Telemedicine in acute stroke care: the TESSA model

Abstract

We conducted a retrospective controlled study to assess the safety and effectiveness of intravenous thrombolysis via videoconferencing, followed by patient transport to a specialized stroke unit. Between 2006 and 2009, 47 stroke patients were treated in peripheral hospitals in the county of Salzburg in Austria by intravenous thrombolysis via telemedicine; 304 patients who were treated with intravenous thrombolysis at a stroke unit served as the control group. The mean age of the patients was 67 years in the telemedicine group and 71 years in the control group. Haemorrhagic bleeding occurred in 6.4% of the telemedicine group compared to 7.6% of the control group. The mean onset-to-needle time was 113 min in the telemedicine group and 122 min in the control group (P = 0.263). At three-month follow-up, 47% of the patients in the telemedicine group had good functional outcomes (mRS, dichotomized analysis 0–1) versus 43% in the control group (P = 0.694). The overall mortality at three-month follow-up was 19% in the telemedicine group and 13% in the control group (P = 0.248). Telemedicine can be used to support regional areas with little experience in delivering intravenous thrombolysis, thus raising the standard of stroke care and minimizing inequalities.

Introduction

In industrialized countries stroke is the third largest cause of death after cardiovascular diseases and cancer, and a major cause of permanent disability.¹ Patients who receive care in a specialized stroke unit are more likely to survive and make a good recovery compared to patients treated in general medical wards.² For acute ischaemic stroke patients, intravenous thrombolysis treatment with tissue plasminogen activator (tPA) within three hours of the onset of stroke symptoms has been shown to reduce subsequent dependency, morbidity and mortality.^3,4 The problem is, however, that most stroke patients do not have access to stroke unit care and intravenous tPA, since these are both primarily offered in academic stroke departments. The main reasons for this are a lack of experts (especially in non-urban areas), financial factors and delays in hospital admissions. A large number of stroke patients are unable to access a hospital with the appropriate facilities within the three-hour treatment window for intravenous tPA.⁵

There has been growing interest in the role that telemedicine could play in improving the quality of stroke management. The primary benefit of a telemedicine system is that areas with insufficient neurological services can be supported by a stroke expert through a telephone or video link. Telemedicine interventions in acute stroke care may improve quality and processes in stroke care and increased use of intravenous tPA. Other putative advantages are reductions in costs (avoidance of patient transfer), improvements in stroke education and better efficiency in implementation of rehabilitation services.^6–10

We have explored the safety and effectiveness of intravenous tPA via telemedicine followed by patient transfer to a specialized stroke unit. A further goal is to evaluate the quality of care/service. The hypothesis is that a videoconference-based telestroke system can safely and effectively increase the use of intravenous thrombolysis in areas with insufficient neurological experience. After telethrombolysis the patients are transferred to a specialized stroke unit, which provides full coverage of guideline driven stroke care and the benefit of specialized stroke unit therapy.

Methods

A retrospective controlled study was conducted. The telemedicine group consisted of patients who were treated with intravenous thrombolysis via videoconferencing between 2006 and 2009. There were five regional hospitals connected to a stroke unit via telemedicine. The control group consisted of patients who were treated with intravenous thrombolysis at the specialized stroke unit.

The inclusion criteria were: first time ischaemic stroke patients of age 18 years or older, treated with intravenous thrombolysis within 4.5 hours. The exclusion criteria were: a previous stroke history, patients arriving 24 hours after stroke onset to the stroke unit, patients with severe disabilities (NIHSS score over 25 at admission).

Data collection

A list of different variables and outcome measurements was constructed, based on a systematic review of telemedicine in acute stroke care.⁹ Data on the telemedicine group was mainly collected through the Austrian Stroke-Unit-Registry (Gesundheit Österreich GmbH), patients’ case notes and telestroke sheets. The control group was identified through the Austrian Stroke-Unit-Registry. A telestroke sheet was used for each videoconference involving among others a criteria list for intravenous thrombolysis, patient name, date of birth, National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS). Telestroke patients treated with thrombolysis were either identified through the telestroke sheets or through an admission registration book at the stroke unit. Every patient treated at the stroke unit was recorded in this book. With the patient number it was possible to identify the patient in the hospital clinical information system and in the Austrian Stroke-Unit-Registry in order to collect patient relevant information. Patient data was downloaded from the Austrian Stroke-Unit-Registry.

The Austrian Stroke-Unit-Registry has been administered since 2003 by the Gesundheit Österreich GmbH as an initiative of the Federal Government of Austria.¹¹ In 2008, 26 out of the 32 Austrian stroke units participated in the Austrian Stroke-Unit-Registry. The main objective of the registry is quality assurance and quality improvement of stroke-treatment in stroke units¹².

