Later in December, spurred by growing concerns raised by other studies about risks associated with Celebrex, NIH also reviewed the ADAPT study data.
NIH reached a different conclusion: The study should be stopped. This dramatic step was taken, according to an NIH news release, to protect the safety of participants because the data "indicated an apparent increase in cardiovascular and cerebrovascular events among the participants taking naproxen when compared with those on placebo."
How Risky Was Naproxen?
To make sense of the NIH announcement, readers need answers to two basic questions:
• What are the "events" that occurred more frequently among naproxen users?
• How much more often did these events occur?
Both the official NIH announcement and a related press release by the FDA were remarkably sparse in details and failed to provide answers to either of these questions. As of this writing, virtually no one outside NIH, the ADAPT study team and possibly the FDA knows which specific events prompted the announcement or how often these events occurred.
• Risk of what? NIH halted the ADAPT study because more "cardiovascular and cerebrovascular events" occurred among patients taking naproxen than those taking placebo.
But what does that term mean? Unfortunately, the definition of the term was never released.
"Cardiovascular and cerebrovascular events" could refer to a slew of outcomes varying widely in importance. At one extreme, such "events" might refer to death from stroke or heart attack. But they could also refer to nonfatal heart attacks and strokes, some serious, some mild. Or episodes of chest pain. Or mini-strokes -- known medically as transient ischemic attacks -- which are generally mild and short-lived, and leave no permanent effects. Or even changes on an EKG test or a finding on an MRI scan that never produced symptoms.
All we know is that the events in question represent some combination of such incidents and perhaps others as well. The point is that not all events are equally important.
