Clinical versus patient-reported measures of depression in bariatric surgery

Bariatric surgery patients with mental illness may experience worse surgical outcomes compared to those without. Depression is the most prevalent mental health diagnosis amongst Americans with obesity. Accurate diagnosis and treatment is of paramount importance to mitigate perioperative risk. Unfortunately, there is no standard method to screen patients for depression prior to surgery. Our goal was to understand the relationship between traditional clinical screening tools and a novel patient-reported depression screening survey, Patient Health Questionnaire 8 (PHQ-8), in the setting of the bariatric surgery preoperative assessment.

The study included all adult bariatric surgery patients from January 2014 through June 2016. Patients who were not assessed using both the PHQ-8 and a traditional clinical depression screening were excluded from the study. There were a total of 4486 patients who met the eligibility criteria and were included in analysis. We used comparative statistics to examine the association between these screening tools and to test for contributing demographic, surgical, and socioeconomic factors.

The overall rate of clinically diagnosed depression in the study cohort was 45.6%. In comparison, 14.8% of all patients screened positive for depression using the PHQ-8. Of the patients without a traditional clinical diagnosis of depression, 10.2% screened positive for depression using the PHQ-8. This subset of undiagnosed patients was more likely to be non-white, employed, and had a higher BMI than their clinically diagnosed counterparts.

We found a higher rate of clinically diagnosed depression in our cohort compared to the general population. However, when using the validated PHQ-8 survey, the rate of depression more closely approximated the national incidence. Further, a significant proportion of patients were undiagnosed and/or misdiagnosed by current clinical assessments. Standardizing preoperative depression screening using validated patient-centered tools may prevent the consequences of untreated depression.