Outcome measures

There were two main outcome measures. First, for effectiveness, we used mortality, neurological status using NIHSS and mRS. Second, for safety, we used mortality, complications during transfer and complications during hospital stay.

To analyse the quality of care/service the following secondary outcome measurements were used: length of stay, haemorrhage as a complication, discharge destination and processes of service (onset-to-needle and onset-to-stroke unit). At the three-month follow-up, patient status, living situation and mRS were analysed.

Statistical analysis

The statistical analysis followed the intention-to-treat principle. Binary variables were analysed using a chi²-test (Fisher's Exact Test). Continuous variables were analysed with a t-test (two-tailed). Descriptive statistics were used for the mRS (percentage allocation) and a dichotomized analysis with a chi²-test was also used for the mRS. Statistical analysis was performed using a standard package (SPSS).

Intervention

The telestroke system in Salzburg (TESSA) is based on a high-quality videoconference system linking five regional hospitals in Salzburg County with a specialized stroke unit. The specialized stroke unit is a part of the clinic of neurology at the Christian-Doppler-Clinic, Salzburg City. The regional hospitals are situated 20–129 km from the specialized stroke unit and only one of those hospitals has a neurological department.

Remote video-examination of patients was performed using a videoconferencing system. A VSX 7000 system (PolyCom, Inc.) was installed in the regional hospitals and a VSX 6000 system was installed in the specialized stroke unit. Physicians in the emergency departments initiated the consultation by contacting the on-call stroke neurologist in the stroke unit when a possible candidate for intravenous thrombolysis was identified. A specialized stroke team in the stroke unit provided 24-h support to the regional hospitals. All patients were examined by a stroke neurologist who completed a NIHSS, reviewed tPA eligibility, viewed computed tomography (CT) scans of the head and provided recommendations on stroke management. All hospitals had the ability to send CT and MRI scans by teleradiology.

After telethrombolysis the patient was transferred either by ambulance or helicopter to the stroke unit for further monitoring and surveillance. This system allowed stroke patients in regional areas full availability to guideline-driven stroke care including neurosurgery and neuroangiography interventions.

Results

In total 49 patients were treated with intravenous thrombolysis via telemedicine between 2006 and 2009. Two patients were excluded due to a previous stroke history. 399 stroke patients were treated with intravenous thrombolysis between 2006 and 2009 at the specialized stroke unit. A total of 304 remained as controls due to correlations and plausibility testing and the inclusion/exclusion criteria; 70 patients were excluded due to a previous stroke history; and 12 patients were excluded due to severe impairment at admission (NIHSS > 25). Two patients aged under 18 years were excluded. Six patients who were treated with intravenous thrombolysis after 4.5 hours were excluded. One patient was excluded due to incomplete data and four patients were excluded because of arriving later than 24 h after stroke onset at the stroke unit.

The baseline characteristics of the patients are summarized in Table 1. The mean age was 67 years (SD 14) in the telemedicine group and 71 years (SD 16) in the control group. There were no significant differences between the groups when comparing risk factors, except for smokers. There were more smokers in the telemedicine group: 32% versus 16% in the control group (P = 0.032). Ninety-four percent of the patients in the telemedicine group compared to 87% in the control group (P = 0.33) had good clinical function (mRS dichotomized analysis, 0–1) before stroke onset (P = 0.48). The performance of the hospitals in predefined measures for the quality of acute stroke care are shown in Table 2. The mean length of stay at the stroke unit was 6.4 days (SD 5.0) in the telemedicine group versus 5.5 days (SD 4.6) in the control group (P = 0.26). In total 12 stroke patients died during hospitalization, four (9%) in the telemedicine group and eight (3%) in the control group (P = 0.056). The majority of the patients were discharged home, 14 (31%) in the telemedicine group compared to 79 (26%) in the control group. More patients in the control group (17%) were discharged to another department than patients in the telemedicine group (9%), but this was not significant (P = 0.20). More patients in the control group (21%) were discharged to a neurological acute care or intensive care unit compared to patients in the telemedicine group (7%) (P = 0.024). In the telemedicine group 17 patients (38%) were transferred back to the consulting hospital.

