NEJM Issues Correction on 2005 Vioxx Study
Original trial suggested that thrombotic events diverged from placebo group only after 18 months of treatment
MONDAY, June 26 (HealthDay News) -- The New England Journal of Medicine has issued a correction to the Adenomatous Polyp Prevention on Vioxx (APPROVe) trial, a 2005 publication that suggested that thrombotic events in rofecoxib-treated patients only diverged from placebo after 18 months of treatment. However, an error in the analysis now indicates that adverse events diverged from the placebo group prior to 18 months, the authors report.
In the original analysis, the "test for proportionality of hazards used linear time rather than the logarithm of time that was specified in the Methods section," according to the correction. The abstract sentence that suggested that "during the first 18 months, the event rates were similar in the two groups," should be deleted.
A newly released report shows that "event curves begin to diverge much earlier, generally within four to six months," according to a letter by Steven E. Nissen, M.D., of The Cleveland Clinic Foundation in Ohio. The letter will be published at the same time as the correction, which will appear in the July 13 issue of the journal.
In the APPROVe trial, 32 percent of rofecoxib patients and 25 percent of placebo patients discontinued the drug due to side effects. The "premature discontinuations may have biased the Kaplan-Meier estimates of cumulative incidence and the estimated relative risk associated with treatment," according to a perspective by Stephen W. Lagakos, Ph.D.