Who Best to Create a Sense of Urgency for Acute Stroke Treatment? Commentary on "Neurohospitalists Improve Door-to-Needle Times for Patients With Ischemic Stroke Receiving Intravenous tPA".

In the 17 years since the efficacy of intravenous tissue plasminogen activator (tPA) for acute ischemic stroke was first established, we have struggled to develop the infrastructures and systems of care that are necessary to deliver this therapy as quickly and efficiently as possible. Speed matters. Although delays in presenting to the emergency department account for most of the unrealized potential of thrombolysis, the time from when a patient arrives in the emergency department to when the tPA infusion begins—the door-to-needle time—presents a more readily accessible target for hospital-level interventions. Pooled data from 6 randomized trials and analyses of large observational data sets consistently show that faster door-to-needle times are associated with better patient outcomes. In fact, each 15-minute decrease in door-to-needle time is associated with a 5% lower odds of in-hospital mortality. Therefore, the American Heart Association: Target Stroke initiative has set a specific goal of raising the percentage of patients treated within 60 minutes from the current level of 29% to over 50%. Precisely how to actually achieve this goal involves evaluating a variety of factors, but certainly one important consideration is ensuring that appropriate staffing is available for these neurological emergencies. In this issue of The Neurohospitalist, Bhatt and Shatila examine the impact of neurohospitalists on door-to-needle times for acute ischemic stroke. The study includes data from 107 consecutive patients treated with intravenous (IV) tPA at 2 community hospitals between July 2009 and September 2011. The study was a natural experiment of sorts: halfway though the study period, coverage for acute stroke calls from the emergency department changed from a rotating schedule of 4 community neurologists with shared inpatient and outpatient responsibilities to a neurohospitalist model staffed by 2 inpatient-based neurologists. Occasional weekend coverage continued to be provided by locums tenens and community neurologists. The primary finding was that among patients treated with IV thrombolysis for stroke, 51% (24 of 47) of those evaluated by neurohospitalists were treated in 60 minutes or less, compared with 15% (9 of 60) of those evaluated by nonneurohospitalists—a difference that may be due, at least in part, to the greater likelihood that a neurohospitalists is in hospital for an emergency in-person consultation. Bhatt and Shatila are generally careful not to assert a causal relationship between a neurohospitalist’s involvement and faster door-to-needle times, with the notable exception of the article’s title. Such caution is warranted. First, there are likely to be unmeasured confounders and secular trends at play. For example, a t test comparing the mean performance of the 2 groups may obscure a secular trend of improved door-toneedle times over time. Other analytic methods such as interrupted time series analysis are often used to mitigate this possibility in other quality improvement studies. Next, relevant details on how the availability of neurohospitalists would actually impact the response time are unavailable. These details would be especially important to understand and evaluate because the acute stroke response involves interactions between