Patients Presenting to the Emergency Department With Non-specific Complaints: The Basel Non-specific Complaints (BANC) Study


  • Marek Nemec MD,

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    • *

      Equal contribution of the first and second authors.

  • Michael T. Koller MD, MSc,

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    • *

      Equal contribution of the first and second authors.

  • Christian H. Nickel MD,

    1. From the Department of Emergency Medicine (MN, CHN, SM, CW, CK, GL, RB), Basel Institute for Clinical Epidemiology and Biostatistics (MTK), the Division of Infectious Diseases (GL), and the Medical Outpatient Department (MTK, CK), University Hospital, Basel, Switzerland.
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  • Silke Maile MD,

    1. From the Department of Emergency Medicine (MN, CHN, SM, CW, CK, GL, RB), Basel Institute for Clinical Epidemiology and Biostatistics (MTK), the Division of Infectious Diseases (GL), and the Medical Outpatient Department (MTK, CK), University Hospital, Basel, Switzerland.
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  • Clemens Winterhalder MD,

    1. From the Department of Emergency Medicine (MN, CHN, SM, CW, CK, GL, RB), Basel Institute for Clinical Epidemiology and Biostatistics (MTK), the Division of Infectious Diseases (GL), and the Medical Outpatient Department (MTK, CK), University Hospital, Basel, Switzerland.
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  • Christine Karrer MD,

    1. From the Department of Emergency Medicine (MN, CHN, SM, CW, CK, GL, RB), Basel Institute for Clinical Epidemiology and Biostatistics (MTK), the Division of Infectious Diseases (GL), and the Medical Outpatient Department (MTK, CK), University Hospital, Basel, Switzerland.
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  • Gerd Laifer MD,

    1. From the Department of Emergency Medicine (MN, CHN, SM, CW, CK, GL, RB), Basel Institute for Clinical Epidemiology and Biostatistics (MTK), the Division of Infectious Diseases (GL), and the Medical Outpatient Department (MTK, CK), University Hospital, Basel, Switzerland.
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  • Roland Bingisser MD, FCCP

    1. From the Department of Emergency Medicine (MN, CHN, SM, CW, CK, GL, RB), Basel Institute for Clinical Epidemiology and Biostatistics (MTK), the Division of Infectious Diseases (GL), and the Medical Outpatient Department (MTK, CK), University Hospital, Basel, Switzerland.
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Address for correspondence and reprints: Roland Bingisser, MD, FCCP; e-mail:


Objectives:  Patient management in emergency departments (EDs) is often based on management protocols developed for specific complaints like dyspnea, chest pain, or syncope. To the best of our knowledge, to date no protocols exist for patients with nonspecific complaints (NSCs) such as “weakness,”“dizziness,” or “feeling unwell.” The objectives of this study were to provide a framework for research and a description of patients with NSCs presenting to EDs.

Methods:  Nonspecific complaints were defined as the entity of complaints not part of the set of specific complaints for which evidence-based management protocols for emergency physicians (EPs) exist. “Serious conditions” were defined as potentially life-threatening or those requiring early intervention to prevent health status deterioration. During a 6-month period, all adult nontrauma patients with an Emergency Severity Index (ESI) of 2 or 3 were prospectively enrolled, and serious conditions were identified within a 30-day period.

Results:  The authors screened 18,261 patients for inclusion. A total of 218 of 1,611 (13.5%) nontrauma ESI 2 and 3 patients presented with NSCs. Median age was 82 years (interquartile range [IQR] = 72 to 87), and 24 of 218 (11%) were nursing home inhabitants. A median of 4 (IQR = 3 to 5) comorbidities were recorded, most often chronic hypertension, coronary artery disease, and dementia. During the 30-day follow-up period a serious condition was diagnosed in 128 of 218 patients (59%). The 30-day mortality rate was 6%.

Conclusions:  Patients with NSC presenting to the ED are at high risk of suffering from serious conditions. Sensitive risk stratification tools are needed to identify patients with potentially adverse health outcomes.

ACADEMIC EMERGENCY MEDICINE 2010; 17:284–292 © 2010 by the Society for Academic Emergency Medicine

Patients frequently present to emergency departments (EDs) with non-specific complaints (NSCs). The outcomes for these persons are poorly defined. Affected individuals often complain of “not feeling well,”“feeling weak,”“being tired,” feeling “dizzy,” or simply being unable to cope with usual daily activities.1 Some patients may fail to recall why they were brought to the ED. During the care of patients with NSCs, emergency physicians (EPs) face a broad differential diagnosis, ranging from insufficient home care to acute, life-threatening conditions.2 Patients with NSCs are among the most challenging to EPs.3 Moreover, the clinical picture is often blurred by factors such as comorbidities, polypharmacy, altered mental status, and failure of an acute care or extended care facility to communicate the reason for transfer, among others.

