Symptom prevalence differences of depression as measured by BDI and PHQ scales in the Look AHEAD study

Objective: To compare depressive symptomatology as assessed by two frequently used measures, the Beck Depression Inventory (BDI-1A) and Patient Health Questionnaire (PHQ-9). Methods: Investigators conducted a cross-sectional secondary analysis of data collected as part of the follow-up observational phase of the Look AHEAD study. Rates of agreement between the BDI-1A and PHQ-9 were calculated, and multivariable logistic regression was used to examine the relationship between differing depression category classifications and demographic factors (ie, age, sex, race/ethnicity) or comorbidities (ie, diabetes control, cardiovascular disease). Results: A high level of agreement (κ = 0.47, 95% CI (0.43 to 0.50)) was found in the level of depressive symptomatology between the BDI-1A and PHQ-9. Differing classifications (minimal, mild, moderate, and severe) occurred in 16.8% of the sample. Higher scores on the somatic subscale of the BDI-1A were significantly associated with disagreement as were having a history of cardiovascular disease, lower health-related quality of life, and minority racial/ethnic classification. Conclusions: Either the BDI-1A or PHQ-9 can be used to assess depressive symptomatology in adults with overweight/obesity and type 2 diabetes. However, further assessment should be considered in those with related somatic symptoms, decreased quality of life, and in racial/ethnic minority populations.