Abstract
Introduction
Alcohol consumption is associated with an increased risk of accidents, and previous studies have shown that alcohol-related harm places a significant burden on emergency departments. The aim of this study was to estimate the proportion of ambulance contacts in the Capital Region of Denmark related to alcohol from 9 March 2015 to 30 April 2024, and to characterise these contacts, focusing on differences across sex and age groups.
Methods
We conducted a descriptive study based on information from urgent ambulance contacts in the Capital Region of Denmark. The study population included patients aged 15 years and older. Alcohol-related ambulance contacts were identified using a two-step approach: an automated keyword search in prehospital medical records followed by manual verification. The main outcome measures were proportions and relative proportions (RPs) of ambulance contacts related to alcohol.
Results
We estimated that 6.2% of all ambulance contacts in the Capital Region of Denmark were alcohol-related. The proportion was significantly higher in males compared with females (RP 2.03 (95% CI 1.92 to 2.14)). Alcohol-related contacts were most prevalent in those aged 15–24 years (17%), and least prevalent in those aged 70 years or older (1.9%). The proportion of ambulance contacts being alcohol-related was highest on Fridays (10%) and Saturdays (9.8%), peaking at night-time. The most common causes of alcohol-related contacts were accidents (38%) and acute alcohol intoxication (26%). We observed an age-related shift in the cause of contact, with the proportion of accidents increasing and the proportion of acute intoxication decreasing with advancing age.
Conclusions
6.2% of urgent ambulance contacts in the Capital Region of Denmark were alcohol-related, with substantial variations across sex and age. This emphasises a need for targeted preventive measures reducing acute alcohol-related harms and consideration of targeted prehospital resources.
Keywords: Age Factors, Sex Factors, Public Health, Emergencies, Epidemiology
WHAT IS ALREADY KNOWN ON THIS TOPIC
Excessive alcohol consumption is associated with impaired motor and cognitive functions, thereby increasing the risk of acute accidents.
Immediate alcohol-related harm places a burden on emergency departments, yet few studies have examined its impact on prehospital medical services. To our knowledge, the causes of acute alcohol-related ambulance contacts have so far only been examined in adolescents.
WHAT THIS STUDY ADDS
This study contributes to knowledge regarding the significant burden of alcohol on urgent ambulance contacts, highlighting distinct patterns across sex and age groups.
HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY
Insights from this study underscore the need for targeted preventive measures to reduce alcohol-related harms and to enhance the efficient allocation of prehospital emergency resources.
Introduction
Alcohol consumption and its associated harms are major contributors to the global burden of disease and injury.1 2 According to the WHO, alcohol was responsible for approximately 4.7% of all deaths and 4.6% of disability-adjusted life years (DALYs) worldwide in 2019.3 Alcohol-related injuries, including traffic incidents, self-harm and interpersonal violence, accounted for 17.7% of all injury-related deaths and 17.5% of DALYs.2 4 Alcohol-related harm is notably higher among males (6.9% of DALYs) compared with females (2.0% of DALYs), and disproportionately affects younger adults, with the highest alcohol-attributable mortality observed among those aged 30–34 years.3
The WHO reports that the European Region has the highest levels of alcohol consumption globally, with an average annual intake of 9.2 L of pure alcohol per person.3 In most European countries, binge drinking becomes prevalent during the mid-late adolescent period,5 6 and alcohol consumption is often perceived as a social activity that fosters interpersonal connections and enhances individuals’ social image, often contributing to the perception of them as sociable and extroverted.7 However, consumption patterns tend to shift with age, with older age groups being more likely to engage in habitual alcohol consumption.8 9
The negative impacts of excessive alcohol consumption are extensive, ranging from immediate effects to long-term consequences. An elevated blood alcohol concentration impairs motor skills and cognitive functions, leading to noticeable symptoms such as slurred speech and poor coordination. These impairments, combined with reduced critical judgement and increased risk-taking behaviour, increase the likelihood of acute accidents, including falls, traffic incidents and violent episodes.10