Table 1

Baseline data

	Telemedicine	Control	P value
No. of patients included	47	304
No. of patients excluded	2	95
Mean age, years (SD)	67 (15)	71 (16)	0.062¹
Proportion of females, %	34	50
Comorbidities:
Diabetes mellitus	8 (n = 46)	57 (n = 296)	0.84²
Hypertension	29 (n = 46)	218 (n = 299)	0.22²
Myocardial infarction	2 (n = 47)	23 (n = 300)	0.55²
Atrial fibrillation	17 (n = 45)	107 (n = 287)	>0.999²
Hypercholesterolaemia	21 (n = 46)	135 (n = 294)	>0.999²
Other cardiac disease	13 (n = 47)	54 (n = 294)	0.17²
Current tobacco use	11 (n = 34)	44 (n = 270)	0.032²
No or minor disability³	44 (n = 47)	265 (n = 304)	0.33²

¹ t-test (two-tailed)

²Fisher's Exact Test (two-tailed)

³Dichotomized analysis, no or minor disability defined as a mRS score of 0–1

Table 2

Indicators for quality of acute stroke care

	Telemedicine	Control	P value
Mean length of stay in stroke unit, days (SD)	6.4 (5.0) (n = 43)	5.5 (4.6) (n = 304)	0.26¹
Discharge destination:	(n = 47)	(n = 304)
Died in hospital	4	8	0.056²
Home	14	79	0.48²
Nursing home	0	6	>0.999²
Geriatric department or home for the elderly	2	70	0.003²*
Early rehabilitation	1	25	0.23²
Other department	4	52	0.20²
Neurological acute care bed or intensive care unit	3	62	0.024²
Transfer back to consulting hospital	17	N/A
Data missing	2	2
Onset to stroke unit (min.) mean (SD)	231 (57) (n = 44)	108 (72) (n = 280)	<0.001¹
Onset to needle (min.) mean (SD)	113 (40) (n = 42)	122 (47) (n = 277)	0.26¹

¹ t-test (two-tailed)

²Fisher's Exact Test (two-tailed)

N/A = not applicable

The mean onset-to-stroke unit time was longer in the telemedicine group, at 231 min (SD 57) compared to the control group at 108 min (SD 72) (P < 0.001). The mean onset-to-needle time was slightly shorter in the telemedicine group compared to the control group but not significant, 113 min (SD 40) versus 122 min (SD 47) (P = 0.26).

After telethrombolysis all patients were transferred to a specialized stroke unit. No complications were reported during transportation.

Neurological examination was performed using the NIHSS and mRS (Table 3). At hospital admission before intravenous thrombolysis the mean NIHSS was 9.9 (SD 5.2) in the telemedicine group and 10.4 (SD 5.9) in the control group (P = 0.73). After intravenous thrombolysis and transfer to the specialized stroke unit the mean NIHSS in the telemedicine group was 9.1 (SD 7.2). At discharge the mean NIHSS was 6.0 (SD 7.3) in the telemedicine group compared to 6.8 (SD 7.9) in the control group (P = 0.50).

Table 3

Patients' neurological function: mean values for NIHSS and mRS (SD)

	Telemedicine	Control	P value
NIHSS: At admission¹	9.9 (5.2) (n = 19)	10.4 (5.9)¹ (n = 304)	0.73²
At stroke unit admission	9.1 (7.2) (n = 47)	10.4 (5.9)¹ (n = 304)
At stroke unit discharge	6.0 (7.3) (n = 43)	6.8 (7.9) (n = 292)	0.50²
mRS: (dichotomized)³
At stroke unit discharge	18 (38%) (n = 47)	98 (32%) (n = 302)	0.51⁴
At three-month follow-up	14 (47%) (n = 30)	76 (43%) (n = 179)	0.69⁴

¹The telemedicine group were admitted to the regional hospital and the control group were admitted directly to the stroke unit.

² t-test (two-tailed)

³Good functional outcome defined as a score of 0–1

⁴Fisher's Exact Test (two-tailed)

At stroke unit discharge there were no significant mRS differences between the groups. Thirty-eight percent of the telemedicine group had good functional outcomes at discharge compared to 32% in the control group (P = 0.51) using a dichotomized analysis.

The mRS at the three-month follow-up showed no significant differences between the groups using a dichotomized analysis. In total 47% of the patients in the telemedicine group had good functional outcome at three months compared to 43% in the control group (P = 0.69). There were in-hospital complications in 11 (23%) patients in the telemedicine group compared to 66 (22%) patients in the control group (P = 0.85). In the control group haemorrhage bleeding was the most common in-hospital complication: 7.6% compared to 6.4% in the telemedicine group.

In total, complete follow-up data was obtained from 30 (64%) patients in the telemedicine group and from 188 (72%) patients in the control group. At the three-month follow-up, five (17%) patients had died in the telemedicine group compared to 30 (16%) in the control group (P > 0.999). The overall mortality was 19% (9/47) in the telemedicine group and 13% (38/304) in the control group (P = 0.25). Most patients were living at home alone or with a family member/friend (Table 4).

