Stroke Symptoms and the Decision to Call for an Ambulance
Background and Purpose— Few acute stroke patients are treated with alteplase, partly because of significant prehospital delays after symptom onset. The aim of this study was to determine among ambulance-transported stroke patients factors associated with stroke recognition and factors associated with a call for ambulance assistance within 1 hour from symptom onset.
Methods— For 6 months in 2004, all ambulance-transported stroke or transient ischemic attack patients arriving from a geographically defined region in Melbourne (Australia) to 1 of 3 hospital emergency departments were assessed. Tapes of the call for ambulance assistance were analyzed and the patient and the caller were interviewed.
Results— One hundred ninety-eight patients were included in the study. Stroke was reported as the problem in 44% of ambulance calls. Unprompted stroke recognition was independently associated with facial droop (P=0.015) and a history of stroke or transient ischemic attack (P<0.001). More than half of the calls for ambulance assistance were made within 1 hour from symptom onset and only 43% of these callers spontaneously identified the problem as “stroke.” Factors independently associated with a call within 1 hour were: speech problems (P=0.009), caller family history of stroke (P=0.017), and the patient was not alone at symptom onset (P=0.018).
Conclusions— Stroke was reported as the problem (unprompted) by <50% of callers. Fewer than half the calls were made within 1 hour from symptom onset. Interventions are needed to more strongly link stroke recognition to immediate action and increase the number of stroke patients eligible for acute treatment.
Stroke remains the third leading cause of death and the largest cause of disability in Australia.1 Despite these realities, there is poor knowledge among both the general community and stroke survivors about the nature of stroke, risk factors, symptoms, and signs of stroke and what to do if a stroke occurs.2
Intravenous thrombolysis with alteplase is highly effective treatment when administered within 3 hours of the onset of ischemic stroke.3 However, in Australia, only ≈3% of stroke patients currently receive this treatment, mainly as a consequence of delayed presentation to hospital.4 Researchers have previously identified that rapid identification of stroke in the community and transport by ambulance has a direct relationship with reduced delay and increased eligibility for intravenous alteplase.5,6
Comparisons have been made between the treatment protocols for acute myocardial infarction and stroke. In a major Australian study published in 2003, only 60% of acute myocardial infarction patients received thrombolysis within the British Heart Foundation care time guidelines, partly because of significant delays in calling for ambulance assistance after the onset of symptoms.7
Previous stroke studies have examined factors that may influence the timing of a call for ambulance assistance.8–11 These factors include patient socio-demographics, clinical factors, stroke recognition, and the identity of the caller. Although much valuable information has been identified, prehospital delays remain.
With the ultimate goal of reducing prehospital delays and improving therapeutic efficacy, we focused on the time period from symptom onset to seeking care (longest delay period)12 and on patients who do seek ambulance assistance (shortest delay group).12 We sought to identify factors that could be used to develop more effective strategies to reduce delays and increase eligibility of patients for acute stroke therapies.
Our aim was to determine what factors influence the decision to call for ambulance assistance after symptom onset among a prospective cohort of ambulance-transported acute stroke patients, ie, specifically, to identify factors associated with unprompted stroke recognition and to identify factors associated with a call for ambulance assistance within one hour from symptom onset.
This was a prospective observational study of patients from a geographically defined region (population 383 000) in metropolitan Melbourne who presented by ambulance to 1 of 3 public hospital emergency departments and were given a final emergency department diagnosis of stroke or transient ischemic attack. This study region was selected for several reasons. First, Melbourne Metropolitan Ambulance Service records for the previous 12 months indicated that ≈90% of all ambulance-transported stroke patients (n=762) from this geographic region were transported to 1 of 3 hospitals, namely Austin Hospital (60%), Northern Hospital (30%), and Royal Melbourne Hospital (RMH) (10%). Second, recruitment of patients from this area via surveillance of these 3 hospitals was expected to yield a sample of ≈250 patients over a 6-month period, a reasonable snapshot of current practice. Third, the included hospitals provided different stroke services. Austin Hospital and the RMH both have large comprehensive stroke services offering intravenous thrombolysis to eligible patients. Northern Hospital offers stroke unit care with a multi-disciplinary team but, at the time of the study, did not provide thrombolysis, and there was no onsite access to specialist neurological or neurosurgical expertise.
In Melbourne, Australia the Melbourne Metropolitan Ambulance Service provides the sole emergency ambulance service in the city. Emergency contact with the service is through a single “000” phone number. Ambulance call takers use a uniform question sequence and protocol, and all calls are recorded.
Emergency department computer records at the 3 participating hospitals were used to identify potential patients for inclusion in the study. Patients were eligible for inclusion in the study if they were 18 years of age or older, were residents within the study region, were transported to hospital by ambulance, and were diagnosed by emergency department staff as having had a stroke or transient ischemic attack. Patients with subarachnoid hemorrhage were excluded. The person who called for ambulance assistance (“the caller”) was identified for each case. Patients were excluded if they had been transferred from another hospital by ambulance or were younger than 18 years of age. “Caller” participants were excluded from the study if they were unable to be identified (bystander), younger than 18 years of age, were medical practitioners, members of the police or other emergency services, or if they had an illness (physical or mental) that may be affected by involvement in the study.
