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Keywords:

  • public awareness;
  • response to symptoms;
  • stroke recognition;
  • stroke symptoms

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

Background

No commonly agreed definition exists for ‘stroke symptom knowledge’ among members of the general public. Recalling at least one correct stroke symptom has been used in the past. However, this criterion was not associated with rapid presentation to hospital. Rapid presentation is vital in order to provide effective acute stroke treatment.

Aims and/or hypothesis

We sought to identify a base level of community stroke symptom knowledge associated with stroke recognition when symptoms occur, an immediate ambulance call, and ‘stroke recognition and immediately calling an ambulance’ as a single sequence of events.

Methods

For six-months in 2004–2005, we identified all patients with stroke living in a defined region of Melbourne and who were transported by ambulance to one of the three hospitals. The person who called the ambulance (caller) was interviewed.

Results

One hundred ninety-eight patients were identified and 150 callers interviewed. Symptoms reported most frequently were limb weakness (67%), speech problems (57%), and facial weakness (24%). Reporting at least two of the symptoms – facial weakness, limb weakness, or speech problems (62% of callers) – was associated with stroke recognition (P = 0·004), immediately calling an ambulance (P = 0·065), and both ‘stroke recognition and immediately calling an ambulance’ (P = 0·053).

Conclusions

Knowing at least two of the symptoms – facial weakness, limb weakness, and speech problems – appears to be an appropriate indicator of stroke symptom knowledge as it is associated with stroke recognition and appropriate action. Recognizing stroke symptoms and immediately calling an ambulance increase the potential to reduce prehospital time delays and improve eligibility of acute stroke patients for rapid treatment.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

Stroke is the third most common cause of death in the Australian community and the single greatest cause of disability [1, 2]. However, the general public appears to know little about the signs and symptoms of stroke and what to do when symptoms occur [3, 4]. Furthermore, there is limited knowledge about the relationship between stroke symptom knowledge and time to hospital presentation [5, 6].

Time is the most critical factor impacting on the appropriate performance of acute stroke interventions [7], with many patients excluded from treatment with alteplase because the delay to presentation exceeds the time when treatment is efficacious [8, 9].

Public awareness messages, such as ‘Stroke Chain of Survival’ (United States) and ‘Face, Arms, Speech, Time’ (FAST) (Australia and United Kingdom) [10, 11], have been developed to reduce presentation delays. These programs are based on the premise that better knowledge of stroke symptoms will lead to improved recognition of stroke and an immediate call for an ambulance.

No commonly agreed standard exists to define an appropriate level of ‘stroke symptom knowledge’ among the general public. Some authors have used recall of at least one stroke symptom as a measure of ‘stroke symptom knowledge’ following stroke education [12-15]. However, recalling at least one symptom has not been associated with shorter times to hospital presentation [16].

Developing community stroke symptom knowledge is vital, but it is unclear what minimum level of stroke symptom knowledge is required to reduce delays to treatment and improve outcomes for acute stroke patients. The impact of community awareness campaigns on the level of community stroke symptom knowledge is only truly applicable to the clinical environment if it is associated with recognition of stroke when it occurs and a rapid call for ambulance assistance [17].

In this current study, we aimed to quantify ‘stroke symptom knowledge’ in an applied way that may be used to evaluate community awareness interventions aimed at reducing time to hospital presentation. Specifically, we aimed to identify a base level of stroke symptom knowledge associated with both recognition of stroke and an immediate call for ambulance assistance.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

This was a prospective observational study of patients from a geographically defined region (population of 383 000) in metropolitan Melbourne who presented by ambulance to one of the three public hospital emergency departments with a final emergency department diagnosis of ‘stroke’ or ‘transient ischemic attack’ (TIA).

The study region was selected for several reasons. First, Melbourne Metropolitan Ambulance Service (now Ambulance Victoria) records for the previous 12 months indicated that approximately 90% of all ambulance-transported patients (n = 762) from this geographic region were transported to one of the three hospitals, namely, Austin Hospital (60%), Northern Hospital (30%), and Royal Melbourne Hospital (RMH) (10%). Second, surveillance of this region was expected to yield a sample of approximately 250 patients over a six-month period, a reasonable snap shot of current practice. Third, the included hospitals provided different stroke services. Austin Hospital and RMH both have large comprehensive stroke services offering intravenous thrombolysis to eligible patients. Northern Hospital offered stroke unit care with a multidisciplinary team but, at the time of the study, did not provide thrombolysis and there was no on-site access to neurological specialist or neurosurgical expertise.

