The effectiveness of depression care management on diabetes-related outcomes in older patients.

BACKGROUND

Depression frequently occurs in combination with diabetes mellitus, adversely affecting the course of illness.

OBJECTIVE

To determine whether enhancing care for depression improves affective and diabetic outcomes in older adults with diabetes and depression.

DESIGN

Preplanned subgroup analysis of the Improving Mood-Promoting Access to Collaborative Treatment (IMPACT) randomized, controlled trial.

SETTING

18 primary care clinics from 8 health care organizations in 5 states.

PATIENTS

1801 patients 60 years of age or older with depression; 417 had coexisting diabetes mellitus.

INTERVENTION

A care manager offered education, problem-solving treatment, or support for antidepressant management by the patient's primary care physician; diabetes care was not specifically enhanced.

MEASUREMENTS

Assessments at baseline and at 3, 6, and 12 months for depression, functional impairment, and diabetes self-care behaviors. Hemoglobin A(1c) levels were obtained for 293 patients at baseline and at 6 and 12 months.

RESULTS

At 12 months, diabetic patients who were assigned to intervention had less severe depression (range, 0 to 4 on a checklist of 20 depression items; between-group difference, -0.43 [95% CI, -0.57 to -0.29]; P < 0.001) and greater improvement in overall functioning (range, 0 [none] to 10 [unable to perform activities]; between-group difference, -0.89 [CI, -1.46 to -0.32]) than did participants who received usual care. In the intervention group, weekly exercise days increased (between-group difference, 0.50 day [CI, 0.12 to 0.89 day]; P = 0.001); other self-care behaviors were not affected. At baseline, mean (+/-SD) hemoglobin A1c levels were 7.28% +/- 1.43%; follow-up values were unaffected by the intervention (P > 0.2).

LIMITATIONS

Because patients had good glycemic control at baseline, power to detect small but clinically important improvements in glycemic control was limited.

CONCLUSIONS

Collaborative care improves affective and functional status in older patients with depression and diabetes; however, among patients with good glycemic control, such care minimally affects diabetes-specific outcomes.