Evaluation of expectations and knowledge in bariatric surgery patients

Preoperative psychosocial evaluations of bariatric surgery candidates primarily focus on screening for psychiatric co-morbidities. However, the role of weight loss expectations and knowledge about surgery can also influence patients' postoperative behavior. The purpose of this study was to investigate preoperative patient knowledge and expectations about postoperative weight loss.

Data on the knowledge and expectations were extracted from a database of psychosocial evaluations of 334 bariatric surgery candidates. Expectations were measured by patient report of the expected pounds to be lost. Knowledge was operationalized using the University of Virginia Bariatric Knowledge Scale, a 22-item multiple choice scale, that assesses knowledge about medical, nutritional, and psychosocial components related to bariatric surgery. The data were analyzed using frequencies, descriptive statistics, and analysis of variance.

The data on weight loss expectations from 217 preoperative patients indicated that, compared with the average weight loss data presented in published reports, 65% of patients overestimated the degree of weight loss and only 25% of patients maintained accurate expectations of weight loss. Knowledge data on the nutritional, medical, and behavioral components of the surgery were available for 96 patients. The items frequently answered incorrectly included expected weight loss and the utility of surgery in increasing the ability to make changes in diet and exercise. The mean body mass index differences were observed to determine the accuracy of weight loss expectations

The results of our study have shown that a significant number of bariatric surgery patients present with misconceptions about weight loss. The preoperative psychosocial evaluation can be used as an intervention to use psychoeducation, cognitive restructuring, and behavioral interventions to improve patients' knowledge and expectations.