Response by Farooq et al to Letter Regarding Article, “Relationship Between Femoral Vascular Closure Devices and Short-Term Mortality From 271 845 Percutaneous Coronary Intervention Procedures Performed in the United Kingdom Between 2006 and 2011: A Propensity Score–Corrected Analysis From the British Cardiovascular Intervention Society”

We thank Secemsky et al for their constructive remarks on our study1; and comments that are equally applicable to all observational studies. We fully concur that residual confounding factors may be a potential explanation for our study findings, demonstrating vascular closure devices (VCDs) to be associated with a minor short-term (30-day) mortality impact, a fact that was openly acknowledged throughout the article. We also fully recognize that methods to minimize confounding in registry data should be utilized wherever possible, recognizing that registries by their inherent design can never fully account for residual confounding, no matter how robust the analysis performed.2 In addition, it should be highlighted that the propensity score correction adopted during our study was extremely comprehensive, with all important recorded confounding factors included. With this backdrop, comments stating that residual confounding to be the most likely explanation for our study findings appear unjustified. As demonstrated in our study, the …