Grant: Project Grant

Major depression is common among Canadians. Effective interventions are available, but most depressed Canadians do not receive adequate care. Depression screening, which involves using questionnaires to identify people who may have unrecognized depression is a way to improve the condition. However, it is not recommended in Canada's main healthcare guidelines due to concerns that screening tools are not accurate enough. Often, primary studies only publish results for cutoff scores that work well in a particular group of people. Also, existing screening methods do not consider patient risk factors such as age, sex, care setting, and medical diagnoses, which may be associated with depression. In this project, we will combine original patient data from published studies that used PHQ-9 as a screening tool to create a very large database that can be used to determine more accurate ways to identify patients with depression. The proposed research will provide accurate, unbiased estimates of diagnostic accuracy for PHQ-9, incorporating individual patient characteristics, which has not been done previously. Results will be used to develop and test improved depression screening and management programs and to make better decisions for individual patients.