Emergency department (ED) computer records were used to identify potential patients for inclusion in the study. Patients were eligible for inclusion in the study if they were ≥18 years, resident within the study region, transported to hospital by ambulance, and diagnosed by ED staff as having had a stroke or TIA. The person who called for ambulance assistance (‘the caller’) was identified for each case. ‘Caller’ participants were excluded from the study if they were unable to be identified, aged <18 years, or were medical practitioners or members of the police or other emergency services. All callers identified were followed up immediately, often in the emergency department, to minimize any loss of knowledge over time. ‘Callers’ were interviewed using a structured face-to-face questionnaire to obtain demographic data and their description of the stroke event. Participants were asked questions regarding stroke symptoms, their assessment of the patient's problem, and action taken prior to the ambulance call.

Definitions

‘Stroke recognition’ was defined as callers who stated at interview ‘I thought the problem was stroke’ (or similar response).

‘An immediate call for ambulance assistance’ was defined when the caller reported that their first response to symptom onset was to call an ambulance.

Ethical approval for the study was obtained from each participating hospital. Informed consent was obtained from the patient and caller before any interview was conducted.

Data analysis

Univariable logistic regression was undertaken to explore the associations between different levels of stroke symptom knowledge and (a) stroke recognition and (b) immediate ambulance call. A multivariable model was adjusted for confounding factors (age and sex of the caller) and all other variables with a two-sided P value ≤0·1. Backward stepwise elimination was used to remove all variables with a P value >0·1. Each eliminated variable was reentered into the final model to confirm its exclusion or inclusion.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

One hundred ninety-eight patients were recruited into the study (n = 198). One hundred fifty callers (n = 150) were interviewed, seven callers refused to participate, four could not be located, and 27 were excluded under the study exclusion criteria.

In total, 43% of callers were male and the mean age was 63 years (Table 1). Stroke recognition was reported in 93 cases (62%), while 85 callers (56%) reported immediately calling an ambulance. In 80 cases (53%), stroke was recognized and an immediate ambulance call was made.

Table 1. Univariable and multivariable associations between specific stroke symptoms recalled by callers and (1) recognizing the problem as stroke and (2) an immediate call for ambulance assistance (n = 150)
Variablesn (%)Recognizing the problem as strokeImmediate call for ambulance assistance
UnivariableMultivariableUnivariableMultivariable
OR (95% CI)P valueOR (95% CI)P valueOR (95% CI)P valueOR (95% CI)P value
  1. *Insufficient sample size to calculate an odds ratio. Multivariable analyses are adjusted for all the variables listed in this column. CI, confidence interval; NSF,National Stroke Foundation; OR, odds ratio.

Symptoms recalled         
Vision problems11 (7)1·07 (0·30–3·86)0·91  0·91 (0·26–3·13)0·88  
Dizziness, loss of balance, fall25 (17)0·74 (0·31–1·77)0·50  0·66 (0·28–1·56)0·34  
Numbness14 (9)1·60 (0·47–5·35)0·45  2·03 (0·61–6·80)0·25  
Weakness, paralysis of limbs101 (67)1·98 (0·98–3·97)0·0551·73 (0·84–3·54)0·1351·24 (0·63–4·47)0·54  
Weakness, paralysis of the face36 (24)2·63 (1·11–6·29)0·0292·62 (1·08–6·31)0·0321·74 (0·79–3·08)0·17  
Loss of consciousness26 (17)0·66 (0·28–1·56)0·35  0·41 (0·17–0·97)0·0430·41 (0·17–0·98)0·045
Difficulty speaking or understanding86 (57)1·52 (0·78–2·97)0·21  1·43 (0·75–2·76)0·27  
Headache16 (11)0·76 (0·26–2·18)0·62  0·74 (0·26–2·10)0·57  
Difficulty swallowing2 (1)*   *   
Demographics         
Male sex65 (43)0·68 (0·35–1·33)0·260·72 (0·35–1·46)0·360·91 (0·48–1·75)0·780·98 (0·49–1·98)0·96
Caller age <45 years34 (23)0·66 (0·38–1·83)0·190·66 (0·28–1·52)0·330·60 (0·28–1·31)0·210·57 (0·26–1·27)0·17
Family stroke history58 (39)1·27 (0·65–2·53)0·701·08 (0·52–2·26)0·831·28 (0·66–2·49)0·721·13 (0·56–2·29)0·73
Aware of stroke in the media55 (37)1·85 (0·91–3·76)0·0891·49 (0·98–5·82)0·291·77 (0·89–3·53)0·101·78 (0·89–3·58)0·10
Aware of the NSF41 (27)2·35 (1·05–5·27)0·0382·33 (1·03–5·29)0·0431·46 (0·70–3·07)0·311·53 (0·69–3·42)0·29

