Translating Research Into Practice
Depression, one of the most prevalent and debilitating mental health conditions, affects 17.6 million Americans of all ages each year; costs for treatment are estimated at $12 billion. Untreated depression may cost as much as $24 billion in lost productivity as well. With symptoms ranging from mild but chronically depressed moods to more severe episodes, people diagnosed with this disorder share a common set of difficulties that affect their functioning and quality of life. Many more people live with some depressive symptoms that also reduce their ability to lead full and productive lives.
Overview / Improving Diagnosis / Improving Treatment / Challenges for Future Treatment
Research on diagnosing and treating depression, including that sponsored by the Agency for Healthcare Research and Quality (AHRQ, formerly known as the Agency for Health Care Policy and Research), can help patients and their families, health policymakers, and business leaders understand that depression is a distinct and treatable condition and that removing barriers to care is critical to improving workplace productivity and quality of life. In addition, health care research now faces a new challenge: how to develop and implement effective strategies that can bridge the gap between what we know and what we do to improve health care for people with depression.
Patients with a history of heart attacks have almost twice as many depressive spells annually as depressed patients without a previous heart attack. Depressed elderly patients had $200 more in diagnostic test costs and 1.5 more ambulatory care visits over the course of a year than similar patients without depression.
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AHRQ-sponsored research has shown that people diagnosed with depression experience long-lasting problems in daily functioning and sense of well-being, comparable to or worse than patients with chronic illnesses such as diabetes or congestive heart failure. According to another AHRQ study, depressed patients continue to suffer symptoms and spells even at 2 years of followup.
In a major 1993 review of the clinical literature on depression, an expert panel convened by AHRQ concluded that, despite the substantial effects depression has on health and functioning, the disease is both underdiagnosed and undertreated. According to the panel, primary care physicians are the providers most likely to see patients when they first become depressed; yet only one-third to one-half of people with depression are diagnosed as such by their primary care physicians. The likelihood of detecting depression increases 24 percent with each additional year of a patient's education, and depression is almost twice as likely to be recognized in women as in men.
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The AHRQ-sponsored expert panel concluded that depression, once identified, can almost always be treated successfully. Yet appropriate treatment continues to be a pressing issue.
As part of its emphasis on enhancing the science base for health decisionmaking, AHRQ released Treatment of Depression—Newer Pharmacotherapies: Summary in March 1999. The full evidence report, prepared by AHRQ's Evidence-based Practice Center based at the University of Texas Health Science Center at San Antonio, is available from the AHRQ Clearinghouse.
Efficacy of New Drugs
A recent AHRQ-funded review of 32 pharmaceutical and herbal treatments for depression found evidence which suggested that drugs in the older class of pharmaceuticals (tricyclic antidepressants) are generally as efficacious as newer drugs (selective serotonin reuptake inhibitors, or SSRIs). The study also found that patients discontinue their use of these drugs at similar rates, 4 versus 5 percent, although the two categories of drugs differ in the kinds of side effects patients are most likely to experience.
Depression often coexists with other long-term health problems, presenting additional complexities. About 60 percent of depressed outpatients have at least one other chronic medical condition as well, such as a heart problem, high blood pressure, or diabetes. AHRQ-funded research has shown that patients with a history of heart attacks have 1.8 times more depressive spells in a year and more persistent symptoms than depressed patients without a history of heart attacks.
The challenge of treating depression as one of multiple chronic conditions is especially an issue in older persons. AHRQ research comparing elderly patients with and without depression in a primary care clinic found that the depressed patients had:
- Nearly $200 more in annual diagnostic test costs.
- Almost 1.5 more ambulatory care visits per year.
- Over 12 percent more annual visits to the emergency department.
- Five percent more hospitalizations each year.
To reduce the cost of care and improve outcomes for older persons with depression, coexisting psychiatric and medical illnesses must be targeted for treatment.
Organization of Care
The organization of care can affect care delivery for depression. One AHRQ-sponsored study showed that shifting patients away from mental health specialists to general medical providers (as is the practice in some managed care arrangements) may lead to fewer improvements in patient functioning but costs two to three times less. Other AHRQ-funded research on the effects of changes in health care payment and delivery found that after switching to a prepaid plan, the health status of outpatients with depression did not appear to suffer although they were 12 percent less likely to use antidepressants and made 35 to 40 percent fewer visits to their mental health care providers.
Use of Guidelines
Even where there is substantial agreement about how treatment for depression can be improved, changes to everyday practice have been slow. Past efforts by managed care organizations to improve compliance with guidelines for improving diagnosis and treatment of depression have met with only modest success.
Two AHRQ studies investigating academic detailing and continuous quality improvement interventions in managed care organizations concluded that these approaches were only mildly effective in improving clinicians' adherence to the recommended guidelines for care. However, promising early results from a current study evaluating ways to increase use of antidepressants and psychotherapy in managed primary care practice suggest that depressed patients in the intervention groups were more likely to receive these interventions and exhibit better outcomes.
The National Guideline Clearinghouse™ (NGC) sponsored by AHRQ in partnership with the American Medical Association and the American Association of Health Plans, allows physicians and other Internet users to assess and compare guidelines online at http://www.guideline.gov. The NGC is being used by Georgetown University Medical Center's Mood Disorder Program in the development of clinical practice guidelines on depression for primary care physicians in managed care settings.
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Challenges for Future Research
Gaps between what we know and what we need to know in the diagnosis and treatment of depression still exist, especially in how depression interacts with chronic physical illnesses, how to measure the quality of depression care, and how to provide care that results in good outcomes at an acceptable cost for all age groups. Developing more effective strategies to translate knowledge into improved care is an important area for future research.
Topics of current AHRQ studies addressing some of the remaining research questions include:
- Computerized decision-support in primary care. This study is investigating outcomes and costs associated with a computerized system that helps primary care physicians implement treatment recommendations for their depressed patients.
- Influences on referrals to specialty care. Incentives to contain costs may affect the willingness of primary care physicians to refer depressed patients to specialists. This study is examining referral patterns and comparing the health outcomes of referred and nonreferred patients.
- Therapies for adolescents with depression. These investigators are assessing whether specific interventions can improve the outcomes of care for depressed adolescents and young adults, including patient and provider education as well as use of antidepressants and behavioral therapy. This study represents a significant step forward in addressing a very difficult problem for many affected families.
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AHRQ Publication No. 00-P020
Replaces AHCPR Publication No. 99-P023
Current as of January 2000
Improving Quality of Care for People With Depression. Translating Research Into Practice. Fact Sheet. AHRQ Publication No. 00-P020, January 2000. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/research/deprqoc.htm