Vanapee et al.4 demonstrated that up to 20% of older individuals presenting to the ED have no specific complaints. Another study found that 50% of older individuals without specific complaints suffered from an acute medical problem.5 The ED geriatric population is a particularly high-risk group for adverse outcomes (e.g. functional decline, dependence, and death).6 The needs and chief complaints of these patients with NSCs must be better defined, and the development of efficient and safe decision and management strategies is essential.3,5,7

Patients in emergency medicine can often be managed by the use of diagnostic and treatment protocols based on presenting chief complaints, such as acute chest pain, dyspnea, or flank pain.8–13 No comparable management protocols have been published for NSCs, most likely due to a lack of a consistent definition for NSC and the paucity of research regarding differential diagnosis and efficient work-up strategies in this population.14 Uncertainty often accompanies the diagnostic process for these patients, with potentially duplicative confirmatory testing being ordered for the exclusion of an underlying “serious condition.”4,7 This may result in ineffective or suboptimal triage of these patients, delayed ED throughput, and inadequate postdischarge outpatient referrals.15,16

The ultimate goal of the Basel Non-specific Complaints (BANC) study is to prospectively identify a set of risk factors (“red flags”) predictive of a serious condition in ED patients with NSCs. The primary goal of this study is to provide a stringent definition of NSC serving both clinical practice and scientific objectives. For clinical practice, a coherent definition for NSCs could help to enable a more structured and proactive approach to patient management and, ultimately, to implement diagnostic algorithms or predictive scores.17 For scientific objectives, the definition may facilitate research that translates into reproducible results.5,18 The purpose of the present study is to provide a framework for research on patients with NSCs, to describe the characteristics of this population, and to determine the presence of serious conditions that are likely to underlie NSCs.


Study Design

The BANC study is a delayed type cross-sectional diagnostic study. A prospective 30-day follow-up was implemented to identify, ascertain, and specify underlying conditions that most likely have lead to NSC.19 The study protocol was approved by the local ethics committee.

Study Setting and Population

The study took place in the ED of the University Hospital of Basel, Basel, Switzerland. The hospital is a 700-bed primary and tertiary care university hospital, and the ED sees over 41,000 patients per year with a typical ED case mix. All patients evaluated in the ED from May 24, 2007, until November 13, 2007, were consecutively enrolled to obtain a sample of the source population of ED self-referred and referred patients with NSCs.

All adult nontrauma patients with an Emergency Severity Index (ESI) of 2 or 320 were screened for inclusion (Figures 1 and 2). Patients with an ESI of 4 or 5 were excluded because their resource utilization is low, by definition. Furthermore, for patients with an ESI 4 or ESI 5, a comprehensive work-up is usually not performed because a working diagnosis can be accurately generated in most cases. Patients with specific complaints (such as chest pain) or a clinical presentation suggestive of a working diagnosis that could be managed using evidence-based management protocols for ED physician use13,21 were excluded. In the case of such exclusion, physicians were asked to name the “specific complaint” or “working diagnosis,” together with the corresponding management protocol21 they applied (Figure 1). Any patients presenting with recent external laboratory results or specific electrocardiogram (ECG) changes on admission (e.g., ST-segment elevation myocardial infarction) were not eligible. Similarly, patients with known terminal medical conditions (e.g., end-stage cancer) who were admitted to the ED and were likely to die within the next 30 days were not eligible. Patients were excluded if they were hemodynamically unstable or if the vital signs were markedly outside the normal range (systolic blood pressure < 90 mm Hg, heart rate > 120 beats/min, temperature > 38.4 or < 35.6°C, respiratory rate > 30 breaths/min), as management protocols exist for this patient group. In addition, all patients referred from other hospitals were excluded.

Figure 1.

 Identification of patients with NSCs in the BANC study. ECG = electrocardiogram; ESI = Emergency Severity Index; GCS = Glasgow Coma Scale; GI = gastrointestinal; NSCs = nonspecific complaints.

Figure 2.

 Study flow of the BANC study. BANC = Basel Non-specific Complaints; ESI = Emergency Severity Index.

