The COVID-19 pandemic has major repercussions on various health domains, such as a significant increase in population mortality and a decrease in life expectancy in most European countries [22, 23]. Looking at the changes and variations in the prehospital emergency demands before and during the COVID-19 pandemic, changes in the patient population requesting an ambulance during 2020 are found and are significant. This is consistent with what was expected, as ambulance emergency demands due to COVID-19 disease symptoms increased. Interestingly, collateral effects that are not related to the disease itself are also found and appear to relate to government protective measures. Changes vary according to age groups, health issues and severity of a health problem.
Both pandemic and social distancing measures impact EMS demands
Several health issues increased during the COVID-19 pandemic. A concordance between health issues related to respiratory distress and the successive epidemic waves in March and October 2020 is observed. Such concordance can be explained by predominantly respiratory symptomatology in COVID-19 and has been found in other studies (e.g. Satty et al. ). Additionally, from the start of the epidemic, an increase of at least 20% in ambulance transport due to the impossibility of treating patients in their home is observed: it peaks at a 96% increase in October 2020 and highlights the challenges of taking care of nonurgent but vulnerable individuals.
Interestingly, in 2020, there was a significant decrease of more than 20% in trauma and intoxication in March and April 2020 compared to the average value in 2018–2019. The decrease in the trauma category can be explained by the implementation of a semiconfinement that was associated with governmental restrictions such as semiconfinement, home office, school closure, bar and restaurant closures, and recommendations of restriction of many activities such as driving, traveling, or engaging in high risk sports (skiing or mountain biking, for instance). This trend has also been observed in various countries, such as Israel  and Finland [26, 27]. In Switzerland, a significant decrease in major trauma arriving at the emergency department has been measured during the governmental restriction phases . The causes of trauma related to traffic accidents, for example, decreased by 17% compared to 2019 . The measured reduction in cases of intoxication is certainly related to the complete or partial closure of bars, restaurants, and nightclubs as well as limitations of private gatherings during the epidemic’s waves in 2020. A similar trend was reported in Israel during the first lockdown period in March and April 2020, with a 23.65% decrease in overdoses compared with the previous year , as well as in Finland, with a decrease in alcohol-related intoxications .
The significant excess of cases of allergy in August might be related to both the environment and protective measures to the population. First, good meteorological conditions for outdoor activities occurred in Switzerland, and the second protective measure encouraged the population to spend time in the countryside and natural area, as all public places for entertainment were closed. However, such a relationship might require further analysis to be proven.
Seniors where the most impacted
An increase in the number of primary missions from the population aged 65 years and older is measured. This increase is mainly observed in the following health problems: health care impossible at home and declined general condition. This could probably be explained by the reduced availability of family caregivers during the semicontainment period (working at home with dependent children, fear of transmitting the virus, gathering of people prohibited, etc.) and on the other hand by a decrease in social and health services offered to the older population, such as animations or meals in community and closure of senior day care centers. Fear of infection might have influenced the use of general health services and informal care . It is also possible that existing vulnerabilities in the senior population were exacerbated during the pandemic. Such a trend has been observed in several studies that found a significant decrease in the senior population in the emergency department during epidemic waves [29, 30].
Reduced part of transported patients
The number of nontransported patients increased in 2020. These findings are reported in many countries during the COVID-19 pandemic with varying proportions depending on the pandemic context and health authority responses. In Israel, the share of nontransported workers increased from 13.4% to 2019 to 19.9% in 2020. The authors suggest that this increase may be related to patients’ fear of possible SARS-CoV-2 related contamination if transported to the hospital during the height of the pandemic. In addition, the authors point out that these nontransports may have been the cause of a deterioration in the health status of patients who refused transport until the later stages of illness . Another Finnish study also found an increase in nontransported patients during the first COVID-19 epidemic wave from 36.1% to 2019 to 39.9% in 2020 for the same period analyzed (P < 0.001) . Another American study conducted in the state of Pennsylvania also found a 48% relative increase in nontransports during the first pandemic period .
Targeted services might be the key
When looking at EMS demands and missions during the pandemic, the population aged 65 years and more appears to be the most affected by both the pandemic and social distancing measures. The significant increase in the health issues category “Declined general condition” and “Health care impossible at home” both might signal a leak of support of this population at their home. Indeed, caregivers (family members or friends) might not have been available for seniors due to many factors, such as school closures, quarantines, and fear of infecting senor individuals. Additionally, many care centers, which take care of approximately 2100 persons in the canton on a yearly basis, were closed during the pandemic, resulting in less professional surveillance during the daytime . Additionally, general health check-ups and follow-up of chronic conditions were temporarily cancelled or replaced by telemedicine. Such results point out the importance of the community of caregivers, the small structures that offer meals and activities for the senior community. It might thus signal a need for targeted intervention for seniors during pandemics. The greater representation of this population also uncovers needs in terms of training for the ambulance crew that require skill to take care of complex situations and adapt interventions to their needs.
A recently published editorial stresses the importance of reflecting on the integration of emergency medical services in a more community-based approach centered on the principle of regionalization of resources and care networks in the interests of efficiency . Among others, they highlight as a previous study  a need for a better match between ambulance emergency demands (social, health issues, severity, age) and ambulance emergency resources (workload, location, skills required). This might be a necessary step for an adaptive response in handling complex emergency demands during the pandemic.
Prevention measures and follow-up of chronic conditions could be considered and targeted to certain categories of the population during future pandemics. The prevention of risks related to vulnerability factors such as age should be considered relative to these research results, with, for example, the establishment of a support and follow-up network for the population aged 65 and over. Such actions could also have many additional benefits and prevent the currently observed unnecessary use of emergency departments by old patients [34,35,36,37]. A structured collaboration between paramedics, nurses, social emergency services, psychiatric emergency services, home care and palliative care might provide an adapted response to future pandemics and to other disasters related to climate change.
This research provides critical information on prehospital activity that does not benefit from large-scale monitoring, although detailed good-quality data are available to public authorities. Indeed, statistics on emergency demands by the population are generally missing in Switzerland. For example, the recent report on the impact of the COVID-19 pandemic on health care services in 2020  did not mention prehospital-associated community services and their professionals, which include ambulance services, nurses, social emergencies, psychiatric emergencies, and palliative care. Little is known about the consequences of the pandemic on their activity and their patients. They all appear critical to an adapted and targeted prehospital health care system. Bridging the gap between researchers, clinicians, decision-makers, and available data is of critical importance to better prepare for future epidemic events or other natural disasters.
Limitations of the research study
Generalization of our findings should be made with caution, as our study does have some limitations. First, implemented emergency responses to the pandemic and deployed social distancing measures for the population were specific to Switzerland. For example, gathering was prohibited and teleworking was generalized during lockdown (semiconfinement), but the population was allowed to do outdoor activities. Second, information bias might exist, as the collected data are concerned with emergency demands made via dispatch emergency centers where an ambulance was requested and might thus not represent all the emergency demands that occurred during the studied period. Third, the health issues considered have been identified during the emergency mission by the ambulance crew and are not a formal health diagnostic. Finally, although the amount of data available is very large, when comparing years (here only 3 years) and months across years, the sample size is markedly reduced. Consequently, detecting a true effect is reduced due to the low statistical power.