The harmful effects of alcohol extend beyond the individual, impacting families, friends and society, while also imposing significant economic burdens on healthcare systems.11 12 Alcohol intake can necessitate emergency medical attention, but studies examining the acute harms related to alcohol intake are primarily conducted in emergency departments. British, Australian and New Zealand studies have estimated that between 9.5% and 21% of adults presenting to emergency departments are intoxicated by alcohol, with this proportion increasing to between 14% and 28% during weekends.13,15 While emergency departments capture a significant portion of alcohol-related incidents, the number of alcohol-related contacts within the broader healthcare system may be underestimated, as many cases managed by emergency medical services receive immediate care and, for some patients, represent their only interaction with the healthcare system.16 17
Few studies have investigated the prehospital burden of alcohol-related contacts to the emergency medical service. Recently, one study in the Capital Region of Denmark found that 16% of ambulance contacts among individuals aged 15–24 years were alcohol-related.18 Similarly, studies from the UK estimated that between 10% and 16% of all ambulance contacts were alcohol-related, with variations across sex and age groups.12 19 Despite these findings, knowledge regarding the prevalence and characterisation of acute alcohol-related ambulance contacts remains limited, and the causes of these contacts have only been examined in adolescents.18 Understanding the distribution of alcohol-related ambulance contacts and their causes across different life stages is crucial for assessing the burden on the healthcare system, optimising healthcare responses and guiding targeted public health policies and interventions.
The aim of this study was to estimate the proportion of alcohol-related ambulance attendances among individuals aged 15 years and older in the Capital Region of Denmark using a random sample of contacts from a 9-year period. An additional aim was to characterise these contacts with a focus on differences across sex and age groups.
Materials and methods
We conducted a descriptive, population-based study on ambulance contacts in the Capital Region of Denmark among patients aged 15 years and older, spanning the period from 9 March 2015 to 30 April 2024. Data were sourced from medical calls and ambulance services in the Capital Region of Denmark, which provides emergency medical services to approximately 1.9 million citizens, representing 32% of the Danish population. The region encompasses both the capital city of Denmark, Copenhagen, as well as rural and urban areas.
We included two urgent ambulance response types: (1) level A, requiring an immediate response with sirens, and (2) level B, which has a response time within 25 min.16 20 Other response types, which represent non-urgent or scheduled transports, were excluded due to their low frequency and limited relevance to acute, alcohol-related contacts. In the Capital Region of Denmark, prehospital emergency medical services can be accessed through two telephone numbers, both of which redirect acute health-related calls to the emergency medical coordination centre (EMCC), responsible for dispatching ambulances: (1) the emergency number (1-1-2), designated for potentially life-threatening situations, and (2) the non-emergency helpline (1813-MH), primarily intended for out-of-hours medical consultations.
Data flow and manual coding of free-text entries in the prehospital medical record (PMR)
At the EMCC, healthcare professionals responding to calls collect information regarding the patient and medical emergency, using a Computer Aided Dispatch System (LOGIS-CAD). They assess the type and severity of the medical problem using the Danish Index for Emergency Care,20 a criteria-based emergency dispatch system. Based on this assessment, the appropriate level of urgency is determined, which guides the selection of the corresponding response level.16 20 On-site, ambulance personnel generate a PMR, which includes a free-text field for documenting the event. Information regarding alcohol-related incidents is not captured by the standardised sections of the PMR. Therefore, ambulance personnel can only document information regarding alcohol consumption and intoxication in the free-text field. However, the information in free-text fields varies in detail and length. To identify alcohol-related contacts and extract other clinically relevant information not specified elsewhere in the records, we developed a two-step approach. First, we applied a search string to the PMR free-text fields using keywords to identify potentially alcohol-related medical records. second, we reviewed free texts from all PMRs flagged by the search string as possibly alcohol-related. This was done to confirm and register whether patients were genuinely intoxicated by alcohol and to manually extract additional information of interest from those confirmed to be alcohol-related.
