In acute ischaemic stroke, thrombolysis with intravenous alteplase improves outcomes. However, stroke thrombolysis rates remain low by international standards and vary between centres within New Zealand.1–3 A key barrier to efficient stroke thrombolysis is poor access to experienced stroke physicians, especially in regional settings.4,5 There is little information on stroke thrombolysis services in New Zealand. Most available information has come from large urban hospitals6,7 with less insight about the provision of thrombolysis in regional centres.8 We report the results of two surveys conducted in 2011 and 2016 to gain an overview of barriers to and changes in, thrombolysis provision in New Zealand.

Methods

All New Zealand DHBs were invited to participate in two surveys five years apart (2011 and 2016) that were designed to examine various organisational aspects of stroke thrombolysis. The 2011 survey asked about the provision of thrombolysis, training of and rosters for responsible clinicians, and the use of protocols, guidelines and audit. In 2016, the questions were modified so that more detail about the issues identified in 2011 were obtained. The 2016 survey was generated on SurveyMonkey (www.surveymonkey.com) and distributed via email. Reminder emails were sent at three weeks, and any outstanding surveys conducted over the telephone at five weeks. Participants were advised that no individual DHB or hospital data were to be identified. Both surveys took 5–10 minutes to complete.

Surveys were completed at each DHB by a dedicated stroke physician, a general physician with an interest in stroke thrombolysis or in a few small hospitals where a physician was not available, by a stroke nurse specialist. DHB data were reported as that of the largest hospital in those DHBs with multiple hospitals. For stratification purposes, hospitals were divided into three groups according to the size of their DHB catchment population: large, with a population of more than 250,000 people, medium, 125–250,000 and small, less than 125,000, to enable comparison with similar DHBs. Out-of-working hours were defined as between 17:00–08:00 hours Monday through Friday, weekends and holidays. Otago and Southland DHBs were combined into the single Southern DHB after the first survey, so that 21 DHBs were surveyed in 2011 and 20 in 2016.

Results

Survey responses were returned by all DHBs. In 2016, six responses were received from hospitals other than the main DHB hospital and while results are reported by DHB, smaller hospital-specific data are reported where appropriate.

Provision of thrombolysis services

In 2016, all 20 (100%) DHBs provided routine thrombolysis for acute ischaemic stroke, compared with 18 of 21 (86%) in 2011 (Table 1). Sixteen DHBs serving 92% of the population currently provide a 24-hour service thrombolysis, compared with 13 (71%) in 2011. The increase in 24-hour provision is most marked in small DHBs, with four of the seven DHBs offering 24-hour services in 2016 compared to only two in 2011. One medium-sized DHB still only offers thrombolysis between 08:00–22:00 hours on weekdays only, and three small DHBs only do so between 08:00–17:00 hours on weekdays.

Table 1: Comparison of thrombolysis staffing and rosters by DHB size, 2011 and 2016.

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*There are eight small DHBs in 2011 and seven in 2016, corresponding to the before and after of the merging of Southland with Otago to form the single large Southern DHB.

A “Code Stroke” contact system with pre-hospital notification to acute stroke teams is currently used in 13 (65%) DHBs (Table 2). Twelve (60%) DHBs have clearly-labelled thrombolysis treatment kits in the emergency department (ED) for faster and safer alteplase access. Plain computed tomography (CT) is available 24-hours in all DHBs. CT angiogram (CTA) is offered in 18 (90%) DHBs, and is available 24-hours per day in 12 (60%). CT perfusion (CTP) is only available in three (15%) DHBs and is offered 24-hours in only one large urban hospital.

Table 2: Details of thrombolysis service provision by DHB size, 2016.

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Thrombolysis staffing and working hours

There has been an improvement in staffing levels since 2011. In 2016, the numbers of senior medical officers (SMOs) responsible for the final decision on whether or not to proceed with stroke thrombolysis ranged from a mean of 14 in large DHBs, eight in medium-sized DHBs and seven in small DHBs, a marked increase since 2011 (Table 1). During working hours, thrombolysed patients were managed in the ED by SMOs with registrars in 14 (70%) DHBs, registrars with SMO phone back-up in two (10%) large DHBs and by the SMOs alone in two (10%) small DHBs (Table 2). After hours, including weekends and holidays, SMOs supervise thrombolysis in person in eight (40%) DHBs, while a resident medical officer (RMO) does this with SMO phone back up in eight (40%) DHBs. At the time of the 2016 survey, an after-hours telestroke service pilot was being run by the Capital and Coast DHB Neurology Department for three DHBs (Hawkes Bay, Nelson-Marlborough and MidCentral DHBs).

