Prevalence of Depression in Patients with Type 2 Diabetes (T2D) in Quebec

Background A higher incidence of depression has been observed among T2D patients. The burden of this comorbidity is not known in Quebec. Objectives To evaluate the annual prevalence of depression among new antidiabetic drug (OAD) users in Quebec in 2000 to 2008 and to identify associated factors. Methods Prevalent cases of depression among new OAD users aged ≥18 were identified using administrative databases from the public health insurance in Quebec by one of the following criteria: 1) 1 inpatient service for depression claimed, 2) 2 outpatient services for depression claimed in the same calendar year, 3) 1 outpatient service for depression claimed with 1 claim for an antidepressant prescription in the same calendar year. Factors associated with depression were assessed using logistic regression. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. Results Of the 181 801 new OAD users, 7441 had depression (4.1%) in 2000 to 2008. Each year, the proportion of depression was higher among females than among males (4.8% versus 2.9% in 2008) and among 18 to 44 years (7.4% versus 2.7 % among ≥65 years in 2008). Other factors associated with depression were residence (OR: 1.26, CI: 1.18 to 1.34 urban versus rural), specialty of the practitioner (OR: 0.77, CI: 0.69 to 0.86 endocrinologist versus general practitioner) and category of insured (OR 1.72, CI 1.17 to 2.53 financial assistance versus elderly group). Conclusions Depression is a common comorbidity in patients with T2D newly treated with OADs in Quebec. Clinicians should pay special attention to younger patients, women and people living in cities and with financial assistance.