The only demographic factor associated with stroke recognition was awareness of the National Stroke Foundation (NSF) (P = 0·043). No demographic variable was associated with an immediate call for ambulance assistance (Table 1).

Stroke symptoms recalled

Callers most frequently recalled symptoms of facial weakness (droop) (24%), arm weakness (67%), and speech problems (57%) (Table 1). Facial weakness (P = 0·029) was the only single symptom associated with stroke recognition (Table 1). No individual symptom was positively associated with an immediate call for ambulance assistance (Table 1).

Knowledge of more than one stroke symptom

When clustering was used to assess factors associated with stroke recognition, we found that recalling ‘limb weakness and face weakness’ (P = 0·007), ‘limb weakness and speech problems’ (P = 0·022), and ‘facial weakness and speech problems’ (P = 0·063) was associated with stroke recognition (Table 2). Recalling at least two of the three symptoms was independently associated with stroke recognition (P = 0·004).

Table 2. Univariable and multivariablea associations between clusters of stroke symptoms recalled by callers and (1) recognizing the problem as stroke and (2) seeking ambulance assistance (n = 150)
Symptoms recalledn (%)Recognizing the problem as strokeImmediate call for ambulance assistance
UnivariableMultivariableaUnivariableMultivariablea
OR (95% CI)P valueOR (95% CI)P valueOR (95% CI)P valueOR (95% CI)P value
  1. a

    Multivariable logistic ORs are adjusted for demographic variables for each symptom cluster. Demographic variables included were male sex, age <45, family history of stroke, aware of stroke in the media, and aware of the NSF. None of these demographic variables was associated with stroke recognition in any of the multivariable models. CI, confidence interval; NSF, National Stroke Foundation; OR, odds ratio.

Limb weakness and speech problems68 (45)2·23 (1·22–4·42)0·0222·0 (1·03–4·23)0·0421·83 (0·95–3·54)0·0721·82 (0·92–3·600·084
Limb weakness and facial weakness28 (19)4·61 (1·51–14·09)0·0074·82 (1·53–15·19)0·0072·19 (0·90–5·35)0·0852·38 (0·94–6·00)0·067
Facial weakness and speech problems21 (14)2·96 (0·94–9·30)0·0633·08 (0·95–10·01)0·0612·78 (0·96–8·05)0·0593·04 (1·01–9·14)0·047
Recall of two or more of the following: limb weakness, facial weakness, and speech problems93 (62)2·96 (1·49–5·58)0·0022·86 (1·41–5·81)0·0041·91 (0·99–3·67)0·051·89 (0·96–3·73)0·065

Each pair of the three frequently reported symptoms exhibited a strong but borderline association with an immediate ambulance call [‘limb weakness and face weakness’ (P = 0·067), ‘limb weakness and speech problems’ (P = 0·084), and ‘facial weakness and speech problems’ (P = 0·047)] (Table 2). When adjustment was made for demographic variables, the ability to recall at least two symptoms was associated with seeking immediate ambulance assistance (P = 0·065) (Table 2).

Each pair of the three frequently reported symptoms exhibited a borderline association with ‘stroke recognition and an immediate ambulance call’ (Table 3). Furthermore, the ability to recall at least two symptoms was associated with ‘stroke recognition and an immediate ambulance call’ (P = 0·029) (Table 3). After adjustment for demographic variables, the ability to recall at least two symptoms (P = 0·053) and awareness of stroke in the media (P = 0·045) were associated with ‘stroke recognition and an immediate ambulance call’ (Table 3). More than one-third of callers (37%, n = 55) reported stroke being mentioned in the media with 32 callers (21%), stating that they had gained knowledge of stroke from television programs, including news and advertisements.

