Berlin prehospital or usual delivery of acute stroke care – Study protocol

Abstract

Rationale Prehospital stroke care in specialized ambulances increases thrombolysis rates, reduces alarm-to-treatment times, and improves the prehospital triage. Preliminary analyses suggest cost-effectiveness. However, scientific proof of better functional outcome compared to usual care is still lacking. Aim To prove better functional outcomes after deployment of the Stroke Emergency Mobile compared to regular ambulances. Sample size estimates A sample size of 686 patients will be required in each arm (Stroke Emergency Mobile group vs. regular care) to detect a difference regarding the primary outcome with 80% power at a two-sided significance level of 0.05. Methods and design This is a pragmatic, prospective study with blinded outcome assessment. Primary outcome will be functional status as defined by modified Rankin Scale score three months after the incident event. We will include cerebral ischemia patients within a predefined catchment area in Berlin, Germany. The study population consists of patients who might be candidates for acute recanalizing treatments, with onset-to-alarm time ≤4 h, symptoms not resolved at time of ambulance arrival, and able to walk without assistance prior to the qualifying incident. About 45% of Stroke Emergency Mobile dispatches are expected to be handled by regular ambulances, since Stroke Emergency Mobile will be already in operation creating the control group. Primary outcome Functional outcome after three months measured by the modified Rankin Scale over the entire range. Discussion The results will inform decision makers on the effectiveness of Stroke Emergency Mobile.

Thrombo-Inflammation in Cardiovascular Disease: An Expert Consensus Document from the Third Maastricht Consensus Conference on Thrombosis

“…153,154 Evidence for effectiveness on clinical outcomes is expected soon. 155,156 As discussed in "EVs and thrombin generation in AIS," stroke is a highly heterogeneous disease when considering clinical presentation, severity, imaging, location of the lesion, and functional outcome which are captured by numerous scores, scales, and classification systems. Probably, the most widely known is the modified Rankin Scale, a seven-category ordinal outcome focused on the functional outcome after stroke.…”

Functional stroke outcomes after mobile stroke unit deployment – the revised protocol for the Berlin Prehospital Or Usual Delivery of acute stroke care (B_PROUD) part 2 study

“…If ascertainment is uncertain, the clinical documentation is submitted to an independent adjudication committee for blinded judgement. Additionally, patients with [1] stroke mimics receiving thrombolysis will be included in a sensitivity analysis together with the primary study population, and patients with [2] intracerebral hemorrhage presenting within 6 h from symptom onset will be analyzed as a companion study population.…”

“…Yet, despite a non-significant trend for disability-free survival at 3 months in favor of the MSU care group in a registry-based analysis [7,8], definite scientific proof of a positive effect of MSU treatment on functional outcome of stroke patients is still lacking. Thus, we started the B_PROUD study on February 1, 2017 [1]. In the meantime, the STEMO service in Berlin was extended to three simultaneously operating STEMOs covering almost the entire Berlin city area.…”

Impact of your results: Beyond the relative risk

“…In some fields, there is little confusion surrounding this aspect, as standard practice dictates a fixed time period. For example, most stroke studies involve an assessment of functional outcome at the time point of 3 months post‐stroke, making the interpretation and comparison of reported NNT findings unambiguous across different studies 4. However, in the context of chronic disease treatment and variable follow‐up time, failure to explicitly mention the time frame could result in a misleading representation of the NNT and inaccurate comparisons.…”