Study Protocol

Definition of NSCs.  The classification of “non-specific” complaints implies a subjective judgment on the part of the EP. Such judgment depends on physician-related factors such as clinical experience and skills and on weighing the different complaints that may guide further assessment. Patient-related factors include the ability to verbalize complaints, the patient’s cognitive state, or both. A definition of NSC aims to narrow subjectivity in the classification of patients and, as a consequence, to facilitate structured and proactive patient management.

A specific chief complaint usually provides key information that allows the generation of a working diagnosis and the initiation of a predefined diagnostic and/or treatment protocol. Specific complaints are well-recognized as such in the literature, and diagnostic protocols are often applied.22,23

In contrast to specific complaints, we defined NSCs as all complaints that are not part of the set of specific complaints or signs or where an initial working diagnosis cannot be definitively established. It is necessary to define NSCs as the remainder, after exclusion of specific complaints, because an active definition would require an almost endless enumeration of possible NSCs. Such a long and complicated definition would likely exclude certain NSC patients because their symptoms failed to exactly match the predefined list. We use the term “working diagnosis” in the context of our NSC definition for situations in which patients present with NSCs, but a serious diagnosis is likely, given the facts and findings at the time of presentation. An example of such a situation is a patient presenting with a chief complaint of weakness, but who has an anemic pallor. Such pallor could be due to blood loss from a colonic malignancy, a myelodysplastic syndrome, or a host of other possibilities. Figure 1 summarizes this definition in a procedural way.

Non-specific Complaints: Defining the Endpoint of Serious Condition.  Due to the broad spectrum of possible diseases underlying a presentation with NSCs, a narrow, disease-specific endpoint definition for the term “serious condition” is not suitable. In patients with NSCs, EPs must be concerned about the task of case identification, i.e., to distinguish serious from nonserious outcomes or conditions. Thus, we define a serious condition as any potentially life-threatening condition (as exemplified by a myocardial infarction) or any condition that requires an early intervention to prevent health status deterioration leading to possible morbidity, disability, or death (as exemplified by severe hyponatremia). Obviously, the natural course of an underlying serious condition according to this definition should not be awaited. By definition, we scored any death occurring within 30 days of the initial ED presentation as being due to a serious condition, even in cases for which the exact serious condition could not be definitively identified.

Our definition of a serious condition, therefore, covers a comprehensive list (see Data Supplement S1, available as supporting information in the online version of this paper), which was defined a priori, and further refined using a modified Delphi technique during three pilot studies, where experience on serious conditions accumulated. The association of an NSC and a potential serious condition is particularly likely if a close temporal relationship exists between the development of the NSC and outcome detection. This reasoning underlies the choice to define the maximum time lag between patient presentation with NSCs and determination of a serious condition to be limited to 30 days.

ED resident physicians received prestudy training with a lecture and on-site training on how to correctly apply the BANC protocol. A checklist for the inclusion procedure was continually displayed in a prominent location within our ED. All potentially eligible patients were then prospectively screened for enrollment. Screening started with ESI triage and assessment of vital signs by certified ED triage nurses, followed by history-taking, physical examination, and provisional ECG reading by ED resident physicians. Laboratory or imaging results were not available at the moment of screening. To survey the BANC inclusion procedure, all included patients were reviewed by the BANC expert panel physicians according to inclusion and exclusion criteria before the outcome ascertainment, which took place after termination of the 30-day follow-up period.


The following patient data were obtained during ED evaluation and registered on the patient’s case report form: demographic baseline data, ESI score, complaints, vital signs, Glasgow Coma Scale score, medical history, physical examination, and an ECG, which was obtained for all patients. ECGs were provisionally read by the ED resident physician and confirmed by an attending physician. ECGs were formally categorized and recorded (new ST-segment elevation, left bundle branch block, atrial fibrillation, and other abnormalities). Information about activities of daily living according to the Katz index,13,24 recent falls or decline of activities, hospitalizations during the previous year, body mass index and weight loss, consumption of alcoholic beverages, and cognition25 were obtained by bedside patient interviews. Several additional variables, including a complete list of comorbidities26 and use of medication, were gathered from initial physician reports. Part of the data (such as lab values for all patients) was obtained from the hospital electronic medical record system, linked to laboratory, radiology, and cardiology data. BANC study case report forms were filled out either by ED residents or by study physicians. Patients received a work-up and were treated at the discretion of the responsible EP.

