Depression diagnoses and antidepressant use in primary care practices: a study from the Practice Partner Research Network (PPRNet).

BACKGROUND: We examined the pharmacologic management and follow-up of adults with newly diagnosed depression, and the use of antidepressants among patients not diagnosed with depression in primary care practice. A total of 389 physicians in 39 practices in the Practice Partner Research Network (PPRNet), a national network of primary care physicians provided data for the study.
METHODS: We performed a retrospective cohort study for the year 1996 using demographic, contact, diagnosis, and prescription data available in the December 1997 PPRNet database. We identified patients with new diagnoses of depression from the problem lists in the electronic medical record. Psychopharmacologic agents prescribed within 5 days of the diagnosis, follow-up contacts within 6 months of the diagnosis, and diagnoses of patients prescribed antidepressants without a new diagnosis of depression were also identified. We performed descriptive analyses for all practices and for individual practices.
RESULTS: During 1996, there were 149,327 active adult patients in the 39 participating practices. Of the 131,141 patients without a history of depression or antidepressant prescription, 2103 (1.6%) had a new diagnosis of depression in 1996. Incidence among the 39 practices ranged from 0.4% to 4.0%. Forty-nine percent of the newly diagnosed patients received an antidepressant prescription within 5 days of diagnosis; 81% of the prescriptions were for selective serotonin reuptake inhibitors. Ninety percent of the patients prescribed antidepressants had at least one contact in the 6 months after diagnosis (mean = 5.3 contacts). One third of the patients who had not begun antidepressants within 5 days of their diagnoses started taking one by the end of 1996. Among the 149,327 active patients, 6.3% received a prescription for an antidepressant in 1996. More than 40% of these patients had never been diagnosed with depression.
CONCLUSIONS: Our study highlights the high prevalence and wide interpractice variations of diagnosing depression and prescribing antidepressants in primary care. Follow-up of patients newly diagnosed with depression was common and consistent with published guidelines. Opportunities for increased detection and treatment of depression exist in approximately half of the study practices.