Table 3. Univariable and multivariablea associations between clusters of stroke symptoms recalled by callers and ‘recognizing the problem as stroke and immediately seeking ambulance assistance’ (n = 150)
Variablesn (%)UnivariableMultivariablea
OR (95% CI)P valueOR (95% CI)P value
  1. a

    Multivariable analyses were adjusted for demographic variables for the symptom cluster: ‘recall of two or more of limb weakness, facial weakness, and speech problems’. Demographic variables included were male sex, age <45, family history of stroke, aware of stroke in the media, and aware of the NSF. Only one of these variables (‘Aware of stroke in the media’) was associated with ‘stroke recognition and an immediate ambulance call’ in the multivariable model. CI, confidence interval; NSF, National Stroke Foundation; OR, odds ratio.

Symptoms recalled     
Limb weakness and speech problems68 (45)1·87 (0·97–3·59)0·061  
Limb weakness and facial weakness28 (19)2·11 (0·89–5·03)0·092  
Facial weakness and speech problems21 (14)2·46 (0·89–6·74)0·08  
Recall of two or more of the following: limb weakness, facial weakness, and speech problems93 (62)2·08 (1·08–4·02)0·0291·93 (0·99–3·77)0·053
Aware of stroke in the media55 (37)2·20 (1·11−4·36)0·0252·04 (1·01–4·01)0·045

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

We found that people recalling at least two of the three most commonly recognized symptoms of stroke, i.e., facial weakness, limb weakness, and speech difficulties, was associated with a much greater likelihood of recognizing the problem as stroke than any one of these symptoms. These symptoms are those specified in the FAST stroke assessment tool because of their positive predictive values for stroke [18, 19].

Stroke symptom knowledge has been described in previous studies as the ability to recall one or more stroke symptoms [13, 15]. This categorization separates those with some stroke symptom knowledge from those with no knowledge. However, this cutoff may not be meaningful in reducing delay times for stroke. An appropriate level of stroke symptom knowledge should be associated with not only the ability to recognize stroke when it occurs but also the capacity to know to call an ambulance [17].

The observation that an ability to recall at least two of the FAST symptoms was significantly associated with stroke recognition and the action of immediately calling an ambulance demonstrates that knowledge can lead to action. The ability to develop and transfer prior stroke symptom knowledge into recognition and action remains the foundation element of stroke community awareness campaigns [10, 11].

We specifically aimed to determine a definition of stroke that was associated with both recognition and action during a real stroke event. Recalling at least two of the FAST symptoms (62% of all callers) met these criteria. This level of recognition is approximately double that reported by Hickey et al. in their study of the general public [20]. Others have reported that between 37% and 47% would call an ambulance for stroke [3, 15, 21]. Using simulated research recall tasks, as used by Billings-Gagliardi and Mazor [3], may only go part of the way to replicating real world emergency events. To address this issue, we sought out the person who made the ambulance call during a real stroke event. No previous study has uniformly included interviews with callers. Callers provided an in-depth account of the events as they were active participants in the process of recognizing symptoms, the decision to seek care, and calling an ambulance [6]. While every effort was undertaken by the investigators to reduce any recall bias, some discrepancies may exist in the recall of information emanating from such a stressful event.

A limitation of this study is that we only included patients with stroke who arrived by ambulance. No information was available on those who presented by private transport or did not present to hospital. This study does, however, provide robust data that reflect community awareness and response to stroke symptom onset over a six-month period in a large metropolitan city. The analysis undertaken in this study directly mirrors the symptoms currently in use by NSF in their FAST community awareness campaign [11]. The additional finding that awareness of stroke in the media was associated with both stroke recognition and an immediate ambulance call supports the assertion that mass media advertising can change both knowledge and behavior following the onset of stroke symptoms [5].

In conclusion, there is no right approach to defining an intangible such as community stroke symptom knowledge. However, setting a clear benchmark for stroke symptom knowledge that is easily applied in a clinical environment is important if we wish to understand the impact of interventions on the knowledge, behavior, and actions of the public following the onset of stroke symptoms. Furthermore, having uniformly agreed definitions may assist comparing the results of different community awareness interventions around the world.

