The PASTA trial provides evidence that incremental improvements in thrombolysis delivery are unlikely to be achieved through isolated use of more sophisticated pre-hospital assessments. It is more likely that large scale co-ordinated approaches across service boundaries will achieve a step change in performance.
The unexpected combination of thrombolysis, health and economic outcomes observed among PASTA patients led us to consider whether structured handover of additional information and/or a multidisciplinary checklist could improve the selection of patients for thrombolysis, particularly in hospitals with lower levels of specialist availability. As no harm was observed through the PASTA intervention, implementation should be considered in stroke services where there is an unavoidably low level of specialist availability for thrombolysis decision-making.
The PASTA trial process evaluation suggested that ongoing assistance with patient care by paramedics post handover did not make a significant difference to emergency stroke treatment. Although this was valued personally by some paramedic interviewees and the extra time did not cause decompensation of ambulance service response times, it was the hardest part of the pathway to initiate and there was little hospital enthusiasm because only limited actions were possible. However, both paramedics and hospital staff supported provision of feedback, which could be readily incorporated into the exchange of information during a structured handover.
Modelling outputs from WP2 informed widely disseminated recommendations for services and clinicians produced by NHS England,4 NICE97 and Oxford Academic Health Science Network.25 These strongly support the evidence that IAT should be routinely delivered, and that the largest increase in provision in the short term will be through a ‘drip and ship’ service configuration. An increase in IAT provider centres could enable more efficient delivery of treatment, and, for the most remote populations, air ambulance transport appears to be a viable approach, although three of the nine HEMS indicated that additional funding and/or organisational changes would be required. Although clinical effectiveness was considered paramount, where travel time would be > 45 minutes, participants in our BWS study were willing to forego some health benefits to access a less expert service locally. Commissioning decisions should probably, therefore, not be made solely based on changes to maximise health gains from IAT.