Increasing emergency number utilisation is not driven by low-acuity calls: an observational study of 1.5 million emergency calls (2018-2021) from Berlin

Abstract

Background: The Emergency Medical Service (EMS) in Germany is increasingly challenged by strongly rising demand. Speculations about a greater utilisation for minor cases have led to intensive media coverage, but empirical evidence is lacking. We investigated the development of low-acuity calls from 2018 to 2021 in the federal state of Berlin and its correlations with sociodemographic characteristics.

Methods: We analysed over 1.5 million call documentations including medical dispatch codes, age, location and time using descriptive and inferential statistics and multivariate binary logistic regression. We defined a code list to classify low-acuity calls and merged the dataset with sociodemographic indicators and data on population density.

Results: The number of emergency calls (phone number 112 in Germany) increased by 9.1% from 2018 to 2021; however, the proportion of low-acuity calls did not increase. The regression model shows higher odds of low-acuity for young to medium age groups (especially for age 0-9, OR 1.50 [95% CI 1.45-1.55]; age 10-19, OR 1.77 [95% CI 1.71-1.83]; age 20-29, OR 1.64 [95% CI 1.59-1.68] and age 30-39, OR 1.40 [95% CI 1.37-1.44]; p < 0.001, reference group 80-89) and for females (OR 1.12 [95% CI 1.1-1.13], p < 0.001). Odds were slightly higher for calls from a neighbourhood with lower social status (OR 1.01 per index unit increase [95% CI 1.0-1.01], p < 0.05) and at the weekend (OR 1.02 [95% CI 1.0-1.04, p < 0.05]). No significant association of the call volume with population density was detected.

Conclusions: This analysis provides valuable new insights into pre-hospital emergency care. Low-acuity calls were not the primary driver of increased EMS utilisation in Berlin. Younger age is the strongest predictor for low-acuity calls in the model. The association with female gender is significant, while socially deprived neighbourhoods play a minor role. No statistically significant differences in call volume between densely and less densely populated regions were detected. The results can inform the EMS in future resource planning.

Keywords: 112; 999; Ambulance; Emergency Medical Service; Emergency calls; Emergency medicine; Low-acuity; Overload.

Fig. 1

Data flow chart. Source: Own illustration

Fig. 2

Temporal development from 2018 to 2021 of A the number of emergency calls and B the population of Berlin. Source: A Data of the EMS Berlin and B data of the Office for Statistics Berlin-Brandenburg

Fig. 3

Temporal development of low-acuity and high-acuity emergency calls from January 2018 to December 2021. Source: Data of the EMS Berlin

Fig. 4

A Number of low-acuity and high-acuity calls per age group in 2021 and B difference between 2018 and 2021. NAs of MPDS category have been included to correctly plot the total call numbers and to show the increasing protocol adherence (decrease of NAs) over time. Source: Data of the EMS Berlin

Fig. 5

Distribution of MPDS protocols (first element of the MPDS code, chief complaint) and proportion of low-acuity calls in 2021. Source: Data of the EMS Berlin. Protocols: 1: Abdominal pain, 2: Allergies/envenomations, 3: Animal bites/attacks, 4: Assault/sexual assault, 5: Back pain, 6: Breathing problems, 7: Burns/explosions, 8: Carbon Monoxide/inhalation, 9: Cardiac or respiratory arrest/death, 10: Chest pain, 11: Choking, 12: Convulsions/seizures, 13: Diabetic problems, 14: Drowning/diving, 15: Electrocution/lightning, 16: Eye problems, 17: Falls, 18: Headache, 19: Heart problems, 20: Heat/cold exposure, 21: Hemorrhage/lacerations, 22: Inaccessible incident, 23: Overdose/poisoning, 24: Pregnancy/childbirth/miscarriage, 25: Psychiatric/suicide attempt, 26: Sick person, 27: Stab/gunshot/penetrating trauma, 28: Stroke/transient ischemic attack, 29: Traffic incidents, 30: Traumatic injuries, 31: Unconscious/fainting, 32: Unknown problem, 33: Inter-facility transfer/palliative care, 34: Automatic crash notification, 35: Health-care practitioner referral, 36: Pandemic/epidemic/outbreak, 37: Inter-facility transfer specific to medically trained callers

Fig. 6

Comparison of densely populated (> 3000 inhabitants per km²) and less densely populated PGRs regarding mean number of calls in 2021. A Mean of emergency calls per 100,000 inhabitants in a PGR in the years 2018–2021. B Histogram plotting all PGRs depending on the rate of emergency calls per 100,000 inhabitants in 2021. Vertical lines represent the means for densely populated (red) and less densely populated (blue) PGRs. The differences between densely and less densely populated PGRs were not statistically significant. Source: Data of the EMS Berlin and of the Senate of Berlin

Fig. 7

Age distribution of low- and high-code emergency calls per district of Berlin and per acuity in 2021. Source: Data of the EMS Berlin