Tapes of all calls for ambulance assistance were reviewed using a uniform screening tool to evaluate the reported symptoms, any diagnosis offered by the caller (stroke or other), medical history reported, and symptom onset time provided without prompting by the call taker. The symptoms were transcribed and then coded. “Stroke recognition” was defined as callers who mentioned “stroke” (unprompted) during the call. The reaction and decisions of the call taker (dispatcher) were recorded. Each patient’s clinical details, history, and event description were obtained from hospital medical records and the ambulance patient care record.
The patient and “the caller” were interviewed using a structured face-to-face questionnaire to obtain demographic data and their description of the stroke event. Involvement of any third party was documented. Patients and callers were asked about their responses to the onset of stroke symptoms and about factors that influenced their decision to seek ambulance assistance. If the patient was unable to answer for themselves because of dysphasia, altered consciousness or cognitive impairment, the next of kin was interviewed as a proxy.
Research Ethics Committee approval for the study was obtained from the Austin Hospital, RMH, and the Northern Hospital. The study was also approved by Management of the Metropolitan Ambulance Service. Informed consent was sought from the patient or next of kin (as appropriate) and from the caller before any data were collected and interviews conducted.
Univariate logistic regression was undertaken to explore the associations between a range of demographic, clinical, and other factors and the outcomes of unprompted stroke recognition and calls for ambulance assistance within 1 hour from symptom onset.
Variables with a univariate P<0.10 were then entered into a multivariate backward stepwise linear regression model for each outcome of interest. The least significant variable was removed and the model re-run. This process was repeated until all variables had P<0.05. P<0.05 was considered significant.
Two hundred seven patients were identified as eligible for inclusion in the study. Eight patients refused to participate and one patient could not be located. One hundred ninety-eight ambulance-transported patients were recruited into the study over a 6-month period. This represented ≈56% of all stroke presentations from the region. Demographic information for included patients is shown in Table 1. No eligible patients were recruited at RMH. Ten potential patients presented at RMH but were excluded as they were transferred by ambulance from the Northern Hospital. Caller participation rates are shown in Figure 1.
We found that the symptoms spontaneously reported by callers were: speech problems (41%), limb weakness (38%), altered consciousness (28%), fall (17%), facial droop (11%), and numbness (9%). Other symptoms reported were headache, dizziness, and unsteadiness.
Stroke was spontaneously reported as the problem in 64 (44%) calls. This increased to 67 (47%) after prompting by the call taker. Factors found to be associated with unprompted stroke recognition using univariate analysis are shown in Table 2. Using multivariate analysis, the only factors independently associated with unprompted stroke recognition were: facial droop (P=0.015) and patient history of stroke or transient ischemic attack reported in the call (P=0.001). Negative colinearity was identified between change in consciousness and both facial droop and limb weakness.
Seventy-four calls for ambulance assistance (52%) were made within 1 hour from the onset of symptoms. In the majority of these rapid calls for ambulance assistance (57%) the caller did not specifically “recognize” that the problem was stroke. Factors found to be associated with a call for ambulance assistance within 1 hour of symptom onset on univariate analysis are shown in Table 3. In the multivariate analysis, the factors independently associated with the call for an ambulance being made within 1 hour of symptom onset were: speech problems reported in the call (P=0.009), the caller had a family history of stroke (P=0.017), and the patient was not alone at the onset of symptoms (P=0.018).
The person who made the call for ambulance assistance was identified from the Melbourne Metropolitan Ambulance Service tape (Figure 2). The most frequent caller was the patient’s daughter (29%). Importantly, the patient was the caller in only 3% of cases. At the time of the stroke, the patient was at home in 80% of cases and in residential care in 9% of cases. In 20% of cases, the patient was alone at the onset of symptoms. If other people were present with the patient this was most commonly the patient’s partner (Figure 2).
As shown in Figure 2, there is a mismatch between the person with the patient at symptom onset and the person who made the call for ambulance assistance. In half of all cases (51%), the immediate response of the patient or the person with them at the onset of symptoms was to consult another person (most commonly a relative). The majority of those contacted (56%) traveled to the patient’s home before calling the ambulance. Factors associated with consulting an external party before calling an ambulance were assessed. In the multivariate analysis, the only factors independently associated with external consultation were facial droop (P=0.04), patient alone at onset (P=0.046), and limb weakness (P=0.052.)
In one-third of cases, the caller discovered the patient in a state such that the patient was unable to respond or seek assistance. In a further 46% of cases the patient denied or was unaware of the symptoms (17%) or did not recognize the severity of the problem and was “waiting for the symptoms to go away” (29%).
