Grant: Catalyst Grant: Personalized Health Catalyst Grants

Depression screening is controversial, and the Canadian Task Force on Preventive Health Care recommends against depression screening. A major concern is that depression screening tests are not sufficiently accurate. All existing studies have used a cutoff method, where all patients who score above the cutoff on a depression screening questionnaire are considered positive screens and possible cases, whereas those below the threshold are considered negative screens. This method is not accurate, and information from actual patient screening scores is lost by dichotomizing simply into positive and negative screens. Datasets collected in primary studies are too small for developing individual risk models for depression. We will use very large datasets (e.g., > 20,000 patients) that we have synthesized for screening with three commonly used screening tests, the Patient Health Questionnaire-9 (primary care settings), the Hospital Anxiety and Depression Scale (hospital settings and medically ill), and the Edinburgh Postnatal Depression Scale (perinatal care), to develop individual risk models. We will use actual screening questionnaire scores, along with patient demographic and medical characteristics, to estimate risk compared to a gold standard diagnostic interview. Results will be used to develop an easily accessible app for use in practice.