Patient selection and index date assignment for Study 1. (A) Flow chart of selection of patients with diabetes for comparison of affective disorder (AD) risk with subjects who were free of both diabetes and AD. Subjects aged 20 years or over with a diagnosis of type 2 diabetes mellitus (T2DM) recorded more than once within 1 year or who had used any oral anti-hyperglycemic agent (OAA) for at least 3 months during the period 1996 to 2007 regardless of insulin usage, were evaluated. (B) Follow-up of AD onset; patients with diabetes mellitus (DM), who did or did not use oral anti-diabetic agents (OAA). were matched with diabetes-free counterparts, who had the same index dates as the DM diagnostic date.
Wahlqvist et al. BMC Medicine 2012 10:150 doi:10.1186/1741-7015-10-150