Clinician training and exposure to thrombolysis

Thrombolysis experience increased with 57% of SMOs having treated 10 or more cases in 2016 compared to 41% in 2011, with the largest improvement seen in small DHBs (Table 1). In 2016, there were six SMOs who had undertaken stroke fellowship training, 20 whose physician training included rotations through stroke units and 23 who had participated in all-day thrombolysis courses. SMOs with such training were a minority of those on thrombolysis rosters. For example, the six stroke fellowship trained SMOs worked at five of the seven large DHBs, where there were a mean of 14 (range 5–34) SMOs on the roster. Large DHBs had a mean of 2.5 (range 0–10) SMOs who had rotated through stroke units during their training. In small DHBs, where there were a mean of seven (2–13) SMOs on the roster, a mean of two (range 0–9) SMOs had attended all-day thrombolysis courses.

Formal protocols for the management of various aspects of stroke thrombolysis were used in all 20 DHBs in 2016. These included pre-thrombolysis inclusion and exclusion criteria, administration and dosing instructions for alteplase, post-thrombolysis nursing observations and complication management. In 2011, the use of thrombolysis registers with patient audit were only used in seven (39%) of the 18 DHBs providing stroke thrombolysis. Partly in response to this low number, the National Stroke Thrombolysis Register was implemented in all 20 New Zealand DHBs in January 2015. However, in even 2016, only 11 (55%) DHBs routinely reviewed individual patients with complications in Mortality and Morbidity (M&M) meetings.

Discussion

The major finding of this study is that there has been an improvement in stroke thrombolysis service provision over the past five years. In 2016, all 20 New Zealand DHBs routinely offered stroke thrombolysis, with 16 providing a 24-hour service. The number of SMOs on thrombolysis rosters has increased, as has the numbers of SMOs who have treated 10 or more patients. There is greater use of thrombolysis protocols and audit. However, regional variations still exist with four medium and small DHBs providing thrombolysis on weekdays only due to an insufficient number of SMOs on thrombolysis rosters.

There has been a steady increase in stroke thrombolysis rates from 3% of all ischaemic stroke patients in 2009 to 6.4% in mid-20152 and 8.4% in mid-2016.9 The 2010 New Zealand Clinical Guidelines of the Management of Stroke promoted a number of quality improvement initiatives for this purpose, and which led to organisational changes in acute stroke care across most DHBs since.10 The National Stroke Network was established and monitors the stroke thrombolysis rates with a current national target of 6% of all ischaemic strokes. In January 2015, the National Stroke Thrombolysis Register was instituted with data from all New Zealand stroke patients treated with thrombolysis entered into the database on a quarterly basis. The register has allowed for regular audit with the aim of driving improvements in the numbers of patients treated and reductions in treatment time delays, and has provided a focus for an annual national stroke thrombolysis data and quality meeting. Similar registers have driven improvements in treatment rates and times.11

Most of the improvements seen since 2011 have been in small DHBs. Challenges remain in the often geographically large and rural, low population DHBs where treatment is usually delivered by staff with less case experience. Large DHBs face a parallel challenge in ensuring maintenance of clinician competency when individual physician experience is diluted by the large numbers of SMOs on thrombolysis rosters. International data suggests that service configurations providing frontline care by generalists without expert stroke-physician back-up results in low overall thrombolysis rates, excessive time-to-treatment delays, poor diagnostic accuracy, protocol violations and higher rates of complications including symptomatic intracranial haemorrhage.12–15 Employing on-site stroke-physicians in all New Zealand DHBs is not realistic due to low numbers and low population densities. There are various other ways in which these gaps are being addressed. These include the strengthening of regional networks with hub and spoke networks (a model being explored in the Northern region), and the use of 24-hour telestroke, which is being trialled in a Central Region pilot.

The use of thrombolysis protocols is now widespread, with 100% of hospitals having protocols for patient selection, alteplase dosing and the management of common complications. However, this cannot substitute for real-life thrombolysis case experience. Low patient volumes result in treating clinicians being less confident with greater risk of treatment delays and protocol violations.

This study has a number of limitations. The survey was only sent to lead stroke clinicians in each DHB and therefore data was only recorded for the largest hospital within a DHB. Several DHBs have more than one hospital and in some cases, the ‘secondary’ hospital has a drainage population larger than some small DHBs, for example, Waitakere Hospital in Waitemata DHB. This was done to keep the analysis and presentation of the results as simple as possible. Secondly, surveys offer a convenient means of reviewing clinical practices in a large number of hospitals, but the most appropriate individual within an institution may not be targeted, thus responses to a survey may not reflect actual practice.16 In both surveys, attempts were made to contact physicians with a known interest in stroke at each DHB. We did not verify responses, but made clear that no DHB would be identified. It is therefore reasonable to assume that the responses reflect the state of thrombolysis practice in New Zealand.

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