For the first step, we used the search string developed by Bruun et al, which was developed through an iterative process to identify potentially alcohol-related PMRs by combining the terms ‘alcohol’ and/or ‘drunk,’ refining it based on the identification of false negatives.18 This process was repeated until further refinement of the search string no longer increased its sensitivity, indicating that nearly all alcohol-related contacts were captured. The search string included the following keywords (translated directly from Danish): ‘alcohol, drunk, intoxicated, inebriated, drink, drank, vodka, beer, units, detoxication, night out and dangle’ (’dangle’ is a translation of the Danish slang term ‘dingle’, which refers to walking unsteadily or staggering, typically due to alcohol intoxication). We further refined the search string to capture only exact matches of these keywords, as the Danish keywords often occurred as embedded words, causing false positive identifications. Finally, the search string was validated in a random sample of 2310 contacts by comparing the number of true alcohol-positive and true alcohol-negative identified by the search string to those identified as alcohol positives and negatives by a manual verification conducted by a researcher. The sample size was estimated based on an expected proportion of alcohol-related ambulance contacts of approximately 10%,21 as reported in previous studies ranging from 10% to 16%,12 18 19 to ensure sufficient power to assess the sensitivity and specificity of the search string. We calculated the sensitivity and specificity of the search string to be 95% and 94%, respectively.
For the second step, the extraction and categorisation of free text from the PMR were carried out by five coders due to the large sample size. Each coder was assigned a unique set of contacts, and the same manual coding procedure as used for the validation of the search string was applied. This ensured high consistency between the different coders involved in the project. The standardised coding procedure included clear definitions of all variables and categories to be manually extracted from the free texts, including information on whether alcohol was involved and the primary cause of the ambulance contact. Inter-rater agreement between coders was evaluated in a sample using Cohen’s Kappa, showing substantial agreement for the two main variables obtained through manual coding (alcohol intoxication=0.90, primary cause of contact=0.84).
Variables
For all ambulance contacts, we included variables extracted from the CAD System, which provided structured data on patient and ambulance contact characteristics. For alcohol-related ambulance contacts, additional data were collected through manual coding of free texts from the PMRs. Age and sex were obtained from the personal identification number. Regional location was categorised based on the geographical area of the ambulance contact, with the city centre defined as the central areas of Copenhagen covering zip codes 1050–1499. The distal city centre was defined as areas surrounding the city centre covering zip codes 1500–1974, 2100 and 2200, while suburban and rural areas covered all other zip codes within the Capital Region of Denmark. The requestor was defined according to the source through which the medical call was initiated prior to ambulance dispatch, including 1-1-2, 1813-MH and other sources such as hospital wards, police or other direct contacts to the EMCC.
To align alcohol-related ambulance contacts with the relevant social context (eg, Friday night), day of the week was defined as a 24-hour period starting at 12:00 (midday) on a given day and ending at 12:00 the following day. Night-time hours were specified as 20:00–06:00. The week consists of 168 hours, starting at 12:00 on Monday. Weekends were defined as the period from 12:00 on Friday to 12:00 on Sunday. Termination of contact was categorised into two types: on-site termination and transfer to a hospital.
Coders determined whether an ambulance contact was related to alcohol based on documentation in the PMR free text. An ambulance contact was considered alcohol-related if the patient was intoxicated by alcohol at the time of the ambulance contact. If the patient was not explicitly described as drunk, intoxicated by alcohol, inebriated or with similar terms, the coder assessed additional details such as the amount of alcohol ingested, the patient’s behaviour and clinical signs, or blood alcohol concentration if available. Based on this information, coders determined whether the ambulance contact was related to acute alcohol use or not.
For contacts identified as alcohol-related, additional information was extracted from the PMR free-texts, including the primary cause of ambulance contact, the mechanism of accident and the body region of injury. The primary cause of ambulance contact was determined based on symptoms and medical assessments documented by ambulance personnel and categorised as accident, acute alcohol intoxication, symptoms of diagnosed somatic disease, psychiatric symptoms and violence. Accident mechanisms included falls, traffic accidents and a category of other types/not stated, and body region of injury was categorised as head/neck/face, extremities and a combined category for both.
Due to the source of the data, the occurrence of missing information was generally low. Missing data were observed for sex (<0.01%), termination of contact (0.5%) and regional location (0.8%). For all other variables, data were complete.
