Critical analysis of results: weight loss and quality of data.

Difficulties associated with outcome assessment of operations performed for treatment of morbid obesity include lack of uniform standards for reporting results, failure to account for the response of related medical problems to weight loss, and lack of actuarial data for patients greater than or equal to 45 kg overweight. The purpose of this report is to critically analyze various methods of outcome assessment including the 5-y postoperative weight loss results of vertical banded gastroplasty and Roux-en-Y gastric bypass. Weight loss after these procedures usually reaches a nadir between 18 and 24 mo postoperatively. Mean percent excess weight loss at greater than or equal to 5 y ranged from 48% to 74% after gastric bypass and from 50% to 60% after vertical banded gastroplasty. Medical problems are almost invariably improved with satisfactory weight loss. Surgery remains the mainstay in treatment of morbid obesity because of the nearly 100% failure rate of nonoperative treatment in these patients.