stroke - emergency medical system
accidente cerebrovascular - servicios de emergencias médico
Stroke is the second leading cause of mortality and the third cause of disability
worldwide[1 ],[2 ]. With the aging of populations, concern is growing about a potentially larger impact
of the stroke burden on public health[3 ],[4 ]. This impact can be diminished by early thrombolytic treatment as this reduces disability
and improves outcomes after ischemic stroke[5 ].
The principal reason for non-use of IV rtPA is delayed arrival time at the hospital[6 ]. Causes for this delay may be specific to particular characteristics of each population,
however lack of recognition of stroke symptoms and slow activation and response of
emergency medical services (EMS) are frequently reported reasons[7 ],[8 ],[9 ],[10 ],[11 ].
Information about the recognition of stroke symptoms, the role of EMS for stroke patients’
transportation and their impact on arrival times in Latin America is scant. Data from
Brazil show an alarming lack of knowledge of stroke symptoms and activation of EMS
in the general population[12 ],[13 ]. However, there are no studies exploring this topic in patients with prior stroke[14 ].
In Argentina, where thrombolytic therapy is not widely utilized, we hypothesize that
low stroke awareness in the general population and in non-neurologist medical providers,
as well as the lack of a rapid referral system for stroke care may negatively impact
arrival times at hospital, negatively affecting the use of thrombolytic therapy.
Our aim was to evaluate the pattern of recognition of stroke symptoms, utilization
of EMS and their impact on arrival times at the hospital in our population.
METHODS
This was a retrospective review of hospital records and prospective structured telephone
interviews of 100 consecutive patients admitted to the stroke unit of our institution
with a diagnosis of acute ischemic stroke from November 2012 to July 2013. As several
studies suggest that the population awareness and response to transient symptoms are
different[15 ], transient ischemic attacks (TIAs) were excluded from this study. Patients or caregivers
were contacted by a neurologist and questioned about their interpretation of their
symptoms, and subsequent response, using a predesigned standardized questionnaire
([Figure 1 ]). Time between admission and phone contact was from one to seven months.
Figure 1 Close ended questionnaire.
Population
Patients were selected from hospital records of tertiary neurological hospital of
the city of Buenos Aires. Its stroke unit admits approximately 180 patients with ischemic
stroke per year.
According to a 2010 national census, the city of Buenos Aires has 2.9 million habitants.
The educational level, socioeconomic status and private healthcare coverage in this
population is higher than the average in Argentina[16 ]. Besides being a regional referral center, approximately 260,000 people, mostly
those with private health insurance, are within the influence area and have access
to acute stroke care in our hospital.
Health care system
The health care system in Argentina is segmented and heterogeneous because of the
lack of integration between the public system, social security and private sector.
It is based on the public provision of health for every habitant. Additionally, people
can be covered by the social security system comprising workers’ organizations “health
care insurance” (52%), government-funded social insurance for the retired population
“PAMI” (8.3%), or by private health insurances (9%)[16 ]. The latter, in turn, subcontract to emergency medical companies.
Definitions
Stroke was defined as an acute focal neurological deficit lasting more than 24 hours.
The word used to refer to stroke in the Spanish version of the questionnaire was ACV,
the acronym of “accidente cerebrovascular” (cerebrovascular accident). A TIA was considered to be an acute neurological deficit
lasting < 24 hours with a normal physical examination beyond that time. Patients who
were referred with transient symptoms but had abnormal findings on the neurological
examination were considered stroke patients.
As IV rtPA efficacy decreases in a time-dependent fashion up to 4.5 hours after symptom
onset and endovascular treatments can be used in selected patients within six hours,
arrival time was segmented into 3, 4.5 and 6 hours between stroke onset and presentation
at the emergency room, for the purpose of data analysis. To investigate the causes
for which patients could not even be considered for IV rtPA treatment, patients who
arrived to hospital after 4.5 hours from stroke onset were considered to have pre-hospital
delay (PHD) and those who arrived to the hospital before 4.5 hours but had completed
initial work-up beyond that time, were considered to have hospital diagnosis delay
(HDD).
Arrival time was defined as the last time the patient was asymptomatic until arrival
at hospital. If the patients were transferred from another institution, arrival time
was considered to be from the onset of stroke symptoms until arrival at the first
center. The term “non-specialized hospital” was used to describe centers not meeting
criteria for a primary stroke center[17 ].
We defined “educational level” as the highest level of schooling that a person has
reached. It was stratified as completed elementary school, completed secondary school
or university education. Patients who had an incomplete level were allocated to the
immediate lower group.
