately the number of trauma-related EMS contacts for persons aged 0–16 years during school and kindergarten operation restrictions from 16 March to 14 May.
The data are described using medians and interquartile ranges (IQR) and counts and percentages. Comparisons were performed for the number and percentage of weekly events using Mann-Whitney U test. Due to large dataset, P-values < 0.01 were considered significant. Analyses were performed using R version 3.6.3 and the ggplot2 package.