Problems with measuring compression device performance in preventing deep vein thrombosis

The purpose of this article is to discuss issues related to the use and performance of mechanical compression devices in preventing deep vein thrombosis (DVT), such as graduated compression stockings (GCSs) and pneumatic compression devices (PCDs). While various studies have shown mechanical compression to be effective against DVT, the adequacy of the performance of these devices has not been conclusively determined. One reason for this inconclusiveness is small sample bias in which the results of many studies are open to a considerable chance of error. Another problem is that the studies may not be appropriate designed to measure device effectiveness and be free of bias. In addition, new methods of DVT prophylaxis are forcing a reexamination of what it means for a device to be “effective.” Finally, the prevention of DVT is not likely to occur if the patient declines to comply with a prescribed treatment. Compliance is particularly bad with GCSs and some compliance comparisons on PCDs have suffered from failing to control for potentially confounding factors. As such, more and better studies need to be performed on these devices.