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AHRQ publishes new evidence reports on treatment for extremely obese individuals and other topics

A report published recently by the Agency for Healthcare Research and Quality indicates that surgery for extremely obese patients who have tried and failed to lose weight with exercise and diet may be more effective for weight reduction. It can also improve control of some obesity-related health problems such as high blood pressure and diabetes. In addition, extremely obese individuals—those who have a body mass index (BMI) of 40 or greater—often suffer from severe health problems such as heart disease, musculoskeletal disorders, and sleep apnea that limit daily activities and put their lives at greater risk.

BMI can be calculated as weight in pounds divided by inches squared and then multiplied by 703. An online BMI calculator can be found at A person who is 5 feet 8 inches tall and weighs 276 pounds has a BMI of 42, for example, and is considered extremely obese.

Roughly 60 million adults in the United States are obese, and 9 million adults are extremely obese. A BMI of 40 or greater is not the sole criterion for selecting patients who might benefit from weight-loss surgery. Of the 9 million extremely obese adults, only a small fraction, about 1.5 percent or 140,000, undergo weight-loss surgery each year in the United States.

Approximately 20 percent of those who have weight-loss surgery experience complications. Although most complications are minor, some can be serious, according to the study authors. These include nutritional deficiencies, leaks from staple line breakdown, and deep vein thrombosis. Laparoscopic procedures result in fewer wound complications and incision hernias than traditional abdominal surgery.

The scientific evidence review that was used as the basis for the new AHRQ report revealed data suggesting that weight-loss surgery, also known as bariatric surgery, may be more effective than drugs for people with BMIs of 35 to 40; however, the evidence is not strong enough to draw firm conclusions for this group of patients. In addition, the review found that Roux-en-Y gastric bypass surgery results in greater weight loss than vertical-banded gastroplasty.

The AHRQ review did not find enough evidence to draw conclusions about differences in the safety of different types of weight-loss surgery, which include adjustable gastric banding, vertical-banded gastroplasty, and biliopancreatic diversion procedures. Less than than 1 percent of patients operated on by experienced bariatric surgeons die as a result of the surgery or from complications, but the rate may be higher for less-experienced surgeons.

The evidence review also found that some prescription medicines—particularly orlistat and sibutramine, the most widely studied drugs—promote moderate weight loss when prescribed along with recommendations for dieting. The amount of weight loss directly attributable to these drugs averages less than 11 pounds, but research shows that even such a modest weight loss may decrease the occurrence of diabetes.

No weight-loss drug appears to be superior to others, and like all medications, each has side effects. The drugs have not been studied sufficiently to evaluate the risk of rare side effects, and there has not been enough research to determine the optimal time to treat obesity with drugs or how this may vary by a patient's age, sex, or race. The evidence review found that very little research has been done on either surgery or medical treatment of obesity in children and adolescents.

The report will be considered along with other information when the Medicare Coverage Advisory Committee meets on November 4, 2004, to discuss the risks and benefits of bariatric surgery in the Medicare population.

In December 2003, the U.S. Preventive Services Task Force recommended that clinicians screen all adult patients for obesity and offer or refer obese patients for intensive counseling and behavioral interventions to promote sustained weight loss. The Task Force, which is supported by AHRQ, is the leading independent panel of private-sector experts in prevention and primary care. The Task Force conducts rigorous, impartial assessments of the scientific evidence for a broad range of preventive services.

The evidence report was prepared by researchers led by Paul G. Shekelle, M.D., Ph.D., of the Southern California Evidence-based Practice Center in Santa Monica, under a contract with AHRQ (contract 290-02-0003) through AHRQ's Evidence-based Practice Center (EPC) program. The evidence review was requested by the American College of Physicians, American Academy of Pediatrics, and American Academy of Family Physicians. These and other organizations, including NIH's National Heart, Lung, and Blood Institute, contributed to the report.

Copies of Evidence Report/Technology Assessment No. 103, Pharmacological and Surgical Treatment of Obesity (AHRQ Publication Nos. 04-E028-1, summary; 04-E028-2, full report).

In addition, Managing Obesity: A Clinician Aid, a short, AHRQ-produced document that summarizes the recent obesity screening recommendations of the U.S. Preventive Health Services Task Force, as well as the key findings of the evidence report. Select for a summary of the recommendations.

In addition to the obesity report, AHRQ has several other newly published evidence reports and technical reviews. These reports and reviews were developed by AHRQ-supported Evidence-based Practice Centers. There are 13 AHRQ-supported EPCs. They systematically review the relevant scientific literature on topics assigned to them by AHRQ and conduct additional analyses when appropriate prior to developing their reports and assessments.

The goal is to inform health plans, providers, purchasers, and the health care system as a whole by providing essential information to improve health care quality. AHRQ technical reviews and EPC reports and reviews are available online and through the AHRQ Publications Clearinghouse. Select Clinical Information at the AHRQ web site to access more information.

Evidence Reports

Celiac Disease. Evidence Report/Technology Assessment No. 104 (AHRQ Publication No. 04-E029-1, summary; 04-E029-2, full report) are available from the AHRQ Publications Clearinghouse.

Community-Based Participatory Research Assessing the Evidence. Evidence Report/Technology Assessment No. 99 (AHRQ Publication No. 04-E022-1, summary; 04-E022-2, full report) are available from the AHRQ Publications Clearinghouse.

Criteria to Determine Disability Related to Multiple Sclerosis. Evidence Report/Technology Assessment No. 100 (AHRQ Publication No. 04-E019-1, summary; 04-E019-2, full report) are available from the AHRQ Publications Clearinghouse.

Economic Incentives for Preventive Care. Evidence Report/Technology Assessment No. 101 (AHRQ Publication No. 04-E024-1, summary; 04-E024-2, full report) are available from the AHRQ Publications Clearinghouse.

Islet Transplantation in Patients with Type 1 Diabetes Mellitus. Evidence Report/Technology Assessment No. 98 (AHRQ Publication No. 04-E017-1, summary; 04-E017-2, full report) are available from the AHRQ Publications Clearinghouse.

Measuring the Quality of Breast Cancer Care in Women. Evidence Report/Technology Assessment No. 105 (AHRQ Publication No. 04-E030-1, summary; 04-E030-2, full report) are available from the AHRQ Publications Clearinghouse.

Preventing Violence and Related Health-Risking Social Behaviors in Adolescents. Evidence Report/Technology Assessment No. 107 (AHRQ Publication No. 04-E032-1, summary; 04-E032-2, full report) are available from the AHRQ Publications Clearinghouse.

Technical Reviews

Closing the Quality Gap: A Critical Analysis of Quality Improvement Strategies. Technical Review No. 9.
   Volume 1. Series Overview and Methodology (AHRQ Publication No. 04-0051-1) is available from the AHRQ Publications Clearinghouse.
   Volume 2. Diabetes Mellitus Care (AHRQ Publication No. 04-0051-2) is available from the AHRQ Publications Clearinghouse.
   Volume 3. Hypertension Care (AHRQ Publication No. 04-0051-3) is available from the AHRQ Publications Clearinghouse.

Strategies to Support Quality-Based Purchasing: A Review of the Evidence. Technical Review No. 10 (AHRQ Publication No. 04-0057) is available from the AHRQ Publications Clearinghouse.

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