Venous thromboembolism rates steady despite hospital prophylaxis

Last Updated: 2015-06-15

By David Douglas

NEW YORK (Reuters Health) - Although venous thromboembolism (VTE) rates are low in hospitalized patients following colorectal surgery, the increasing use of prophylaxis seems to have little impact, according to Washington state-based researchers.

In a June 10 online paper in JAMA Surgery, Dr. Scott R. Steele, of Madigan Army Medical Center, Tacoma, and colleagues note that although VTE is an important complication of such surgery its incidence in the current era of prophylaxis is unclear.

To investigate further, the team examined Washington state data on more than 16,000 patients who underwent colorectal surgery between 2006 and 2011.

Over the study period, the use of perioperative VTE chemoprophylaxis increased significantly from 31.6% to 86.4%. In-hospital VTE chemoprophylaxis rose from 59.6% to 91.4%. A total of 10.6% were discharged on VTE prophylaxis.

VTE within 90 days was seen in 360 patients (2.2%) overall. Patients undergoing abdominal operations had higher rates than those having pelvic operations (2.5% versus 1.8%, p=0.001). Rates were similar, but nonsignificant, in patients having an operation for cancer or for nonmalignant processes (2.1% versus 2.3%).

On adjusted analysis, being older, nonelective surgery, a history of VTE, and operations for inflammatory disease were associated with increased risk of 90-day VTE.

However, despite the steady increase in chemoprophylaxis use in the perioperative and in-hospital settings, the annual VTE incidence remained low and largely unchanged, the researchers say. For example, the rate was 2.6% in 2007 and 3.0% in 2011.

In fact, the investigators say, "If nonselective perioperative and in-hospital prophylaxis is not successful in reducing rates of in-hospital VTE over time, are we placing patients at undue risk without significant benefit?"

Nevertheless, they also point out, "With almost 40% of VTE events occurring after discharge, this may represent an area for quality improvement implementation."

As Dr. Steele told Reuters Health by email, "Despite our best practices, a small percentage of patients may still develop a VTE." Prophylaxis efforts have improved greatly in the preoperative and perioperative in-hospital settings, but "in the post-discharge setting, we likely need a much larger randomized prospective study involving patients with similar risk profiles evaluating extended prophylaxis versus none to demonstrate whether or not this is a benefit."

In an accompanying editorial, Drs. Christian de Virgilio and Jerry J. Kim of Harbor-UCLA Medical Center in Torrance, California, note that the VTE rate is among factors that will be taken into consideration when judging possible reduction of Medicare payments to hospitals as mandated by the Patient Protection and Affordable Care Act.

Thus, Dr. de Virgilio told Reuters Health by email, "Pegging surgical reimbursements to outcomes puts U.S. surgery on a potential slippery slope, as emerging data suggest that VTE rates may not be an ideal quality indicator."

The National Institute of Diabetes and Digestive and Kidney Diseases supported this research. The authors reported no disclosures.

SOURCE: http://bit.ly/1F8OjId and http://bit.ly/1Lb6RQf

JAMA Surg 2015.