Final study sample
In the period between 9 March 2015 and 30 April 2024, 1 358 117 ambulance contacts occurred in the Capital Region of Denmark. Of these, 1 111 958 were eligible for inclusion in this study (figure 1). Due to the extensive manual coding of free texts from the PMRs, we were unable to include all eligible contacts. Thus, we drew a random study sample of 87 820 contacts, which allowed us to estimate the proportion of alcohol-related ambulance contacts with a maximum margin of random error of 2%, ensuring high precision in our estimate, even when stratified by age group.22
Figure 1. Flow chart of inclusion and exclusion criteria, sampling and application of search string.
Statistical analysis
The analysis employed descriptive statistics, presenting the numbers and proportions of alcohol-related ambulance contacts across each characteristic. Furthermore, the hour of the week, the regional location and the cause of ambulance contact were analysed in greater detail across sex and age groups. Univariable Poisson regressions estimated relative proportions (RPs) and 95% CIs, with alcohol-relatedness as the dependent variable and sex, age group, requestor, response level, contact termination, regional location and day of the week as independent variables. We use the term RP to refer to the proportion of alcohol-related ambulance contacts within a given subgroup compared with the proportion observed in a reference group. Cubic splines were used to model hourly fluctuations throughout the week, with alcohol-relatedness as the dependent variable and a single time variable included in each model for illustrative purposes. Using spline functions based on data intervals, a smoothed curve was generated to illustrate the proportion of alcohol-related ambulance contacts by hour of the week and across the study period.23
Danish COVID-19 restrictions were introduced on 11 March 2020, and remained in place until 11 June 2021. We conducted additional analyses to examine the impact of this period on the overall proportion of alcohol-related ambulance contacts. Cubic splines were used to illustrate the weekly proportion of alcohol-related contacts during the study period. Furthermore, a sensitivity analysis was performed, excluding all ambulance contacts that occurred during the national restrictions (March 2020 to June 2021). Since the included variables were either complete or had minimal missing data, no statistical methods were applied to handle missingness. STATA V.18.0 was used for statistical analyses.
Patient and public involvement
No patients or members of the public were involved in the design, conduct, reporting or dissemination plans of our research.
Results
From the 87 820 ambulance contacts recorded between March 2015 and April 2024, an assessed 5433 (6.2%) were considered alcohol-related (table 1). Two-thirds of the alcohol-related ambulance contacts were males (n=3608, 66%), and the proportion of all ambulance contacts related to alcohol among male patients was more than twice the proportion observed in female patients (RP 2.03 (95% CI 1.92 to 2.14)). A quarter of the alcohol-related contacts were aged 55–69 years (n=1365, 25%), but the proportion of ambulance contacts related to alcohol was significantly higher among those aged 15–24 years (n=1083, 17%) compared with other age groups. Alcohol-related contacts were characterised by a relatively higher proportion of requests initiated through 1-1-2 calls (RP 3.79 (95% CI 3.44 to 4.16)), B-level contacts (RP 1.62 (95% CI 1.53 to 1.71)) and contacts terminated on-site (RP 1.88 (95% CI 1.77 to 2.00)).
Table 1. Number of total, non-alcohol-related and alcohol-related ambulance contacts in a sample of 87 820 patients and RP of alcohol-related contacts by characteristics in the Capital Region of Denmark, March 2015 to April 2024.
