In total, 6,465 titles and abstracts were screened, and 6,283 were deemed irrelevant to the topic area. Of the remaining 182 papers, 14 met the inclusion criteria (see Fig. 1 for PRISMA flow diagram [10]).

PRISMA flow diagram showing the inclusion and exclusion process. The figure shows the inclusion process and reasons for exclusion of identified records

Four of the included studies were conducted in Australia [11,12,13,14], and two were conducted in both Canada [15, 16] and Sweden [17, 18]. One study each was conducted in Haiti [19], Norway [20], Switzerland [21], Belgium [22], Indonesia [23], and the UK [24]. The publication dates of the included studies spanned from 1993 to 2022, with all but three published in the last 10 years. Data were collected via surveys in seven of the studies and from databases in six; the remaining studies used both methods. The study and patient characteristics of the included studies are provided in Additional file 2.

An overview of the patient characteristics revealed that half of the studies included only adult patients. Adult patients were also most prevalent in the remaining studies [13,14,15, 19, 20, 22, 23]. The proportion of females ranged from 46 to 66% across the studies. The sample sizes were relatively large and ranged from 332 to 10,941,286. Differences between studies in terms of the amount and level of detail of the presenting conditions precluded a summary of these data. Four categories of information were commonly reported across the studies: 1) where patients physically arrived from, 2) how they were transported, 3) who referred them, and 4) whether medical care or advice was sought prior to visiting an ED. In all the categories, the evidence was limited by the small number of papers and by the sparseness of the data reported within them.

Knowing where patients physically arrived from contributes to understanding where demand most often begins. Only one study reported data that provided a full picture of where patients arrived from before visiting an ED [19] (Additional file 3). Although this Haitian study reflects a different social and healthcare context than that observed in Europe and North America, it shows that the highest proportion of patients (64%) arrived directly from their homes, with very few patients arriving from other places. This may also be the case in other countries, but published evidence is lacking. Three additional studies in Australia, Switzerland, and the UK reported low presentations of patients from nursing homes, ranging from 0.9% to 2% [11, 21, 24]. Additionally, one UK study with two data collection sites reported that 4.3% to 4.8% of patients were ‘referred’ from an office, shop, or workplace, and we assumed that they arrived at the ED directly from this place [24]. No further studies were found that directly addressed this topic.

The mode of arrival or method of transport to an ED provides information about emergency service utilization as part of the patient journey. Ten studies reported this type of data [12,13,14,15, 17,18,19,20, 22, 23]. The proportion of patients who arrived by ambulance ranged from 8 to 43% (across 9 studies), with the majority arriving by public or private transport (Additional file 4). Very few patients arrived via police transport (0.5% to 0.9% across two studies). The mode of arrival was described as ‘self-presented’ or ‘walked-in’ in three studies [14, 20, 24], with proportions ranging between 69 and 91%; however, referral status or more specific means of transport were not reported. These data provide limited insight into the pathway of care prior to an ED visit for this group but may indirectly indicate the patients’ acuity.

The referral patterns indicate the last contact point before visiting an ED. Six studies (with seven data collection sites) variously reported on referrals through telephone services [17, 18, 22], urgent care centers [17, 20], outpatient clinics [17, 20], out-of-hours doctors [24], general practices [12, 17, 18, 22, 24], and the police. Five of these studies (with six data collection sites) also reported self-referral to the ED [12, 17, 18, 22, 24], and all the studies showed that this was the most prevalent mode of referral (ranging from 34 to 89%). The second most frequent points of referral were PCPs (ranging from 13 to 38% across four studies with five data collection sites), urgent care centers (ranging from 7 to 35% across two studies), and telephone services (0.5% to 11% across three studies) (Additional file 5).

Similar to the studies that reported referral rates, six studies specifically reported on the proportions of patients seeking medical care or advice before visiting an ED [12, 17, 18, 22, 24] (Fig. 2). However, it was sometimes unclear whether multiple sources of advice were sought for each patient and, if so, in what order and when. A relatively high proportion (up to 56%) of the patients seeking medical care did so through their PCP (physically or via a telephone call) or through another health professional rather than seeking advice using other options available (e.g., telephone or internet health service). The percentage of patients who went directly to the ED without seeking advice ranged from 39% (in Canada) to 89% (in the UK).

The proportion of patients who sought medical care or advice before visiting an ED. This figure provides an overview of the rates of direct referral to the emergency department (ED) and attempted care and advice provided before visiting an ED