Background: Few weight loss surgery trials have evaluated the changes in health-related quality of life (HRQOL) relative to obese individuals not participating in weight loss interventions. In a prospective study at a bariatric surgery practice, we evaluated the 2-year changes in HRQOL in gastric bypass patients compared with 2 severely obese groups who did not undergo surgical weight loss.
Methods: A total of 308 gastric bypass patients were compared with 253 individuals who sought but did not undergo gastric bypass and 272 population-based obese individuals using the weight-related (Impact of Weight on Quality of Life-Lite) and general (Medical Outcomes Study 36-item Short-Form Health Survey) HRQOL questionnaires at baseline and 2 years of follow-up.
Results: The percentage of weight loss was 34.2% for the gastric bypass and 1.4% for the no gastric bypass groups, with a .5% gain for population-based obese group. Both measures of HRQOL showed greater improvements for the gastric bypass group, even after controlling for baseline differences. Effect sizes for changes in physical and weight-related HRQOL were very large for gastric bypass, but small to medium for the 2 comparison groups. Effect sizes for changes in the psychosocial aspects of HRQOL were moderate to very large for gastric bypass, but small for the 2 comparison groups. Of the gastric bypass patients, 97% had meaningful improvements in the Impact of Weight on Quality of Life-Lite total score compared with 43% of the no gastric bypass group and 30% of the population-based obese group.
Conclusion: Dramatic improvements had occurred in weight-related and physical HRQOL for gastric bypass patients at 2 years after surgery compared with 2 severely obese groups who had not undergone surgery. These results support the effectiveness of gastric bypass surgery in improving patients' HRQOL.