Patient Follow-up and Outcome Ascertainment.  We obtained written 30-day follow-up data from the patients` primary care physicians and hospital discharge reports for all hospitalized patients. We obtained interim hospital reports if hospitalization outlasted the 30-day period. Two physicians certified in internal medicine (outcome assessors) and blinded to the patients’ baseline data reviewed all final reports. The main outcome of interest was the occurrence of a serious condition during the 30-day follow-up. In addition, we subclassified all outcomes according to specific groups. An “acute new condition” was defined as a newly diagnosed disease (e.g., pneumonia). A “deterioration of a chronic condition” was defined as the deterioration of a preexisting disease, ultimately leading to further medication or other intervention (e.g., worsening of chronic heart failure). An “acute event in a chronic condition” was defined as an acute unexpected incident or complication in a preexisting condition (e.g., pulmonary embolism in a patient with known cancer; Table 1).

Table 1. 
Results of the 30-day Follow-up of the BANC Study Population (n = 218)
 Nonserious condition (n = 90), n (%)Serious condition (n = 128), n (%)p-value
  1. *Not available.

Acute new condition14 (16)77 (60)
(lethal = 7)
Deterioration of chronic condition53 (59)9 (7)
(lethal = 2)
Acute event in a chronic condition
 In the course of natural-history10 (11)20 (16)
(lethal = 3)
 Therapy-induced3 (3)22 (17)
(lethal = 0)
 Functional disorder10 (11)0 (0)*

If symptoms were thought to be iatrogenic or caused by well-known medication side effects, we subclassified them as “iatrogenic or therapy-induced,” irrespective of whether treatment was initiated or discontinued by either the physician or the patient. Finally, if no somatic disease explained the patient’s NSC after discharge and complete follow-up, the classification “nonorganic or functional” was chosen.

At regular intervals, the outcome assessors reviewed all patient records to establish a final diagnosis according to the 10th International Classification of Diseases and Related Health Problems (ICD-10). According to these guidelines, “main condition” was chosen as the one that was most closely related to the patient’s initial presentation, receiving the highest amount of resources for treatment. If no diagnosis could be made, the main symptom or abnormal finding was chosen to be “main condition,” using a descriptive diagnosis, such as described in chapter R of ICD-10.

In 15 cases, the judgment of the two outcome assessors disagreed. In these cases, the patients’ records were reviewed and consensus sought by the BANC expert panel. The expert panel consisted of two physicians board-certified in internal medicine and also certified in emergency medicine, with at least 10 years of experience.

Data Analysis

Descriptive analyses were performed to summarize the baseline characteristics of the study population and to describe disease manifestations underlying the serious conditions. We used univariate logistic regression to assess the association of a number of baseline risk predictors, such as patient complaints and comorbid factors, with the outcome of serious condition. We used R Version 2.9.0 for data analysis (R Foundation for Statistical Computing, Vienna, Austria).


During the recruitment period, a total of 18,261 patients were screened for inclusion. The majority of patients were not eligible, as their problem was primarily trauma-related or because they fell into the ESI categories 1, 4, or 5 (Figure 2). The second most frequent reason for nonenrollment was that patients presented with specific complaints or that EPs could establish a working diagnosis. This left 1,611 nontrauma patients with an ESI of 2 or 3. During case reviews, the BANC expert panel revoked the initial inclusion of 46 patients (Figure 2) due to violation of inclusion or exclusion criteria. The final study population thus consisted of 218 patients with NSC, or 13.5% of the 1,611 nontrauma, ESI 2 or 3 patients.

The median age was 82 years with an interquartile range (IQR) from 72 to 87 years. The youngest patient was 35 years, the oldest was 102 years old, and 69% of the patients were females. Most patients lived at home and required various degrees of help. Eleven percent of patients were nursing home inhabitants (Table 2). Eighteen percent of the patients were discharged after the initial ED presentation, 46% were transferred to a medical or a geriatric ward, 32% were transferred to a geriatric community hospital, and 4% were admitted to the in-house intensive care unit or died before referral.

Table 2. 
Baseline Demographic Characteristics of the BANC Population (n = 218)
CharacteristicSummary Distribution
  1. Values are n (%) unless otherwise indicated.