| Contacts, n (%) | Proportion alcohol-related | ||||
|---|---|---|---|---|---|
| Total | Non-alcohol related | Alcohol-related | % | RP (95% CI) | |
| Total | 87 820 | 82 387 (94) | 5433 (6.2) | ||
| Sex | |||||
| Female | 44 459 (51) | 42 634 (52) | 1825 (34) | 4.1 | 1.00 (ref) |
| Male | 43 358 (49) | 39 750 (48) | 3608 (66) | 8.3 | 2.03 (1.92 to 2.14) |
| Age | |||||
| 15–24 | 6379 (7.3) | 5296 (6.4) | 1083 (20) | 17 | 1.76 (1.62 to 1.91) |
| 25–39 | 10 908 (12) | 9889 (12) | 1019 (19) | 9.3 | 0.97 (0.89 to 1.05) |
| 40–54 | 12 851 (15) | 11 612 (14) | 1239 (23) | 9.6 | 1.00 (ref) |
| 55–69 | 18 532 (21) | 17 167 (21) | 1365 (25) | 7.4 | 0.76 (0.71 to 0.83) |
| 70+ | 39 150 (45) | 38 423 (47) | 727 (13) | 1.9 | 0.19 (0.18 to 0.21) |
| Average age | 61.6 | 62.6 | 46.3 | ||
| Requestor* | |||||
| 1813 | 19 247 (22) | 18 776 (23) | 471 (8.7) | 2.5 | 1.00 (ref) |
| 1-1-2 | 47 810 (54) | 43 380 (53) | 4430 (82) | 9.3 | 3.79 (3.44 to 4.16) |
| Other | 20 763 (24) | 20 231 (25) | 532 (9.8) | 2.6 | 1.05 (0.92 to 1.19) |
| Ambulance response† | |||||
| A-level | 42 227 (48) | 40 251 (49) | 1976 (36) | 4.7 | 1.00 (ref) |
| B-level | 45 593 (52) | 42 136 (51) | 3457 (64) | 7.6 | 1.62 (1.53 to 1.71) |
| Termination of contact | |||||
| Hospital | 74 906 (86) | 70 783 (86) | 4123 (76) | 5.5 | 1.00 (ref) |
| On-site | 12 447 (14) | 11 157 (14) | 1290 (24) | 10 | 1.88 (1.77 to 2.00) |
| Regional area | |||||
| Suburbs and rural areas | 75 188 (86) | 71 349 (87) | 3839 (71) | 5.1 | 1.00 (ref) |
| Distal city centre | 9306 (11) | 8329 (10) | 977 (18) | 11 | 2.06 (1.92 to 2.21) |
| City centre | 2627 (3.0) | 2047 (3) | 580 (11) | 22 | 4.32 (3.96 to 4.72) |
| Weekday | |||||
| Monday | 12 341 (14) | 11 829 (14) | 512 (9.4) | 4.2 | 1.00 (ref) |
| Tuesday | 12 356 (14) | 11 790 (14) | 556 (10) | 4.6 | 1.10 (0.98 to 1.24) |
| Wednesday | 12 629 (14) | 12 078 (15) | 551 (10) | 4.4 | 1.05 (0.93 to 1.19) |
| Thursday | 12 314 (14) | 11 648 (14) | 666 (12) | 5.4 | 1.30 (1.16 to 1.46) |
| Friday | 12 652 (14) | 11 340 (14) | 1312 (24) | 10 | 2.50 (2.26 to 2.77) |
| Saturday | 13 019 (15) | 11 745 (14) | 1274 (23) | 9.8 | 2.36 (2.13 to 2.61) |
| Sunday | 12 509 (14) | 11 957 (15) | 552 (10) | 4.4 | 1.06 (0.94 to 1.20) |
1813: the non-emergency helpline, 1-1-2: the emergency number.
A-level: immediate response with sirens, B-level: response within 25 min.
RP, relative proportion.
A large proportion of the alcohol-related contacts occurred in the suburbs and rural areas (n=3839, 71%), while 18% and 11% occurred in the distal city centre and city centre, respectively (table 1). However, a larger proportion of all ambulance contacts was related to alcohol in the distal city centre (RP 2.06 (95% CI 1.92 to 2.21)) and city centre (RP 4.32 (95% CI 3.96 to 4.72)) compared with the suburbs and rural areas. This trend was also observed across sex, with 27% of ambulance contacts in the city centres being alcohol-related among males and 17% among females (online supplemental figure S1). Similarly, across age groups, the highest proportion of alcohol-related contacts was observed in the city centre, with the highest proportion in patients aged 15–24 years (43%), decreasing with age to 5.7% among patients aged 70 years or older (figure 2).
Figure 2. Proportion of alcohol-related ambulance contacts by location in the Capital Region of Denmark, March 2015 to April 2024, by age groups.
