Results: Objective: To compare rates of depression diagnosis in adults with and without diabetes, with careful control for number of primary care visits.
Methods: Adults with incident (N=2,932) or prevalent (N=14,144) diabetes were matched to non-diabetes controls based on (i) age and gender, or (ii) age gender and number of outpatient visits. Logistic regression was used to predict depression diagnosis in each diabetes cohort relative to matched non-diabetes controls.
Results : Prevalent diabetes patients with few primary care visits were significantly more likely (odds ratio = 1.46, 1.19-1.80) to have a new depression episode than control group (i) , but this relationship diminished and then reversed as patients accrued more than 10 PC visits (odds ratio = 0.95, .77-1.17). Prevalent DM patients with few primary care visits were more likely (odds ratio = 1.32, 1.07-1.63) to have a new depression episode than those in control group (ii), but this relationship diminished and reversed as patients accrued more than 4 PC visits (odds ratio = .99, .80-1.23). Similar results were observed in incident DM patients and their matched non-diabetes controls.
Conclusions: These results demonstrate little or no increase in risk of a new depression episode in incident or prevalent diabetes patients relative to those without diabetes after controlling for number of outpatient visits. Studies showing such an association may have inadequately adjusted for exposure to the medical care system. Prevalent diabetes patients had less depression than age- gender- and visit-matched controls, when visits exceeded 6 visits a year.