Obesity surgery-related complications in the United States fell by 21 percent between 2001 and 2006.  These dramatic results were based on an analysis of more than 9,500 patients under age 65 who had bariatric surgery between 2001 and 2002 and between 2005 and 2006.  This study was done by the U.S. Agency for Healthcare Research and Quality.  The study revealed that complications fell even though there were more older and sicker patients having obesity surgery. During the study period, the proportion of patients over age 50 having obesity surgery increased from 28 percent to 44 percent, and the average number of underlying illnesses — such as diabetes, high blood pressure and sleep apnea — in bariatric surgery patients more than doubled.   The three main factors found to be significant causes of the decline in complications among obesity surgery patients include: increased use of laparoscopic approach, which allows surgeons to operate through small incisions; increased use of banding procedures  such as lap band; and increased surgeon experience.