In Reply We appreciate Spies and colleagues for their thoughtful comments. We agree that we should follow randomized trials, and certainly, without meticulous attention paid to study design, the conclusions reached by observational studies can be marred by bias. However, not all questions related to the care of patients with deep vein thrombosis (DVT) can be addressed by randomized trials, and not all findings of randomized trials are reproduced in “real-world” settings (external validity). Because the acute mortality in these patients is very low, it is difficult, if not impossible, to assess this difference by randomized trials. Prior to our study,1 safety outcomes for catheter-directed thrombolysis (CDT) have been inconclusive, and many physicians were concerned about the potential fatal bleeding complications of this therapy, which is used to prevent a nonfatal, albeit debilitating, condition of postthrombotic syndrome.
Bashir R, Zack CJ. For Deep Vein Thrombosis, Follow the Randomized Trials—Reply. JAMA Intern Med. 2015;175(4):653-654. doi:10.1001/jamainternmed.2014.8177