MARCO ISLAND, FLA. — An intervention significantly increases depression-free days and improves physical functioning in the elderly—even 12 months later, Wayne J. Katon, M.D., reported at the annual meeting of the Academy of Psychosomatic Medicine.
New 2-year data from the Improving Mood—Promoting Access to Collaborative Treatment for Late Life Depression (IMPACT) study show that the clinical benefits of the intervention persist well beyond the initial 1-year treatment period.
“We saw improvements in functioning, pain, and overall quality of life,” said Dr. Katon, a psychiatrist at the University of Washington, Seattle. “We were surprised at that the extent of the benefit in year 2, which was equal to the benefit we found in year 1.”
In addition, the intervention proved cost effective at most of the sites. (See box.)
An estimated 10%–20% of older primary care patients meet the criteria for depression, and the percentage increases to up to 25% with chronic illness. But few depressed elderly patients receive appropriate care because of the burden of comorbidities, poor physical function, and often “an understanding” that they are depressed because of those comorbidities, said Dr. Katon, professor, vice chair, and director of the division of health services and psychiatric epidemiology at the university.
An initial report on IMPACT—a multicenter study of 1,801 depressed older adults—had shown that 45% of the 906 patients randomized to the intervention group had a 50% or greater improvement in depressive symptoms at 12 months (JAMA 2002;288:2836–45). In contrast, only 19% of the 895 patients randomized to usual care showed the same level of improvement.
The researchers recruited patients from 18 primary care clinics in five states. The participants were 66% female and 24% nonwhite, and all were 60 years or older (mean age 71). Many met criteria for major depression (17%), dysthymia (30%), or both (53%). Participants had a mean of 3.2 chronic illnesses, which included chronic pain, osteoarthritis, incontinence, and diabetes.
“A lot of these people would not be admitted into other depression studies because of the extent of their comorbidities,” Dr. Katon said.
Participants randomized to the intervention group had access to a dedicated depression care manager. This manager provided education, behavioral activation, support of antidepressant therapy (prescribed by the patients' primary care physicians), or brief psychotherapy using the Problem Solving Treatment in Primary Care protocol. Depression care managers tracked outcomes using the depression module of the Patient Health Questionnaire (PHQ-9) and adjusted treatment accordingly.
“Stepped care allowed us to add an antidepressant if needed or to add psychotherapy as needed,” Dr. Katon explained.
Physicians for patients in the usual care group were only told that the patient met criteria for depression or dysthymia. Physicians in the usual care arm could start patients on antidepressants or refer for psychotherapy or medication.
Patients were assessed at baseline and at 3, 6, 12, and 24 months. By 1 year, the intervention group was more likely to get some antidepressant treatment (odds ratio 2.98) and report more satisfaction with depression care (OR 3.38). Intervention patients got better more quickly over the 12-month period, he added.
Dr. Katon, lead investigator Jürgen Unützer, M.D., (professor of psychiatry at the university), and their colleagues followed patients for an additional year after the intervention.
In other studies that included mixed-age patients, the 12-month intervention versus usual care differences tended to come together, Dr. Katon said. But in the elderly population, the usual care patients improved for about 6 months, and then their improvements reached a plateau, whereas the intervention group did gradually better during the entire 24 months.
The intervention group patients had 107 additional depression-free days, compared with the usual care patients. “That is about a one-third-of-a-year difference,” Dr. Katon said.
“We're sorry we did not take this study to a third year, since we saw equal benefit in intervention, compared with usual care patients in the second year,” he said.
Of the 107 depression-free days gained by the intervention group, 53 were in the first year, and 54 were in the second.
The John A. Hartman Foundation and the California HealthCare Foundation funded the IMPACT study.
Visit www.impact.ucla.edu
Intervention Proves Cost Effective
The IMPACT researchers calculated total outpatient costs as $11,083 in the usual care group, compared with $11,378 in the intervention group.
Thus, there is an increase of $295 in the intervention group over 24 months. In year 1, there was $383 more in ambulatory costs for intervention patients, compared with usual care—but in year 2, there was an $88 cost savings associated with the intervention.