NATIONAL HARBOR, MD. – Psychological screening prior to bariatric surgery is not effective for identifying who will do poorly after the procedure, but it can identify patients who are at risk for less weight loss and likely to benefit from additional support, according to one of the largest studies designed to evaluate the predictive accuracy of this screening. The results were presented at Obesity Week 2017.
“Psychological evaluations should not be used to exclude patients, because we do not appear to be very good at predicting who does well,” said Nina E. Boulard, PhD, a psychologist who currently performs preoperative psychological screening of bariatric surgery candidates at Eastern Maine Medical Center, Bangor. Rather, “our evaluations identify those who need to be followed more closely so we can intervene early when patients struggle,” she said at an annual meeting presented by the American Society for Metabolic and Bariatric Surgery and The Obesity Society.
The two primary outcomes of interest were the ability to predict postsurgical mental health issues and the ability to predict difficulty in complying with behavioral changes. Percent excess weight loss (EWL) was also monitored. For mental health screening, the protocol included clinical interviews augmented with standardized testing, such as the Minnesota Multiphasic Personality Inventory-2-Restuctured Form (MMPI-2-RF). Patients were placed into five risk categories: low, low-moderate, moderate, moderate-high, and high.
For compliance, the patient evaluation was based primarily on interviews capturing self-reports of adherence to presurgical dietary and other lifestyle recommendations. Patients were also asked about eating behaviors, such as binge eating, and history of sexual abuse and attention-deficit/hyperactivity disorder and other neurodevelopmental issues.
The psychological screening report is provided to the surgeon, who ultimately decides whether patients go on to surgery. In this analysis, relatively few high-risk patients were included because these patients, such as those with active psychosis, uncontrolled binge eating, or severe depression, were excluded from surgery and therefore did not generate postsurgical follow-up data.
As has been reported by others, Dr. Boulard reported that no single standardized test or clinical variable was an effective predictor of “who will and will not struggle” psychologically after surgery. However, after adjusting for age, gender, presurgery weight, diabetes history, and surgery type, several variables were associated with reduced proportion EWL. These included anxiety (P = .02), ADHD (P = .01), and prior hospitalization of a psychological indication (P less than .05). History of sexual abuse was predictive of reduced percentage EWL 1 year but not 2 years after surgery.
“So, what this tells us is the clinical interpretation of the big picture might be important,” Dr. Boulard commented.
The presurgical psychological screening was not predictive of compliance, a result that Dr. Boulard labeled as “surprising.” She speculated that because weight loss in the first 2 years after bariatric surgery is relatively uniform, longer follow-up, such as 5 years, might be needed to capture the impact of patients predicted to have poor compliance.
Importantly, percent EWL remained high even among patients with risk factors associated with mental health challenges after surgery, according to Dr. Boulard. She stressed that even those with less weight loss “did not do poorly.” Rather, the relative differences in postsurgical weight loss for those who were predicted to struggle versus those who were not was “a matter of degrees.”
While Dr. Boulard acknowledged a prospective study using a standardized psychological screening protocol would be appropriate to validate the findings of this study, the study results have already changed practice at her institution.
“We are following the at-risk patients more closely, so we can intervene quickly if there are issues after surgery,” Dr. Boulard explained. The question raised by this study is, “can we bring them [patients at higher risk] to a higher level of response so they are just as successful” as those without risk factors identified in psychological screening.
Dr. Boulard reports no financial relationships relevant to this topic.