  2. ESI = Emergency Severity Index; IQR = interquartile range.

Age, median (IQR) [years]81 (72–87)
Male subjects67 (31)
ESI score
 3201 (92)
 217 (8)
Mode of patient referral
 Self-referral23 (11)
 Family members/neighbors27 (12)
 Family physician or specialist91 (42)
 Ambulance76 (35)
Living situation
 Home, independent53 (24)
 Home, help from family/neighbors64 (29)
 Home, professional help needed78 (36)
 Nursing home23 (11)
Hospitalizations during previous year
 None89 (41)
 1–30 days87 (40)
 More than 30 days42 (19)
 Number of comorbidities, median (IQR)4 (3–5)
 Charlson Index,26 median (IQR)2 (1–3)
 Number of concomitant drugs used, median (IQR)5 (3–8)

Patients expressed a median of 4 (IQR = 3–5) complaints (Figure 3). The most frequent NSCs were “generalized weakness,”“feeling exhausted,” and “recent falls.” The prevalence of the patient complaints and the association with serious condition is illustrated in Figure 4. Gait disturbance and lack of appetite were significant predictors of a serious condition.

Figure 3.

 Multiple complaints, drugs, and co-morbidities in the BANC population. BANC = Basel Non-specific Complaints.

Figure 4.

 Absolute numbers of serious conditions, according to patient complaints in the BANC population. One patient may present with several complaints (see Figure 3). BANC = Basel Non-specific Complaints.

The burden of comorbidity and the number of concomitant drugs used were considerable in the BANC study population. A median of 4 (IQR = 3 to 5) comorbidities were recorded, most often chronic hypertension, coronary artery disease, and dementia (Figures 3 and 5). As a result, the number of concomitantly prescribed drugs accrued to over a dozen (Figure 3). Chronic hypertension and falls were significant predictors of a serious condition.

Figure 5.

 Absolute numbers of serious conditions according to different comorbid illness in the BANC population. One patient may present with several comorbid illness (see Figure 3). BANC = Basel Non-specific Complaints; COPD = chronic obstructive pulmonary disease.

During the 30-day follow-up, we found a serious condition in 128 of the 218 patients (59%). Twelve serious conditions were attributable to death during follow-up (9%, Table 1). We grouped the main conditions according to the ICD-10 disease classification and to the presence or absence of a serious condition (Figure 6). Main conditions were most often classified as circulatory; genitourinary; and endocrine, nutritional, or metabolic. Less prevalent were mental and behavioral disorders. Endocrine/nutritional/metabolic diseases were almost exclusively serious. Although less prevalent, the pattern was similar for the respiratory system, cancer, the digestive system, and external causes. Nonserious conditions (Figure 6) were particularly common in mental/behavioral, nonclassified, and nervous system disorders. In the circulatory system, serious and nonserious conditions were equally distributed.

Figure 6.

 Relative frequencies of serious condition in mutually exclusive disease categories or organ systems. The figure presents point estimates with 95% confidence intervals.

The vast majority of acute new conditions were judged to be serious (85%, 77/91). In contrast, only nine of 62 deteriorations of chronic conditions were classified as serious (15%). Acute events in chronic conditions were seen in 56 patients (26%), and around half were judged to be therapy-induced. Most of these (77%) were categorized as serious (Table 1).

Sixty-seven percent of all final diagnoses were made during initial ED-based testing. The remainder were diagnosed during follow-up. In 15 patients, either frailty or “no somatic disorder” was identified during follow-up. Fourteen infections, 13 psychiatric disorders, 11 cardiovascular disorders, seven renal disorders, six endocrine disorders, three neurologic disorders, and three miscellaneous conditions including one tumor were diagnosed post ED evaluation.


In this study, we provide a framework for research on patients with NSCs presenting to EDs. The objective of this study was to propose feasible and operational definitions for the NSC population together with a clinically useful outcome definition. Moreover, we describe the demographics and clinical characteristics of these patients together with the range of conditions judged to be serious or nonserious.

The characteristic of ED patients presenting with NSC is, that among a multiplicity of somatic, mental, and social symptoms or complaints, none of the well-described “chief complaints” are present to guide the patient evaluation. The key to efficient management of patients with any complaint is the ability to reliably predict who will fare well and who will have a poor outcome. Apart from a framework for the identification of ED patients with NSC in a procedural way, the BANC study also proposes definitions for serious conditions.

