Serious conditions among patients with non-specific chief complaints in the pre-hospital setting: a retrospective cohort study

Emergency Medical Services (EMS) play an important role in assessing, initiating treatment and transporting patients to the Emergency Department (ED). Patients present to the EMS with a primary symptom, i.e. chief complaint. Chief complaints without specific components linked to anatomical, clear physiological and pathophysiological systems are considered as non-specific chief complaints. Patients are assessed based on vital signs and patient history according to local EMS guidelines [1]. The number of patients presenting to the EMS with NSCs is unknown, as is the prevalence of serious conditions in this group. Although, non-specific chief complaints (NSCs) have been studied in the pre-hospital setting [2, 3], it has been shown, however, that up to one in every five patients in the ED has a NSC [4]. Previous studies have shown that half of these patients are suffering from a serious underlying condition [4, 5]. Patients presenting with NSCs often present as “affected general health condition” or “decreased general condition,” “general malaise,” “sense of illness” or “just being unable to cope with usual daily activities,” and often present with normal vital signs [6‐8]. Patients presenting with NSCs are often elderly, and as many as half of these patients suffer from an acute condition [9]. The elderly presenting with NSCs are often under-triaged [9], despite having the highest in-hospital mortality rates of all patients with non-trauma/non-surgical chief complaints in the ED [10]. Therefore, the primary aim of the current study was to establish the prevalence of serious conditions among patients presenting to EMS with NSCs. The secondary aim was to determine the mortality rates for patients presenting with NSCs.

A total of 3780 patients with NSCs were included in the current study (Fig. 1). The median age was 77 years of age. Triage levels were: 60.8% (n = 2027) were green according to RETTS and 76.3% (n = 2845) had low clinical risk according to NEWS. The overall admission rate to in-hospital care was 67.6% (n = 2557) with a median in-hospital LOS of 5 days (range 0–72 days). The median CCI score was 1 point (range 0–9 points) (Table 1).

Patients with serious conditions presented with higher triage levels according to both the RETTS and NEWS as compared to patients with no serious conditions (Table 1).

Overall in-hospital mortality was 4.2% (n = 160), 24 h mortality 1.1% (n = 42), and 30-day mortality was 9.8% (n = 372). In the group with serious conditions, in-hospital mortality was 10.1% (n = 135) (OR 6.8, CI 95%, 4.1–11.3), 24 h mortality 1.9% (n = 26), and 30-day mortality was 20.2% (n = 269) (OR 3.1, CI 95%, 2.3–4.0). In the group with no serious conditions the corresponding in-hospital mortality was 1.0% (n = 25), 24 h mortality 0.7% (n = 16), and 30 day mortality 4.2% (n = 103) (Tables 1 and 2).

Stratified models of triage levels are presented in Table 3. In RETTS green (n = 2027) and NEWS low clinical risk (n = 2845), a serious condition was present in 23.9% (n = 484) and 28.3% (n = 804) of the patients respectively. Thirty day mortality was 13.0% (n = 63) (OR 5.0, CI 95%, 3.2–7.9) and 14.1% (n = 113) (OR 3.7, CI 95%, 2.7–5.2) respectively in the group with serious conditions.

The most common discharge diagnosis for patients with serious conditions was infectious disease (31.0%, n = 413), followed by cardiovascular disease (26.4%, n = 352) (Table 4).

The results show that more than one-third of patients with NSCs had a serious condition. Mortality rates were almost four times higher in the group with serious conditions as compared to those without serious conditions.

More than one-third of the patients presenting with NSCs in the current study had a serious condition as compared with approximately 60% in prior studies in ED settings [5, 19, 20]. It is however, surprising that the prevalence of serious conditions in the current study was lower compared to studies of patients presenting to the ED with NSCs without concern to mode of arrival [5, 19, 20]. This is in conflict with, patients arriving to the ED by ambulance are in general sicker than those who “walk in” [21]. The definition of serious conditions in the current study may partly explain the difference since it may select for a sicker population. This lower prevalence might also be explained in part by the assessments made by the EMS personnel, if the patient is perceived as more ill the assessment by the EMS may tend to use a more specific complaint. Despite these differences, the prevalence of serious conditions among patients with NSCs is high and should be taken into consideration in clinical practice. With that in mind, the retrospective triage scores according to RETTS and NEWS were as expected associated with the prevalence of serious conditions when patients were assessed to a higher triage level. Nevertheless, the majority of patients with NSCs had low triage levels. Interestingly, patients with low triage scores had nearly as often prevalent serious conditions comparable to the current studies overall population. This implies that triage levels are an insufficient tool with which to identify serious conditions. We suggest that the reason for this is likely to be that triage levels are based on vital signs. Patients with NSCs were in general elderly, which is consistent with prior research [2, 5, 10, 19, 22]. Almost half the patients in the current study were over 80 years old, and the majority presented with vital signs within the normal range. The presence of normal vital signs can likely be explained by the physiological changes in older adults, which tend to reduce the ability of organ systems to adapt to physiological changes, leading to an absence of deranged vital signs [7, 19, 23]. How to identify serious conditions other than by triage level requires further investigation.

Mortality rates were higher in the group with serious conditions as compared to those with no serious conditions, among patients presenting with NSCs to the EMS. The mortality rate in the current study was slightly higher than the mortality rate in the study by Nemec et al. [5], but not as high as the rates reported by Säfwenberg et al. [10]. The higher mortality rate in comparison to the current study could be discussed, since Säfwenberg et al. [10] only studied patients with one of the NSCs, i.e. general disability, which may be selecting for a sicker population. Both overall in-hospital mortality rates and mortality rates for patients with serious conditions were comparable with those in previous studies [2, 10, 24]. Wallgren et al. [25] reported in-hospital mortality rates as high as one third of the patients with sepsis and a presenting complaint of decreased general condition (an NSC), while non-septic patients with decreased general condition had one tenth of that mortality. That one in every five patients in the current study presenting with NSCs and having a serious condition died within 30 days underscores the need to change our management of this patient population. In conclusion, and based on the current results, triage systems based on vital signs appear to be insufficient both in identifying serious conditions and in predicting mortality among patients with non-specific chief complaints.

The most common discharge diagnosis was an infectious disease, such as pneumonia or urinary tract infection. The infectious diseases were followed by cardiovascular and neurological diseases. The clinical picture at the index EMS assessment can be non-specific and more sophisticated diagnostic tools may be required to establish the diagnosis.

Idenitfication of patients with serious conditions among those with NSC in the prehospital setting remains a challenge. Point of care tests of biomarkers may aid in the identification of single diagnosis time critical conditions e.g. myocardial infarctions and sepsis in this group, and may be of some use. However, this will likely leave a larger proportion of the patients with NSC remaining as undifferentiated. In this case we believe that two important approaches need to be considered. One is the advancement of experienced clinicians in the field with the skill and knowledge to make clinical decisions based on the complex background of individual patients. The other is on mutual terms to include the patients’ own wish for further care, i.e. a patient-centered approach. Also this requires experienced clinicians in field.

The results show that more than one in three of the patients presenting to the EMS with NSC have a serious condition. The presence of serious conditions is associated with both a tenfold increase in-hospital mortality and a five times higher 30-day mortality compared to patients without serious conditions. Low triage scores are common in patients presenting to EMS with NSCs despite underlying serious conditions and high mortality. Hence, vital-sign-based triage systems appear to be insufficient when attempting to identify patients at high risk of having a serious condition and of dying among those presenting to EMS with non-specific chief complaints.