Table 4

Patient status and living situation at three-month follow-up

	Telemedicine (n = 47)	Control (n = 304)	P value
Drop outs (%)	17 (26%)	116 (28%)
Carried out	30 (64%)	188 (72%)	0.29¹
In-hospital mortality	4 (9%)	8 (3%)	0.094¹
Mortality during follow-up	5 (17%)	30 (16%)	>0.999¹
Overall mortality	9 (19%)	38 (13%)	0.25¹
Living situation:	(n = 25)	(n = 150)
At home alone	5 (20%)	16 (11%)	0.19¹
At home with family member or friend	18 (72%)	118 (79%)	0.45¹
Retirement home or care home	2 (8%)	16 (11%)	>0.999¹

¹Fisher's Exact Test (two-tailed)

Discussion

The purpose of telestroke is to transfer expert knowledge and experience of stroke management to areas with insufficient neurological services. Telemedicine networks usually seek to establish connections between remote locations and provide specialist support through different types of videoconferencing and/or telephone systems. Most of these systems allow the transfer of radiology images and clinical data.

Comparing results from randomized clinical trials on intravenous thrombolysis with results from telethrombolysis studies gives an indication of the safety of the telestroke intervention. The mortality rate and mRS at three-month follow-up from clinical trials and telethrombolysis studies is shown in Table 5. The mortality rate at three-month follow-up in the National Institute of Neurological Disorders and Stroke rt-PA stroke study group (NINDS study) was 17%. A dichotomized analysis of the mRS showed that 39% of the patients had a good functional outcome at three months.¹³ In the Canadian Alteplase for Stroke Effectiveness Study (CASES) the mortality rate after three months was 22% and 37% of the patients had good functional outcome.¹⁴ Only two telethrombolysis studies reported on mortality and neurological clinical outcomes at three-month follow-up.^15,16 In one study the overall mortality rate at three-month follow-up was 11% and 38% of the patients had good functional outcome (mRS dichotomized analysis).¹⁵ In another telethrombolysis study with a small population the overall mortality rate in the videoconferencing group was 39% (n = 12) and 30% (n = 9) had good functional outcome (mRS dichotomized analysis) compared to 12% (n = 3) and 32% (n = 8) in the telephone group.¹⁶ These results are similar to the three-month follow-up results of the telemedicine group in the present study. The overall mortality at three-month follow-up was 19% and 47% of the patients had a good functional outcome (mRS dichotomized analysis).

Table 5

Safety of tPA treatment (3 h window)

		TEMPiS (telemedical group)¹⁵	Meyer¹⁶
	TESSA	TEMPiS (telemedical group)¹⁵	VC	TC	NINDS¹³	CASES¹⁴
Number of tPA-treated patients	47	170	31	25	312	1135
Median age (years)	72	71	N/A	N/A	67	73
Median NIHSS at admission	N/A	12	N/A	N/A	14	14
mRS (0–1) at 3 months (%)	47	38	30	32	39	37
Overall mortality at 3 months (%)	19	12	39	12	17	22

VC = Videoconferencing, TC= Telephone consulting, N/A= not applicable

Different outcome analysing processes of intravenous delivery were identified in the literature. The mean onset-to-needle time reported in the literature ranged from 122–165 min,⁹ which is slightly longer than the results from the present study (mean 113 min). A possible explanation for this result may be the efficient patient transport system and good communication between health-care personnel. The median length of hospital stay (stroke unit) in the TESSA group was five days. In other telestroke networks the median length of stay ranged between 5–12 days.⁹

The present study had several limitations. It was a retrospective controlled study where the data was mainly collected from a stroke unit quality register. Retrospective studies are subject to recall bias and the risk of incomplete documentation. Before intravenous thrombolysis, the NIHSS score was only available in 40% of the cases and information regarding mRS was missing. Inappropriate documentation and infrequent use of the telestroke sheet was the main reason for this situation. The drop out rate at three-month follow-up was quite high: 26% in the telemedicine group compared to 28% in the control group. One reason for the high drop out rate may be the date chosen for downloading data from the Austrian Stroke-Unit-Registry (20 January 2010), since three-month follow-up data was not available for patients treated between 20 October 2009 and 31 December 2010.

In conclusion, telethrombolysis administration via videoconference, followed by patient transport to a stroke unit seems to be a safe and effective part of stroke management. Patients treated with intravenous thrombolysis via videoconferencing had similar health outcomes at hospital discharge and at three-month follow-up compared to those treated with thrombolysis in a specialized stroke unit. The TESSA model provides stroke patients in regional settings with better access to intravenous thrombolysis and the added benefit of specialized stroke unit therapy.

Footnotes

Acknowledgement

We are grateful to Associate Professor Claudia Wild (Ludwig Boltzmann Institute for Health Technology Assessment, Vienna) for support and advice in the preparation of the paper.

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