Patients with depression and poorly controlled diabetes, coronary heart disease, or both have an increased risk of adverse outcomes and high health care costs. We conducted a study to determine whether coordinated care management of multiple conditions improves disease control in these patients.

We conducted a single-blind, randomized, controlled trial in 14 primary care clinics in an integrated health care system in Washington State, involving 214 participants with poorly controlled diabetes, coronary heart disease, or both and coexisting depression. Patients were randomly assigned to the usual-care group or to the intervention group, in which a medically supervised nurse, working with each patient's primary care physician, provided guideline-based, collaborative care management, with the goal of controlling risk factors associated with multiple diseases. The primary outcome was based on simultaneous modeling of glycated hemoglobin, low-density lipoprotein (LDL) cholesterol, and systolic blood-pressure levels and Symptom Checklist–20 (SCL-20) depression outcomes at 12 months; this modeling allowed estimation of a single overall treatment effect.

As compared with controls, patients in the intervention group had greater overall 12-month improvement across glycated hemoglobin levels (difference, 0.58%), LDL cholesterol levels (difference, 6.9 mg per deciliter [0.2 mmol per liter]), systolic blood pressure (difference, 5.1 mm Hg), and SCL-20 depression scores (difference, 0.40 points) (P<0.001). Patients in the intervention group also were more likely to have one or more adjustments of insulin (P=0.006), antihypertensive medications (P<0.001), and antidepressant medications (P<0.001), and they had better quality of life (P<0.001) and greater satisfaction with care for diabetes, coronary heart disease, or both (P<0.001) and with care for depression (P<0.001).

As compared with usual care, an intervention involving nurses who provided guideline-based, patient-centered management of depression and chronic disease significantly improved control of medical disease and depression. (Funded by the National Institute of Mental Health; ClinicalTrials.gov number, NCT00468676.)