Statistical analysis
Regression analysis was performed with EMS utilization and emergency consultation
as outcomes. Other variables included and/or considered potential confounders were
age, gender, educational level, neighborhood, previous knowledge about stroke, history
of neurological symptoms, family history of stroke, previous inpatient admission,
heart disease, presence of motor or sensory symptoms, facial weakness and National
Institutes of Health Stroke Scale (NIHSS) score at admission. Forward stepwise logistic
regression analysis was used to determine which factors correlated with the odds of
calling EMS or going to the emergency by their own means. Univariate analysis was
performed for each variable and tests with p values < 0.25 were ranked and kept for
the next step. Age, gender, and educational level were added regardless of their p
value. We then added, as a first variable, the one having the highest correlation
with the dependent variable and, if it was significant, we continued with the next
variable until no more were available. Partial F tests were conducted at every step,
and non-significant variables were removed. Fisher’s exact test was used to estimate
statistical significance of the categorical data. The local ethics committee approved
the study.
RESULTS
Five patients were lost to follow up and one had died. Thus, 84 patients and 10 caregivers
completed the telephone survey and were included in the final analysis.
Demographic characteristics
Mean age was 67 ± 20 years old. Sixty-four percent of patients were male. All patients
had at least completed elementary school and 55% had completed college education.
Thirty percent had had a stroke before the index event and 24% had relatives with
stroke ([Table 1 ]). Initial symptoms and NIHSS scores on admission are presented in [Table 2 ].
Table 1
Demographic characteristics and clinical history of patients.
Demographic Variables
n(%), n = 94
Average age (years SD)
66.5 (19.9)
Men
60
Educational level
Primary
15 (16)
Secondary
27 (29)
University
52 (55)
Medical History
HTA
56 (59.6)
Dyslipidemia
43 (45.7)
Prior stroke/TIA
29 (30,85)
Smoking
28 (29.7)
Atrial fibrillation
25 (26.6)
Diabetes
23 (24.5)
Familiar history of stroke
23 (24,5)
Ischemic cardiopathy
16 (17)
Oral contraceptives
6 (6,4)
Migraine with aura
4 (4.25)
Thrombophilia
1 (1.06)
Presenting symptom
Motor
48 (51)
Language
47 (50)
Other
18 (19.15)
Visual
14 (14.9)
Headache
13 (13.83)
Sensory
10 (10.6)
Coordination/balance/walk
9 (9.6)
Loss of consciousness
4 (4.25)
NIHSS score
< 10
84 (89.4)
10-20
7 (7.5)
> 20
3 (3.2)
HTA: hypertension ; TIA: transient ischemic attacks ; NIHSS: National Institutes of
Health Stroke Scale
Table 2
Causes of pre-hospital and hospital diagnostic delays.
Causes of PHD
n (%), n = 70
Unawareness
30 (49)
Mild symptoms
11 (15)
Transient symptoms
10 (15)
Wake-up stroke
8 (9)
Distance to hospital
4 (6)
Misdiagnosis
7 (2)
Causes of HDD
n (%), n=4
Misdiagnosis
3 (86)
Other
1 (14)
PHD: pre-hospital delay; HDD: hospital diagnostic delay.
For definitions, see Figure 1.
Arrival times, pre-hospital delay and hospital diagnostic delay
Seventy patients (75%) arrived at the hospital more than 4.5 hours after onset of
the stroke. Those patients were considered to have PHD. The principal causes were
lack of recognition of symptoms as indicators of acute stroke and mild or transient
symptoms ([Table 2 ]).
Twenty-four patients (25%) arrived at the emergency room within 4.5 hours from stroke
onset, half of them (n = 12) within 3 hours. Four of those patients had their initial
work-up completed more than 4.5 hours after stroke symptoms and did not receive rtPA.
They were considered to have HDD. Causes of initial HDD were misdiagnosis in three
patients and unavailability of brain imaging in one. All HDD patients were referred
to our center after their first evaluation in non-specialized hospitals. The referral
time was less than 24 hours in all cases. Nineteen patients (20%) were initially misdiagnosed.
Eighteen of them were first assessed by a non-neurologist physician (p < 0.001).
Pattern of utilization of EMS
The EMS were used by 37% of patients without a significant impact on arrival time.
Most patients who recognized their symptoms did not use EMS for transportation to
the hospital (p < 0.02) ([Figure 2 ]). Patients with motor symptoms were more likely to use EMS (p < 0.02) ([Figure 2 ]). Also stroke severity, measured by the NIHSS, was associated with the use of the
EMS. For each point of the NIHSS score, the chance of calling the EMS increased by
10%. Fifty-five percent of patients referred that they had received information about
stroke before their event; however this did not make them more prone to call the EMS.
Figure 2 Factors associated with the use of EMS for transportation.
IV rtPA treatment and transportation to the hospital
Ten patients (10.6%) received IV rtPA treatment. Most of them (n = 7) arrived within
three hours from stroke symptom onset. Seven out of ten treated subjects did not use
the EMS and came to our emergency in their own transportation or hired vehicles.
Interpretation of stroke symptoms
Only 21% of the patients interpreted their initial symptoms as consistent with stroke.
