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Studies examine rates of morbid obesity and bariatric surgery and risk of death after the surgery

An estimated 6 million people in the United States were considered morbidly obese in 2001. Morbid obesity is defined as having a body mass index of 40 kg/m2 or more or of 35 kg/m2 with medical problems related to obesity. Bariatric surgery remains the most effective therapy for certain patients with morbid obesity. Bariatric surgery reduces the size of the stomach to a tiny pouch and usually bypasses the small intestine so that stomach contents empty directly into the large intestine. About 75 percent of patients lose 50 to 75 percent of their body weight within 2 years and keep it off.

Two studies supported by the Agency for Healthcare Research and Quality (T32 HS13833) examined regional differences in morbid obesity and bariatric surgery rates and risk factors for patient death after surgery. The first study concluded that regional bariatric surgery rates do not reflect the rates of morbid obesity in individual regions. The second study found that men, older people, those insured by Medicaid, and those who required re-operation were more likely to die in the hospital after the surgery. Both studies are briefly discussed here.

Poulose, B.K., Holzman, M.D., Zhu, Y., and others (2005, July). "National variations in morbid obesity and bariatric surgery use." Journal of the American College of Surgeons 201, pp. 77-84.

According to this study, national estimates indicate that bariatric surgery rates do not parallel the burden of morbid obesity by region or age. Researchers identified 69,490 patients who underwent bariatric surgery from the 2002 Health Care Cost and Utilization Project National Inpatient Sample. Regional rates of people with morbid obesity were estimated using the Centers for Disease Control and Prevention 2002 Behavioral Risk Factor Surveillance System. The researchers estimated regional rates of bariatric surgery based on the number of people in each region who were obese and potentially eligible for the surgery.

Over 5 million (nearly 2 percent) of people in the United States were morbidly obese in 2002; 60 percent were women, and 63 percent of these women were between the ages of 18 to 49. The rates of bariatric surgery procedures per 100,000 morbidly obese individuals ranged from a low of 139 in men aged 60 years and older in the Midwest to a high of 5,156 in women aged 40 to 49 years in the Northeast.

For both men and women, bariatric surgery rates in the West and Northeast were nearly 2 to 4 times higher than they were in the South, respectively. Rates in the Midwest were similar to those in the South. However, the rate of morbid obesity was lowest in the Northeast and West and highest in the Midwest and South among people aged 60 years or younger. The researchers suggest that these findings underscore the need to improve access to bariatric surgery in regions with higher rates of morbid obesity and lower rates of the surgery.

Poulose, B., Griffin, M.R., Moore, D.E., and others (2005, July). "Risk factors for post-operative mortality in bariatric surgery." Journal of Surgical Research 127, pp. 1-7.

From 0.5 to 1.5 percent of patients who undergo bariatric surgery die in the hospital after the operation. Being male, older than 39 years, insured through Medicaid, or requiring re-operation during the initial hospitalization places a person at a higher risk of dying postoperatively than other bariatric surgery patients, according to this study. The researchers identified 54,878 adults who underwent bariatric surgery from the 2001 Nationwide Inpatient Sample (NIS) of U.S. hospital discharges. They examined the effect of sex, age, insurance status, and need for re-operation on postoperative mortality.

The average length of hospital stay (LOS) was nearly 4 days and overall mortality after the surgery was 0.4 percent. The average LOS of those who died was nearly 18 days. After adjusting for coexisting medical problems and demographics, the researchers found that men were twice as likely as women to die in the hospital after bariatric surgery. Patients aged 39 and older were nearly 3 to 4 times more likely to die than younger patients. Patients insured through Medicaid had nearly 5 times the risk of dying than privately insured patients, and those requiring re-operation were at 22 times higher risk of dying.

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