While the peak time for all ambulance contacts occurred during weekdays in the daytime, reflecting a circadian pattern (online supplemental figure S2), alcohol-related contacts were more frequent on Fridays (RP 2.50 (95% CI 2.26 to 2.77)) and Saturdays (RP 2.36 (95% CI 2.13 to 2.61)) compared with Mondays (table 1). Both females and males followed a similar pattern of alcohol intake throughout the week; however, the proportion of alcohol-related contacts remained consistently higher among males compared with females (online supplemental figure S3). Similarly, the proportion of alcohol-related contacts across all age groups peaked during weekend night hours. Individuals aged 15–24 years were characterised by distinct high peaks, reaching 65% (95% CI 0.56% to 0.75%) and 58% (95% CI 0.49% to 0.68%) of contacts being alcohol-related on Saturday and Sunday mornings at 03:00–04:00, respectively. In contrast, older age groups displayed a wider, more homogenous pattern throughout the week (figure 3). Compared with those aged 15–24 years, individuals aged 25–39 years exhibited lower peaks during weekdays, with a notable increase in contacts during the weekend night hours.
Figure 3. Proportion of alcohol-related ambulance contacts and 95% CIs by hour of the week in the Capital Region of Denmark, March 2015 to April 2024, by age groups.
The most prevalent cause of alcohol-related ambulance contacts was an accident (n=2053, 38%), followed by acute alcohol intoxication (n=1418, 26%). Other alcohol-related contacts were due to somatic symptoms (n=890, 16%), psychiatric symptoms (n=626, 12%) and violence (n=234, 4.3%), while 212 contacts (3.9%) were unspecified. A higher proportion of alcohol-related contacts in females compared with males was due to psychiatric symptoms (17% vs 8.7%), while a greater proportion of contacts in males compared with females was attributed to accidents (40% vs 34%) and violence (5.0% vs 2.9%) (online supplemental figure S4). The proportion of alcohol-related contacts resulting from accidents increased with age, reaching its highest level in individuals aged 70 years or older (60%). In contrast, the proportion of contacts related to acute alcohol intoxication was highest among individuals aged 15–24 years (41%) and decreased with age (figure 4).
Figure 4. Cause of alcohol-related contact in the Capital Region of Denmark, March 2015 to April 2024, by age groups. To reach a total of 100% within each age group, the remaining alcohol-related contacts are due to unspecified causes.
Among the alcohol-related contacts attributed to accidents, 1487 (72%) were caused by falls, 383 (19%) resulted from traffic accidents and 183 (8.9%) were caused by other types of accidents. In terms of injury location, 1092 (53%) of the alcohol-related accidents involved injuries to the head, face, neck or back, while 388 (19%) involved injuries to the extremities, and 176 (8.6%) involved injuries to a combination of these regions. In 397 cases (19%), the injuries were located elsewhere or were not adequately described.
New Year’s Eve represented a critical period for prehospital medical services, with a markedly elevated proportion of ambulance contacts related to alcohol. The proportion of alcohol-related ambulance contacts on New Year’s Eve was 2.09 (95% CI 1.58 to 2.76) times greater than on other nights. The increased risk was significantly higher across sex and all age groups, except for patients aged 70 and older (online supplemental table S1). Additionally, a tendency towards a higher proportion of alcohol-related contacts was observed on Fridays and Saturdays following payday, compared with other Fridays and Saturdays (RP=1.08 (95% CI 0.99 to 1.18)). This increased risk was observed among both males and females, as well as within the age groups 15–24, 25–39 and 40–54. However, the association was not statistically significant (online supplemental table S2).
The proportion of alcohol-related contacts remained generally stable during the study period, with slightly lower levels observed during the period with Danish COVID-19 restrictions in 2020 and the first half of 2021 (online supplemental figure S5). Following the phasing out of restrictions, the proportion of alcohol-related contacts returned to levels similar to those observed in the years prior to COVID-19. Excluding contacts occurring during national restrictions, the proportion of alcohol-related contacts was 6.4% (95% CI 6.18% to 6.54) compared with 6.2% (95% CI 6.02% to 6.35).