This group was more likely to arrive within six hours (adjusted OR 2.96 95%CI 1–8.7
p < 0.05). Also a trend in the odds of consultation in the first three, and four-and-a-half
hours was found among them, but this did not reach statistical significance. Motor
symptoms and speech disturbances were the most frequently-recognized symptoms. There
was no relationship between past history of stroke or higher educational level and
the correct interpretation of symptoms.
Patients with visual symptoms tended to consult at ophthalmological medical institutions
first (adjusted OR 0.11, 95%CI 0, 02–0.55, p < 0.01) and those with prior stroke came
directly to our institution (adjusted OR 5.8, 95%CI 1.81–18.6, p < 0.01)
DISCUSSION
Compared with prior studies[14 ], our population showed a higher educational level. All individuals had at least
completed elementary school and 55% had a college degree. In this population, economic
and educational levels may be higher than the average in Argentina[16 ] and in other Latin American populations. However, we did not find an association
between educational level and correct stroke symptom interpretation or proper use
of EMS.
Only 21% of patients recognized their initial symptoms as consistent with stroke.
This percentage is lower than previous reports in Spanish speakers[14 ]. Recognition of stroke symptoms tripled the chances of consultation in the first
six hours from symptom onset. A trend in the odds of consultation in first three and
4.5 hours was also found among those who recognized their symptoms as stroke, but
without reaching statistical significance. Similar findings have been previously published
in Spain[14 ]. It is remarkable that, despite most people seem not to acknowledge that they were
having a stroke, they did know something was wrong enough to go to the hospital.
About 37% of subjects used the EMS, suggesting poor knowledge of its availability,
lack of confidence in this system, and/or prior poor experience with its utilization.
The association between motor symptoms and stroke severity and use of EMS suggests
that, in this population, the reasons to call the ambulance were mainly physical difficulties
in using their own transportation.
Counterintuitively, the use of the EMS was not associated with shorter arrival times.
Moreover, most patients who acknowledged they were having a stroke and who were later
treated with IV rtPA did not use EMS for transportation. Although this finding neither
demonstrates a negative impact on EMS, nor points towards a recommendation for not
using them, it does raise several areas for future analysis.
In Argentina, possibly less than 1% of patients with acute stroke receive IV thrombolysis,
and this is mainly in private centers[18 ],[19 ]. Emergency services not being focused on diagnosis, triage and rapid transportation
of possible candidates for IV rtPA treatment can, at least in part, be responsible
for this. Buenos Aires does not have an organized system of stroke care and predefined
protocols for rapid referral of patients to stroke centers. Further studies are needed
to establish if EMS are playing a detrimental role in the rates of thrombolysis compared
to patients who did not use them.
In contrast to the average thrombolysis rate reported in Argentina, this group had
a high rate of thrombolysis (10%). This reflects the advantage of access to specialized
stroke care in this region, as well as the potential selection bias of a group of
patients from a single private hospital.
Prior stroke or TIA has been associated with recognition of stroke symptoms in several
studies[20 ],[21 ],[22 ]. Differing from them, we did not find this association. Our finding may reflect
a lack of education about stroke as part of secondary prevention programs.
Frequent misdiagnosis of stroke has been described among non-neurologist medical providers[23 ]. The presence of a neurologist in the emergency room has been proposed as a solution
to improve this situation[24 ]. Overall, 20% of patients in our study were initially misdiagnosed in non-specialized
hospitals or EMS, this being the principal cause of HDD and a cause of PHD. Additionally,
nine subjects arrived at the emergency department in under 4.5 hours from symptoms
onset despite having been initially misdiagnosed. Misdiagnosis was evident almost
exclusively among non-neurologists physicians. This point is particularly concerning
given that only 8.4% of patients with stroke are initially evaluated by a neurologist
in Argentina[18 ].
Our study has some limitations. Patients were contacted one to seven months after
the index stroke. This may have introduced a recall bias. However, the recognition
of stroke symptoms was poor even assuming that a recall bias could falsely increase
the percentage of patients claiming correct stroke awareness. Additionally, excluding
the questionnaire, data used for the analysis was taken from hospital records and
it was not affected by this bias. Also, we did not obtain firsthand information for
16 subjects, five were lost to follow up, one died and 10 subjects were unable to
answer. In the last group, caregivers were contacted to help with the responses.
In conclusion, even in subjects with high economic and educational level, these results
suggest low stroke awareness in our population. Educational programs about stroke
warning symptoms as part of secondary prevention strategies for stroke patients are
needed to improve early recognition in this high-risk population, given that prior
stroke does not improve the recognition of new events.
The role and procedures of EMS in Argentina should be revised as their use did not
improve arrival times at the hospital. Also, stroke symptom recognition was associated
with the non-utilization of EMS.
Lastly, misdiagnosis by non-neurologist medical providers is concerning. Programs
to address stroke knowledge among them are needed to plan future educational interventions.
