The relationship of guideline-concordant depression treatment and patient adherence to oral diabetes medications.

BACKGROUND

Many patients with diabetes experience depression, yet it is unclear if the treatment of depression in diabetic patients is concordant with national guidelines, and whether appropriate antidepressant use is associated with better diabetes self-care behaviors.

OBJECTIVES

The purpose of this study was to (1) determine whether antidepressant medication use for managed care enrollees with type 2 diabetes was concordant with The Agency for Healthcare Research and Quality depression treatment guidelines; and (2) examine the relationship between guideline concordance and oral diabetes medication adherence.

METHODS

Retrospective analyses were conducted using medical/pharmacy claims for 2001 from a managed care organization in the midwestern United States. Subjects were adults with type 2 diabetes treated with oral medications only. The subjects were divided into 3 groups: (1) guideline-concordant users of antidepressants; (2) those who received antidepressants not in concordance with the guidelines; and (3) nonusers of antidepressants. Antidepressant users were determined to be in concordance with the acute phase treatment guidelines if they filled at least 90 days supply of antidepressant drugs within 118 days of the first fill. Adherence to diabetes medications was measured by the medication possession ratio. A 1-way analysis of variance with Scheffe's test was used to compare the antihyperglycemic medication possession ratio across the three groups.

RESULTS

One hundred eighty-two (12.5%) of the 1454 subjects initiated treatment with antidepressants. Eighty-nine (48.9%) of the 182 antidepressant users were in concordance with the acute phase treatment guidelines. Subjects with subconcordant antidepressant use had a lower mean diabetes medication possession ratio than those with either guideline-concordant use or no use (F=14.3, P<.01).

CONCLUSION

Over half of the diabetic patients initiating treatment for depression did not receive therapy in concordance with the Agency for Healthcare Research and Quality guidelines. Patients whose antidepressant use was not concordant with the guidelines were also less adherent to diabetes medications.