A nationwide population-based study suggests that the rate of complications 6 months after bariatric surgery is higher than previous research suggested, and that resultant hospital readmissions increase health care costs.
“A clear way to reduce the costs and improve outcomes of bariatric surgery is to address the high rate of postoperative complications,” said William E. Encinosa, Ph.D., and his colleagues at the Agency for Healthcare Research and Quality in Rockville, Md.
The study of insurance claims data across 49 states in 2001 and 2002 found that nearly 40% of bariatric surgery patients experienced a complication within 180 days of being discharged, while 22% of patients had a complication prior to discharge (Medical Care 2006;44:706–12). That represents an 81% increase in complications over the 6 months after surgery, compared with the 10%–20% range found in the literature, the authors said.
The five most common complications were dumping syndrome (19.5%), complications of the anastomosis (12.3%), abdominal hernia (7%), infection (5.7%), and pneumonia (4.1%).
However, the study is weakened by its reliance on claims data, Dr. Matthew M. Hutter said in an interview. “Reliance on claim forms data makes it difficult to determine what a complication is,” he explained. As the authors themselves conceded, visits for nutritional issues are especially difficult to sort out. “If you're seeing a patient because of a nutritional issue, it might be because he has a nutritional issue or it might be because you're concerned that he might develop one. So you wouldn't want to say that the responsible surgeon who is just following up on his patient within the first 180 days and monitoring a nutritional issue necessarily [indicates] a complication,” said Dr. Hutter, who is director of the Center for Clinical Effectiveness in Surgery at Massachusetts General Hospital, Boston.
According to the study, 18.2% of the patients with postoperative complications were readmitted, visited the emergency department, or were treated as outpatients. The most costly aspect of bariatric surgery was readmission: Total 6-month risk-adjusted inpatient and outpatient health care payments were 140% higher for those with 180-day readmissions with complications. Total 6-month risk-adjusted health care payments were $65,031 for those with 180-day readmission, compared with $27,125 for those without readmission.
For their data source, the authors used the MarketScan Commercial Claims and Encounter Database created by the Medstat Group for 2001 and 2002. The database covered approximately 5.6 million enrollees under the age of 65 in employer-sponsored benefit plans for 45 large employers.
Patients with more than one comorbidity were more likely to have a complication diagnosed during readmission, an outpatient hospital visit, or an office visit. Although there was no difference between men and women, older individuals had a 26% higher risk-adjusted complication rate than did those aged 18–39 years.
The authors cited the following limitations of their study: the inability to track deaths outside the hospital, which accounted for the low death rate of 0.2%; the lack of information regarding patients' body mass indexes; and, in their risk-adjusted regressions, the inability to control for surgeon and hospital bariatric volume. “Hospitals with more experience may have fewer complications,” they said. “However, in a subset of 625 surgeries in which we had bariatric volume, we found no link between volume and the risk of complication after adjusting for age, sex, and number of comorbidities.
“As patients, payers, and … physicians increasingly consider gastric bypass surgery for treatment of morbid obesity, this study provides representative information regarding complications and clinical risks after surgery for the privately insured, relatively young population. The risk of a complication and readmission was significant for both clinical outcomes and costs, which provides incentive for intervention and improvement,” the investigators concluded.
While applauding the authors for shedding more light on this topic, Dr. Hutter said future research “should compare apples to apples. In this study, we don't know what to compare the numbers to.”
He added that in addition to trips to the emergency department and hospital visits, “perhaps we also should look at real outcomes for patients, such as weight reduction and loss of comorbidities including diabetes, hypertension, sleep apnea, and hypercholesterolemia, and compare them with a group of untreated obese patients, and for a period of time longer than 180 days.”