Post-operative venous thromboembolisms (VTE) are often used as a metric to determine hospital quality, but a new study in JAMA has found that this may be a poor measure, Reuters reports. The study looked at 2,786 hospitals, deemed either high quality or low quality hospitals based on surgeries and education, and 954,926 patients who underwent surgery between 2009 and 2010. Researchers found that high quality hospitals reported 6.4 VTEs per 1,000 surgeries, whereas low quality hospitals reported only 4.8 per 1,000 surgeries. The numbers may not represent the actual number of clots that occurred, but rather may manifest the efficiency of the hospital in post-operative care and followup. Health care providers, thus, urge the public not to rely on VTE occurrence as an indication of hospital quality.