Four of every 10 obesity surgery patients develop a complication, such as a hernia, within 6 months of leaving the hospital, according to a new study by HHS’ Agency for Healthcare Research and Quality. The study is the most extensive to date on post-surgical complications from obesity operations based on insurance claims data.

The researchers found that the complication rate among non-elderly obesity surgery patients with private insurance increased by 81 percent following hospital discharge -  from 21.9 percent while they were still hospitalized to 39.6 percent by the end of the 180-day study period.

“Obesity surgery is helping thousands of Americans who have not succeeded at losing weight reduce their risk of diabetes and other life-threatening diseases, but this study shows how important it is for patients to consider the potential complications when they make the decision to undergo the procedure,” said AHRQ Director Carolyn M. Clancy, M.D. “The study also should give clinicians information that will help them make improvements in the procedure and post-surgical care.”

The five most common complications were dumping syndrome, which includes vomiting, reflux, and diarrhea (nearly 20 percent); anastomosis complications (complications resulting from the surgical joining of the intestine and stomach), such as leaks or strictures (12 percent); abdominal hernias (7 percent); infections (6 percent); and pneumonia (4 percent). The overall death rate for entire the 180-day postoperative period studied was low -  0.2 percent.

Complications from obesity surgery also increased costs. Medical care spending averaged $36,542 for obesity surgery patients who experienced a complication up to 180 days after surgery, including their initial hospital stay; spending for patients without complications averaged $25,337. In addition, medical care spending for patients who had to be readmitted because of a complication during the 180-day period averaged $65,031 compared with $27,125 for those who did not have to be hospitalized again.

Most studies of complications from obesity surgery, also known as bariatric or weight-loss surgery, have been limited to those that occur before hospital discharge or at the most, up to 30 days post-discharge. As noted, the new study extends the observation period up to 180 days -  6 months -  after hospital discharge.

AHRQ’s William Encinosa, Ph.D., Didem Bernard, Ph.D., and Claudia Steiner, M.D., M.P.H., also analyzed differences between 30-day and 180-day post-operative complication rates. They found that 10.8 percent of patients who had not experienced a complication within 30 days did so in the following 150 days. The four types of complications that increased the most during this period were anastomosis complications (such as intestinal leaks), marginal ulcers, abdominal hernia, and dumping.

During this same 30-day versus 180-day period, the proportion of patients who had to be readmitted to hospitals with complications increased by 50 percent -  from 4.8 percent to 7.2 percent.

The researchers also studied 44 types of conditions that can occur in patients following major surgery, regardless of the type of operation, such as complications of surgical procedure, intestinal obstruction, gastrointestinal disorders, abdominal pain, chest pain, and nutritional disorders. Readmissions of post-obesity surgery patients for these conditions increased from 6.5 percent to 10.6 percent between 30 and 180 days.

In addition, the study team analyzed visits to emergency rooms and office doctors by obesity surgery patients for the 12 types of complications specific to obesity surgery and for the 44 general post-operative conditions, differences in complication rates for banding and gastroplasty versus gastric bypass surgery, and differences by age groups.

Findings were based on claims for hospital care and outpatient care for 5.6 million enrollees under age 65 in employer-sponsored health plans for 45 large employers in 49 states for 2001 and 2002. The claims data included information on 2,522 bariatric procedures.

For details, see “Healthcare Utilization and Outcomes after Bariatric Surgery,” in the August 2006 issue of the journal Medical Care.

Agency for Healthcare Research and Quality (AHRQ)