Based on information reported by the callers, ambulance call takers identified the key problem as stroke in 53% of cases. An ambulance was dispatched with the highest priority code (level 1, lights and sirens) in 84% of cases.
This real-world study was designed to investigate the processes involved in seeking ambulance care after the onset of stroke symptoms. We found that in less than half of all calls stroke was recognized as the specific problem, whereas more than half the time the problem was assessed as serious enough to call an ambulance within 1 hour of symptom onset. Recognition of a facial droop and reporting a patient’s history of stroke were the only factors independently associated with stroke recognition in this study. The negative colinearity identified between change in consciousness and both facial droop and limb weakness was an interesting finding. We suspect that callers readily recognized an altered conscious level as a serious emergency situation and appropriately reported this without regard for more specific stroke symptoms. Although stroke was not specifically “recognized,” the caller responded appropriately by seeking immediate ambulance assistance.
The symptoms reported by callers in this study were similar to those reported in a previous German study.9 However, in our current study stroke was mentioned (unprompted) during the call twice as frequently as in the German study. This difference might be explained by the younger age of callers in the current study.
Recognition of specific stroke symptoms may not directly lead to a rapid call for ambulance assistance. There was no direct relationship between reporting stroke as the problem and a rapid call for ambulance assistance. Only 22% of all callers recognized the problem as stroke and called within 1 hour from the onset of symptoms. Factors independently associated with a rapid call for an ambulance were recognition of a speech problem, patient not alone at the onset of symptoms and the caller had a family history of stroke. More severe symptoms of limb weakness and altered consciousness were not associated with a rapid call. We speculate that this may be caused by patients who were found, alone, long after onset, unable to move or unconscious.
Important findings to emerge from this study were the reliance of stroke patients on others to provide advice and assistance even when they were not present with the patient. One-third of patients were found unable to think, act, or communicate. Patients only called an ambulance for themselves 3% of the time and frequently relied on external consultation (with family members). Previous studies have identified similar low patient call rates, reported who was contacted when an ambulance was not called and reported categories of ambulance callers.9–12 However, the way patients interpret symptoms, develop their own coping mechanisms, and engage others in the decision to call an ambulance was less clear. This study identifies the callers and how they became involved in seeking ambulance assistance. Previous studies have reported increased delays when third parties including a local doctor are involved.12 The process of seeking “lay referral” in deciding to call for an ambulance after stroke has not been previously described.
In these cases the “caller” was often not with the patient at the onset of symptoms. Delays occurred while they were contacted for advice. In turn, this third party frequently decided to assess the situation personally before calling an ambulance. These callers reported high levels of stroke recognition and rapid response once on site but delays had already occurred while waiting for them to attend. Interestingly, stroke recognition did not remove the need for consultation before action. Contrary to previous studies, age and sex was not a predictor of external consultation.13 We speculate that cultural and language factors may underlie the need for consultation as the study area contains a higher proportion of people of non-English speaking background and born overseas.14 Unfortunately, information about preferred language and country of birth was not collected in this study.
Agreement among family members to act immediately may remove the need to consult others before calling an ambulance for stroke. Family members should know that if contacted for advice in an emergency that the best response is to call an ambulance. Any program aimed at increasing stroke awareness needs to target a broad community audience, perhaps focusing on people in their middle years. In this study, more than half of ambulance calls were made by family members at least one generation younger than the patient. Quick action must be linked to stroke situation recognition. Knowledge of the benefits of immediately calling an ambulance may reduce pre-hospital delays more than symptom recognition alone.
No study in Australia has investigated the actual problems reported by ambulance callers after stroke. One of the strengths of this study is that the response to stroke is recorded in real time, and the findings do not rely on the use of artificial recall or recognition research tasks. However, no information was obtained about stroke patients who arrived at hospital by private transport, or from stroke patients that did not seek hospital-based care. Ten potential patients excluded from the study presented to RMH as inter-hospital transfers. This group of patients was unidentifiable in the preliminary data and may have led to an overestimation of expected patients at RMH. Nevertheless, this study included a large representative sample of ambulance-transported stroke patients from metropolitan Melbourne and provides robust data that will inform the development of future intervention strategies to reduce delays in stroke recognition and hospital arrival so that more people can receive effective acute stroke therapies.
If delays continue to occur from the onset of symptoms to seeking appropriate care then the benefits of quality acute treatments for stroke will be lost. Further research is needed to understand the behavior of people if they experience or observe a stroke event.
We acknowledge the work of Li Chun Quang in providing computer assistance and the Metropolitan Ambulance Service, Melbourne, Australia, for their advice and assistance in this research project.
Sources of Funding
This work was supported by a grant from the National Health and Medical Research Council, Centre for Clinical Research Excellence (Neuroscience), and administered by the National Stroke Research Institute and the University of Melbourne, Australia.
- Received August 30, 2006.
- Accepted September 20, 2006.
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