How Does Innovation Spread?

In a word, slowly. Our colleagues in the field of psychology tell us that human beings are incredibly resistant to change. But what about in the healthcare industry where innovation is expected and even demanded of physicians and hospitals? Thousands of clinical studies are published every year and based just on the sheer volume of clinical literature, one might assume that medicine is universally dynamic, infused with an ethical mandate to roll-out innovations as rapidly as possible. But even if we assume that a true innovation in clinical care has been identified, historical experiences suggest that the healthcare industry is as resistant to change - if not more so - than other industries.

Caused by blood clots in the brain's blood vessels, ischemic stroke is a leading cause of death and disability in the United States. Prior to the mid-1990s, there were no effective treatments for ischemic stroke. Although ischemic stroke patients arriving at the hospital would receive supportive medical care, there were no known pharmaceutical or surgical interventions proven to lyse or remove the blood clot. However, in 1996, on the strength of a study published in the New England Journal of Medicine, the FDA approved the intravenous delivery of the clot-busting tissue plasminogen activator (tPA) as the first treatment for acute ischemic stroke.

The first true therapy for ischemic stroke had been approved, the optimists sat back and waited for a dramatic spike in the use of tPA and a concomitant improvement in clinical outcomes.

However, despite tPA's FDA approval and a rash of subsequent studies confirming the drug's clinical efficacy for treating ischemic stroke, the use of tPA remained surprisingly low. Even today, only 1-5 percent of ischemic stroke patients nationally receive tPA. The reasons are many. First, to be eligible for tPA, patients must present to the hospital within three hours of stroke onset. Second, there are a host of physiological contraindications to tPA that disqualify many patients. Yet, even among patients who are eligible for tPA, the national treatment rates range from 15-20 percent.

Why aren't more eligible ischemic stroke patients receiving tPA? Innovation spreads slowly.