Severe Presentation Shaped the Early Pathway in Intracerebral Hemorrhage
Among patients brought by emergency medical services to 195 Get With The Guidelines-Stroke hospitals, intracerebral hemorrhage arrived with a heavier clinical burden than acute ischemic stroke. The cohort included 195,659 patients treated between January 1, 2015, and June 30, 2024, with 31,464 cases of ICH and 164,195 cases of acute ischemic stroke. Median age was 74 years, just over half of the cohort was female, and the neurologic deficit was far more severe at presentation in ICH: the median NIH Stroke Scale score was 14 compared with 6 in ischemic stroke. The absolute standardized difference of 0.694 signals a large baseline separation between the two groups, and that gap matters at the bedside because stroke severity often drives the speed and intensity of triage, imaging, and escalation of care.
ICH is the stroke subtype most likely to prompt immediate concern for airway compromise, hematoma expansion, and rapid neurologic decline. Those risks help explain why process metrics cannot be read in isolation; a patient with a devastating hemorrhage may prompt a different clinical response than a patient with a milder ischemic deficit even when both enter through the same emergency system.
The ED Clock Ran Differently After Adjustment for Stroke Severity
On simple demographic adjustment, ICH had slightly higher odds of reaching ED physician assessment within 10 minutes, with an adjusted odds ratio of 1.08. The same pattern appeared for brain imaging ordering within 20 minutes, where the demographic-adjusted odds ratio was 1.09. At first glance, those results suggest that hemorrhagic stroke may trigger a faster front-end response.
The picture changed once the models accounted for medical history, presenting factors including NIHSS, and hospital characteristics. After that fuller adjustment, the association reversed: ICH was linked to lower odds of physician assessment within 10 minutes, with an adjusted odds ratio of 0.94, and lower odds of an initial brain imaging order within 20 minutes, with an adjusted odds ratio of 0.91. The reversal is clinically important because it suggests the raw advantage disappeared once the greater severity of hemorrhage and the care environment were brought into the model. In practical terms, the front door of the stroke system may appear efficient for ICH, but the apparent speed is partly explained by the fact that these patients arrive sicker.
This is not a trivial statistical correction. Severe deficits can sharpen triage urgency, but they also introduce complexity: airway concerns, fluctuating consciousness, blood pressure instability, anticoagulant exposure, and the possibility of rapid deterioration all demand parallel work before the first imaging order is placed. The result is a process that may look rapid in unadjusted comparisons while still reflecting a heavier clinical workload in the hemorrhage pathway.
Prehospital Delay Remained a Central Problem for Ischemic Stroke
The clearest temporal change in the cohort came on the prehospital side. Median last known well to arrival time increased by 32.5% for acute ischemic stroke, rising from 151 to 200 minutes, with a statistically significant trend. That shift reinforces a long-standing emergency neurology problem: ischemic stroke is often defined not by what happens in the ED, but by how long patients remain outside it.
The physiologic logic is straightforward. Unlike ICH, where abrupt neurologic collapse may force immediate recognition, ischemic stroke can present with subtler findings that family members, bystanders, or patients themselves may delay in recognizing. Time lost before EMS activation compresses every downstream treatment window, especially for thrombolysis and thrombectomy eligibility. The study’s temporal trend suggests that even in a modern stroke system spanning nearly a decade, prehospital delay in AIS remained stubbornly persistent.
One sentence captures the operational tension: the system can only move as fast as the patient reaches it.
Why Severity Adjustment Changed the Interpretation
The contrast between the demographic-only and fully adjusted models is the core analytic lesson. Without accounting for NIHSS and other clinical and hospital factors, ICH looked faster in the ED. Once severity and context entered the model, the apparent advantage eroded and then inverted. That pattern argues against interpreting raw process metrics as a simple measure of system performance across stroke subtypes.
Hospital workflows are not uniform machines. A hemorrhage patient with depressed mental status may move quickly to assessment yet still encounter delays related to stabilization, imaging coordination, blood pressure control, and decisions about reversal therapy or neurosurgical consultation. In ischemic stroke, a less dramatic initial exam can create different bottlenecks, especially when symptom onset is unclear or the diagnosis is not immediately obvious. Comparing those two pathways without severity adjustment risks confusing case mix with quality.
The data also fit the broader reality that stroke systems are built around time-sensitive detection, not just time-sensitive treatment. EMS prenotification, door-to-physician assessment, and rapid imaging all depend on recognition of stroke symptoms before irreversible injury advances. Hemorrhage and ischemia strain those mechanisms in different ways, and the same metric can mean something different depending on the subtype.
What Stroke Systems Can Take From This Cohort
This multicenter cohort offers a large real-world view of how ICH and AIS move through emergency care. It shows that ICH patients arrive with substantially more severe neurologic deficits, and that this severity materially alters how process metrics should be interpreted. It also shows that prehospital delay remains an enduring obstacle in ischemic stroke, where median time from last known well to arrival worsened over the study period.
For clinicians and stroke program leaders, the practical message is to avoid assuming that one subtype is inherently “faster” than the other based on raw ED timestamps. Severity, presentation, and hospital context reshape those numbers. A hemorrhage with a low NIHSS may not behave like a hemorrhage with coma-level impairment, and an ischemic stroke with vague symptoms may not trigger the same urgency as a dense hemiparesis or aphasia.
The study does not answer every operational question. It does not show whether the timing differences translated into better functional outcomes, nor does it resolve which specific hospital workflow elements most strongly drove the adjusted results. It does, however, make one point impossible to ignore: stroke timeliness metrics are tightly linked to case mix, and any quality assessment that ignores that fact can misread the emergency care pathway.