Discussion
During the study period from March 2015 to April 2024, 6.2% of all ambulance contacts in the Capital Region of Denmark were related to alcohol, with a higher frequency in males compared with females (RP 2.03 (95% CI 1.92 to 2.14)). The proportion of alcohol-related contacts was highest among individuals aged 15–24 years (17%) and decreased progressively with age, reaching 1.9% in the oldest age group (70+ years). Across all age groups, contacts followed a circadian pattern, with the highest proportions occurring during night-time hours, peaking during weekends. The most common causes of contacts were accidents (38%) and acute alcohol intoxication (26%). The proportion of alcohol-related ambulance contacts due to accidents increased significantly with age, while the proportion related to acute intoxication decreased notably, indicating opposing age-related trends. Moreover, minor differences in the cause of contact were observed between females and males.
Previous studies from the UK have reported a higher estimated burden of alcohol-related ambulance contacts compared with the proportion observed in this Danish study. Martin et al estimated that 10% of all ambulance contacts in the Northeast of England were alcohol-related, while Manca et al assessed that 16% of ambulance contacts in Scotland were alcohol-related. However, these studies differ from ours by including not only cases of acute alcohol intoxication but also contacts indirectly related to alcohol, such as those involving alcohol dependency or victims of alcohol-related violence, in their definition of alcohol-related contacts. Additionally, in both studies, ambulance personnel were able to flag alcohol-related ambulance contacts as well as provide detailed descriptions in the free-text fields of the PMR, making the identification of alcohol-related contacts more straightforward compared with this study, which only used free-text fields.12 19
We observed a sex and age difference in alcohol-related ambulance contacts. We found that 66% of the alcohol-related contacts were among male patients, which aligns with the findings of Martin et al and Manca et al, who reported that males accounted for 64% and 62% of alcohol-related contacts, respectively. These findings are consistent with broader health data studies, highlighting the significant health burden alcohol places on men.3 The high proportion of alcohol-related contacts in young adults (17%), relative to the overall population (6.2%), suggests that this age group is disproportionately affected. This likely reflects not only the higher prevalence of risky alcohol consumption commonly associated with adolescence and early adulthood,7 but also the relatively limited range of other causes for ambulance contacts in this age group.
The proportion of alcohol-related contacts followed a circadian pattern, with the largest proportion observed during night-time hours, particularly during weekends. This increase, especially pronounced among younger age groups (for instance, 65% of ambulance contacts were alcohol-related during the early hours of Saturday morning (03:00–04:00), emphasises the strong temporal association between alcohol consumption and specific periods, highlighting the prominence of alcohol culture in nightlife activities. This finding is supported by previous studies of prehospital contacts.12 18 19 Conversely, among older age groups, the proportion of alcohol-related ambulance contacts was more evenly distributed throughout the week, suggesting different drinking patterns and contexts, with alcohol being a less dominant factor in ambulance use compared with younger individuals.
Although a large proportion of alcohol-related contacts occurred in the suburbs (71%), the RP of ambulance contacts being alcohol-related was significantly higher in the distal city centre and the city centre. Studies have shown that higher densities of both off-premise and on-premise alcohol outlets are associated with increased rates of unintentional injuries and assaults.24 25 This suggests that the concentration of alcohol outlets in city centres has severe consequences, leading to a higher demand for emergency services.
The most prevalent cause of alcohol-related ambulance contacts was accidents (38%), followed by acute alcohol intoxication (26%). Older age groups were more likely to experience accidents, while younger age groups were more affected by acute intoxication, indicating that the nature of alcohol-related ambulance contacts shifts with age. Older adults are more vulnerable to the health effects of alcohol use due to age-related health factors, such as chronic disease, impaired muscle strength and balance, and interaction with prescribed medication.26 27 Therefore, the higher proportion of alcohol-related accidents among older adults is not surprising, even though their alcohol consumption may not have been as high as that of younger people.9 Similarly, the higher proportion of acute alcohol intoxication among young people is consistent with broader trends, as young people in Europe tend to binge drink more often.5
When excluding ambulance contacts that occurred during the period of Danish COVID-19 restrictions, we observed no major differences in the proportion of alcohol-related contacts. This aligns with Bruun et al,18 who also found no significant differences when excluding the period of national COVID-19 restrictions. Therefore, we believe that including ambulance contacts from this period does not impact our study’s generalisability.