Our findings provide evidence that knowing at least two of the FAST symptoms is associated with both understanding what is wrong (stroke recognition) when stroke symptoms occur and knowing what to do (immediately call an ambulance). Further research is required to better understand care-seeking decisions following symptom onset and the causes of delay to hospital presentation for patients with acute stroke.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References
  • 1
    Hankey GJ. Transient ischaemic attacks and stroke. Med J Aust 2000; 172:394400.
  • 2
    Mathers CD, Vos ET, Stevenson CE, Begg SJ. The burden of disease and injury in Australia. Bull World Health Organ 2001; 79:10761084.
  • 3
    Billings-Gagliardi S, Mazor KM. Development and validation of the stroke action test. Stroke 2005; 36:10351039.
  • 4
    Nicol MB, Thrift AG. Knowledge of risk factors and warning signs of stroke [Review]. Vasc Health Risk Manag 2005; 1:137147.
  • 5
    Hodgson CS, Lindsay P, Rubini F. Can mass media influence emergency department visits for stroke? Stroke 2007; 38:21152122.
  • 6
    Mosley I, Nicol M, Donnan G, Patrick I, Dewey H. Stroke symptoms and the decision to call for an ambulance. Stroke 2007; 38:361366.
  • 7
    Evenson KR, Rosamond WD, Morris DL. Prehospital and in-hospital delays in acute stroke care. Neuroepidemiology 2001; 20:6576.
  • 8
    Donnan GA, Davis SM, Parsons MW, Ma H, Dewey HM, Howells DW. How to make better use of thrombolytic therapy in acute ischemic stroke. Nat Rev Neurol 2011; 7:400409.
  • 9
    Hacke W, Caplan L. Challenges for cerebrovascular disease. Front Neurol 2010; 1:3. Epub 2010/12/29.
  • 10
    American Stroke Association. Operation stroke. 2007. Available at http://www.strokeassociation.org (accessed May 23 2007); http://www.strokeassociation.org
  • 11
    National Stroke Foundation. F.A.S.T. interactive website. 2010. Available at http://www.strokefoundation.com.au (accessed September 28 2010); http://www.signsofstroke.com.au/
  • 12
    Gutierrez-Jimenez E, Gongora-Rivera F, Martinez HR, Escamilla-Garza JM, Villarreal HJ, GECEN Investigators. Knowledge of ischemic stroke risk factors and warning signs after a health education program by medical students. Stroke 2011; 42:897901.
  • 13
    Kothari R, Hall K, Brott T, Broderick J. Early stroke recognition: developing an out-of-hospital NIH Stroke Scale. Acad Emerg Med 1997; 4:986990.
  • 14
    Schneider AT, Pancioli AM, Khoury JCet al. Trends in community knowledge of the warning signs and risk factors for stroke. JAMA 2003; 289:343346.
  • 15
    Yoon SS, Heller RF, Levi C, Wiggers J, Fitzgerald PE. Knowledge of stroke risk factors, warning symptoms, and treatment among an Australian urban population. Stroke 2001; 32:19261930.
  • 16
    Schroeder EB, Rosamond WD, Morris DL, Evenson KR, Hinn AR. Determinants of use of emergency medical services in a population with stroke symptoms: the Second Delay in Accessing Stroke Healthcare (DASH II) Study. Stroke 2000; 31:25912596.
  • 17
    Mikulik R, Bunt L, Hrdlicka D, Dusek L, Vaclavik D, Kryza J. Calling 911 in response to stroke: a nationwide study assessing definitive individual behavior. Stroke 2008; 39:18441849.
  • 18
    Harbison J, Hossain O, Jenkinson D, Davis J, Louw SJ, Ford GA. Diagnostic accuracy of stroke referrals from primary care, emergency room physicians, and ambulance staff using the face arm speech test. Stroke 2003; 34:7176.
  • 19
    Harbison J, Hossain O, Jenkinson D, Davis J, Louw SJ, Ford GA. Diagnostic accuracy of stroke referrals from primary care, emergency room physicians, and ambulance staff using the face arm speech test. Stroke 2003; 34(1):7176. Epub 2003/01/04.
  • 20
    Hickey A, Holly D, McGee H, Conroy R, Shelley E. Knowledge of stroke risk factors and warning signs in Ireland: development and application of the Stroke Awareness Questionnaire (SAQ). Int J Stroke 2012; 7:298306.
  • 21
    Fussman C, Rafferty AP, Lyon-Callo S, Morgenstern LB, Reeves MJ. Lack of association between stroke symptom knowledge and intent to call 911. A population-based survey. Stroke 2010; 41(7):15011507.