Reports of Increased Blood Clots Following Surgery May Indicate Higher Quality Hospital Care

Research has found that higher quality hospitals and those hospitals that regularly check surgical patients for blood clots tend to report higher blood clot rates than lower quality facilities and hospitals that do not regularly check patients for clots, according to Reuters Health.

Some policymakers have suggested that the increased incidence of blood clot reporting in surgical patients should be a measure of a hospital’s quality, or rather, issues with that facility’s quality; however, research suggests that increased clotting cases may not be indicative of a lower quality facility, Reuters Health reported. “Usually, if you have a higher complication rate, you’re not doing a good job, but in this case it’s actually the opposite,” Dr. Karl Bilimoria, the study’s lead author from Northwestern University and Northwestern Memorial Hospital in Chicago, told Reuters Health.

The researchers, writing in The Journal of the American Medical Association (JAMA), pointed out that hospitals and physicians looking for blood clots usually find more of them; therefore, a hospital with a higher number of clotting incidences might give a false impression of lower quality, Reuters Health indicated.

The blood clots—venous thromboembolisms (VTEs)—are seen as preventable if hospitals are able to identify at-risk patients and put those patients on medications meant to stop blood from clotting, Reuters Health explained.

According to JAMA, the research was examining if so-called “surveillance bias”—the increased intensity of a search for a condition being tied to the likelihood that the condition would be found—influences reported rates of VTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE). Bilimoria pointed out that clotting following surgery occurs because the body is in a “clotting mindset”  as it attempts to stop all bleeding. “Blood clots after surgery are an important complication,” he added. “They can have severe consequences, and it can be fatal if the blood clot travels to the lung,” he noted, Reuters Health reported.

“However, measuring VTE rates may be flawed because of surveillance bias, in which variation in outcomes reflects variation in screening and detection, or ‘the more you look, the more you find’ phenomenon…. Hospitals that are more vigilant and perform more imaging studies for VTE may identify more VTE events, thus resulting in paradoxically worse performance on the VTE outcome measure,” according to background information in the article, JAMA wrote.

For the study, Bilimoria and colleagues reviewed data from 2,786 hospitals and 954,926 Medicare patients discharged following surgery between 2009 and 2010. In one analysis, the team compared hospitals they deemed high quality with those deemed low quality, according to Reuters Health. A higher quality facility was seen as one that conducted many surgeries and organ transplants and was also a teaching hospital.

The so-called “high-quality hospitals” were likelier to comply with blood clot prevention methods, but also had a higher proportion of surgery patients diagnosed with clots, the researchers discovered. Higher quality hospitals reported about 6.4 blood clots per 1,000 surgery patients; by contrast, lower quality hospitals diagnosed 4.8 clots per 1,000 patients, Reuters Health wrote. The hospitals that conducted the most blood clot testing discovered more than twice as many blood clots as hospitals that conducted the fewest tests.

JAMA indicated that the study is being released early to coincide with the American College of Surgeons 2013 Annual Clinical Congress.