Timely Access to Primary Stroke Centers in the United States

Stroke, with direct and indirect costs totaling $68.9 billion, is a major primary health priority in the United States. Every 40 seconds, someone in the United States experiences a stroke, and every 3 to 4 minutes, someone dies of a stroke. Administering intravenous (IV) recombinant tissue plasminogen activator (tPA) within 3 hours of onset of symptoms is associated with a 30% greater likelihood of decreased disability compared with placebo. In selected patients, IV recombinant tPA may be safely used up to 4.5 hours after symptom onset. Despite its clinical efficacy and cost-effectiveness, only 3% to 8.5% of patients with stroke receive recombinant tPA. One limitation is timely access to care. In 2000, the Brain Attack Coalition recommended establishing primary stroke centers (PSCs). Researchers recently conducted a study to determine the proportion of the population with access to Acute Cerebrovascular Care in Emergency Stroke Systems (ACCESS). The study also examined how policy changes such as allowing ground ambulances to cross state lines and air ambulances to transport patients from the prehospital setting to PSCs would affect access to stroke care. They reported study results in Archives of Neurology [2010;67(10):1210-1218]. The researchers utilized data via the US Census Bureau, The Joint Commission, and the Atlas and Database of Air Medical Services. Validated models were used to estimate driving distances, ambulance driving speeds, and prehospital times; estimates were adjusted for population density. Access was determined by summing the population that could reach a PSC within the specified time intervals. The analysis found that if ground ambulances are not permitted to cross state lines, fewer than 22.3% of Americans (1 in 4) have access to a PSC within 30 minutes of symptom onset, 43.2% have access within 45 minutes, and 55.4% have access within 60 minutes. Among Americans ≥65 years of age, 23.7% have 30-minute in-state access to a PSC, 42.6% have 45-minute access, and 52.7% have 60-minute access; approximately 17.9 million older Americans do not have 60-minute access to a PSC. If ground ambulances were allowed to cross state lines, the increases in the percentages of the population with 30-, 45-, and 60-minute access to a PSC would increase to 22.6%, 44.2%, and 57.2%, respectively; there would still be 135.7 million Americans without access to a PSC within 60 minutes of symptom onset. Adding air ambulances to the existing ground ambulances would increase 30-minute access from 22.3% to 26.0%, 45-minute access from 43.2% to 65.5%, and 60-minute access from 55.4% to 79.3%. By combining prehospital regionalization with transport by air ambulance, the number of Americans without 60-minute access to a PSC would decrease by 50%, to 62.9 million. The analysis found wide variation in access to PSCs by state. The percentage of the population with 60-minute in-state ground access ranged from 0% (Delaware, New Mexico, North Dakota, Vermont, and Wyoming) to 100% (District of Columbia). When ground ambulances are allowed to cross state lines, access in Delaware is increased to 28.2% and in New Mexico to 1.4%; access in North Dakota, Vermont, and Wyoming remained at 0%. When ambulances cannot cross state lines, residents in <25 states have 60-minute ground access to a PSC. States in the Stroke Belt, identified by the National Heart, Lung, and Blood Institute, are Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia. In those states, access ranges from 1.9%, 4.5%, and 7.4% for 30-, 45-, and 60-minute access (Mississippi) to 25.7%, 50.6%, and 65.5% (for Georgia). States in the Stroke Belt make up nearly half (5 of 11) of the states where <25% of the residents have 60-minute in-state ground access to a PSC. In summary, the researchers noted that only about half of the population in the United States has timely access to a PSC and that use of air ambulances would increase the percentage. “Given the time-sensitive nature of interventions for ischemic stroke, future efforts to design stroke systems should consider the population perspective and should be integrated into the ongoing development of the US emergency care system as a whole.”