Strengths and limitations
A key strength of this study was the use of data collected from a large, representative sample of ambulance contacts involving individuals aged 15 years or older between 2015 and 2024 in the Capital Region of Denmark. Although the manual coding of free-text fields from PMRs is resource-intensive, it enabled us to analyse detailed information on alcohol intoxication and its associated medical causes, information that is not documented elsewhere.
Compared to Bruun et al, we improved the specificity of the search string by only including exact matches of the Danish keywords (94% vs 85%). This approach effectively limited the number of false positive identifications by preventing Danish keywords from being recognised as embedded words. Despite this improvement in specificity, we achieved a slightly lower sensitivity of the search string (95% vs 98%). This reduction in sensitivity is likely due to the inclusion of older age groups, which may be described differently from younger age groups, using other phrases regarding alcohol intake and intoxication. However, the high level of sensitivity indicates that any potential underestimation of the proportion of alcohol-related contacts is minimal.
Despite the high prevalence observed, our findings may not fully capture the burden of alcohol-related ambulance contacts, as we relied on free texts from the PMRs. In these records, the ambulance personnel primarily focus on recording clinically relevant information about the acute incident, rather than explicitly noting whether the patient is intoxicated by alcohol or not. This may have limited our ability to identify all alcohol-related ambulance contacts, as cases without explicit mention of alcohol intoxication or intake may have been overlooked. However, this is unlikely to have affected contacts where alcohol intoxication was the primary cause for the ambulance call. Secondary or less direct effects of alcohol, such as victims of alcohol-related violence or assaults, may have been missed if it was not explicitly stated that the victims themselves were intoxicated. Additionally, the exclusion of cases where information on age was missing (3.7% of all ambulance contacts) may have led to an underestimation of alcohol-related ambulance contacts, as many contacts without personal identification numbers have been found to be alcohol-related.28
Finally, despite taking precautions to test inter-rater agreement for the main variables, alcohol intoxication and primary cause of contact, we acknowledge the subjectivity and potential bias associated with manual coding. Furthermore, the information on the primary cause of contact is influenced by the level of detail provided in the PMR free-text field, which varied across patients.
Conclusion and implications
This study found that 6.2% of all urgent ambulance contacts in the Capital Region of Denmark from 2015 to 2024 were alcohol-related. Most alcohol-related contacts occurred during night-time hours, with acute alcohol intoxication being more prevalent among younger individuals, while accidents were more common in older age groups. These ambulance contacts place a considerable burden on the healthcare system, using valuable prehospital resources. Given the relatively high prevalence of callouts for alcohol-affected people, consideration should be given to targeted preventive measures aimed at reducing alcohol-related harms and to prioritising the efficient allocation of prehospital resources.
Supplementary material
Acknowledgements
The authors would like to thank Jens Morten Haugård and the Emergency Medical Services, Capital Region of Denmark, for providing access to data and for sharing valuable insights into data and procedures.
Footnotes
Funding: This work was supported by the Swedish foundation Stiftelsen Ansvar för Framtiden (ID 3110625). The funder had no role in the study design, data collection, analysis, interpretation, writing or decision to publish.
Provenance and peer review: Not commissioned; externally peer reviewed.
Patient consent for publication: Not applicable.
Ethics approval: This study involves human participants, but ethical approval was not required as the project was register-based. The use of data was registered with and approved by the Danish Data Protection Agency and the Capital Region of Denmark. All data protection and handling requirements were fulfilled. Informed consent of individual patients was not required in accordance with the Research Ethics Committee in the Capital Region of Denmark, the Danish Data Protection Agency or the Copenhagen EMS.
Patient and public involvement: Patients and/or the public were not involved in the design, conduct, reporting or dissemination plans of this research.
Data availability statement
Data are available upon reasonable request.
References
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
Data are available upon reasonable request.