Several studies previously reported on patients with NSCs in the ED, using different terms or definitions. Safwenberg et al.27 prospectively screened almost 13,000 ED patients regarding their presenting complaints. In this study, “general disability” was among the five most prevalent complaints (frequency 5.5%). The patients in this particular group had the highest mortality, reaching 27%. The lower prevalence of general disability compared to 13.5% NSCs found in our study may be explained by the fact that patients with the less serious ESI triage scores of 4 and 5 were not considered during BANC study enrollment. The ESI triage algorithm has been validated to accurately predict hospitalization, ED length of stay, and resource utilization. Patients who are triaged as ESI 4 and 5 usually need one or no resource, and their mortality is very low.28

However, the high mortality of patients with general disability in the Safwenberg study27 underscores the fact that patients with NSCs are at high risk for serious outcomes. Vanpee et al.4 reported that up to 20% of the older individuals (75 years and older) presenting to the ED had no specific complaints but a “general condition impairment.” Although we did not exclude patients younger than 75 years, the populations are comparable, because the majority of the BANC population was 75 years old or older. We have chosen “non-specific complaints” rather than “general condition impairment” as generic to describe the BANC study population. We felt that “general condition impairment” refers to a patient’s health status rather than to a symptom or complaint. However, “general condition impairment” may also be an appropriate term for the majority of the BANC population, similar to generalized weakness.29 Similarly, in a recent study on patients admitted to the ED because of difficulties noticed by caregivers (“home care impossible”), an acute medical problem was identified in more than half of all patients.5

In our study, NSCs such as generalized weakness or feeling exhausted were the most common leading complaints in patients triaged as needing more than one resource (ESI < 4). It is therefore of particular concern that, in this population at risk of being undertriaged or underserved, 59% turned out to have a serious condition. Moreover, the 30-day mortality rate of 6% shows that the mortality in this population is comparable to the mortality of patients admitted, for example, with community-acquired pneumonia.30

Emergency departments are strongly affected by the demographic age change. Older individuals admitted to the ED have a high risk for adverse health outcomes.31 The BANC study represents an older urban population, with 75% of the patients aged 72 and older, with many patients suffering from multiple comorbidities. Most patients expressed some form of weakness or recent falls, and it is obvious to compare the BANC study population with a “frailty population.” Fried et al.32 proposed a definition of frailty that is based on three to five measures: recent weight loss, self-reported exhaustion, poor grip strength, slow walking speed, and low physical activity. In the Cardiovascular Health Study, this definition was validated to be predictive of subsequent disability, hospitalization, and mortality.32,33 In our opinion, the term “frailty” should be limited to patients in stable condition. ED patients should not be described as frail unless a serious condition has been excluded during a full work-up. Only a minority of the patients in our population with NSCs and a nonserious condition could finally be classified as frail.

Because we could show that several predictors were significantly associated with serious conditions, we hypothesize that a serious condition can be predicted in multivariable clinical prediction models. With this work, however, it was our primary aim to delineate the process to generate and describe the particularities of the NSC population. In future work we aim to develop risk stratification models to identify subjects at high risk of serious conditions with the hope to facilitate the management of patients with NSC. Future work will have to answer how diagnosis and early treatment will affect the management of this vulnerable group of patients.


This study was conducted at a single urban tertiary care center in Switzerland. We are aware that the lack of an external validation sample limits the generalizability of the results to EDs in other areas or countries.

The BANC study population showed considerable variation in age, pointing to heterogeneity of the NSC population. It is therefore a possible concern that younger and older subjects might behave differently regarding their presentation with NSCs or their underlying serious conditions. Moreover, age and sex could not be concealed from the outcome assessors, eventually leading to some degree of incorporation bias.34 However, the direction of such bias is not obvious; it is not clear whether serious conditions would preferentially be allocated to younger or older individuals. Moreover, by virtue of a standardized approach to the NSC patient in the BANC study, patient selection has been deliberately kept to a minimum, and therefore selection bias is thought to be of lesser relevance. Similarly, several methodologic attempts were made to prevent information bias. Two independent outcome assessors categorized each patient regarding the presence of a serious condition, and all patients were followed until Day 30 post-ED presentation, to determine the outcome and therefore obtain an accurate diagnosis in all patients.34

It appears possible that the association between the ED visit and serious condition may be spurious in some instances. However, the overall admission rate of 82% greatly reduces the possibility that the association between the ED visit and serious condition is completely unrelated, although this cannot be completely excluded for the 18% of patients lacking daily observation. Finally, the size of the current sample is small and not yet intended for multivariate prediction models for serious condition.


Patients with non-specific complaints are at high risk of an unfavorable outcome. Risk stratification tools are urgently needed to efficiently manage patients with nonspecific complaints in the ED. We provide a framework of definitions acceptable for clinical and scientific purposes and propose our definition of non-specific complaints and serious condition for future use in ED research and clinical practice.


The authors thank Karen Delport and Heiner C. Bucher for helpful discussion. They also thank the outcome assessors Michael Bodmer, Sonja Nisslé, Min-Jeong Kim, and Luzia Meier as well as the members of the expert panel Lukas Hunziker and Dagmar Keller.