Patient populations with multiple medical morbidities (multimorbidity) have complex health care needs and decreased ability to self-manage such needs, which often leads to poor health outcomes and increases in health care utilization costs (
1). Mental health diagnoses, including depression, have been independently shown to contribute to poor health outcomes and cost of care (
2). Collaborative care has emerged as an effective model for improving outcomes for those with chronic health conditions. It has been widely used in various settings to care for diverse patient populations (
3–
5). There is also evidence that the collaborative care model can reduce health care costs (
6–
9).
“Integrated care” and “collaborative care” are terms often used interchangeably to describe various interventions aimed at bringing together general medical and mental health services to serve the population of patients with chronic comorbid health conditions. Collaborative care is a specific form of integration based on principles of the chronic care model (
10,
11) to improve access to evidence-based mental health treatments for primary care patients. The essential elements of collaborative care include team-driven, evidence-based care that is population focused and measurement guided (
12). The team providing collaborative care generally consists of a care manager, a psychiatrist, and a primary care physician. Other support staff such as social workers and pharmacists can also be part of the team. A registry is used to monitor outcomes for selected patient populations. This helps the team to provide proactive and more intense interventions for patients who are not improving.
Close to 80 randomized controlled trials (RCTs) have now demonstrated the clinical effectiveness of collaborative care for single or multiple conditions (
4,
13). TEAMcare, a collaborative, team-based, care management program for patients with complexconditions, was part of the first RCT targeting both treatment of depression and commonly comorbid chronic health problems (
14,
15). The TEAMcare intervention demonstrated the efficacy (
14) and cost-effectiveness (
16) of a collaborative care program.
Implementation of a collaborative care model is a complex process (
17,
18). There are limited data about the implementation challenges and successes of models like TEAMcare outside of controlled studies. The U.S. Department of Veterans Affairs (VA) Mental Health Quality Enhancement Research Initiative (MH-QUERI) studied the implementation of care delivered through the TIDES (Translating Initiatives for Depression into Effective Solutions) project in the VA system. The study revealed limited time to address goals due to competing tasks and priorities, personnel and leadership turnover, limited skills and training of team members for addressing goals, and difficulty coordinating activities across teams on related goals. Despite regional differences, the VA health care system is the nation’s largest integrated health care delivery system. Challenges to implementing collaborative care delivery are likely even more significant when attempting to do so across nonintegrated systems (
19).
The COMPASS (Care of Mental, Physical and Substance-Use Syndromes) program implemented the collaborative care management model to improve the care of patients with depression and diabetes and/or cardiovascular disease across a diverse spectrum of 18 medical groups, 171 clinics, and 3,300 clinicians in eight states. The groups differed greatly in size, organizational structure, patient populations, and payment systems. The patient populations included those with commercial, Medicare, and Medicaid insurance coverage. The project’s original goals of improvement in depression, diabetes, and hypertension control were exceeded (
20,
21). The key findings from TEAMcare and COMPASS are summarized in this article.
Depression Outcomes
Depression is one of the major causes of disease burden. A majority of depressed patients receive care in a primary care setting (
22), mainly in the form of antidepressant medications (
23). Such care is often inadequate both in terms of choice of medications and dosages, as well as follow-up (
24,
25).
Unützer and colleagues conducted a trial of the IMPACT (Improving Mood Promoting Access to Collaborative Treatment) program. This trial established the effectiveness of the collaborative care model in the management of depression. Patients enrolled in the intervention arm had significantly lower depression severity than nonintervention patients at all follow-up points up to 12 months. Intervention patients also had significantly higher rates of treatment response and complete remission of depressive symptoms. They also reported improved health-related outcomes and quality of life (
26).
A 12-month single-blind, RCT of the TEAMcare program was conducted in 14 primary care clinics that were part of an integrated health care system to study the effectiveness of collaborative care for patients with both general medical and mental health problems. Patients with one or more measures of poor control of diabetes, coronary heart disease, or both were enrolled if they scored ≥10 on the Patient Health Questionnaire (PHQ-9) (
14,
15). The PHQ-9 is a self-administered diagnostic instrument for depression. It scores each of the nine
DSM-IV criteria for depression from 0, not at all, to 3, nearly every day. A PHQ-9 score ≥10 had a sensitivity of 88% and a specificity of 88% for major depression (
27).
The TEAMcare team consisted of the patient, a nurse care manager, the patient’s primary care physician, and the TEAMcare consultants, including a psychiatrist, a family medicine physician or internist, and a psychologist. Care managers screened patients for mental health problems at the initial visit. A history of past treatments, strengths, and stressors was also obtained. The care team met weekly to review new cases and patient progress toward goals. A care management tracking system was used to proactively monitor outcomes and quickly identify patients not making progress toward treatment goals. Recommendations from the psychiatric consultant were conveyed and discussed with the patient and his or her primary care physician. Care managers met with patients weekly to encourage medication adherence, behavioral activation, and self-care strategies. Contact became less frequent as patients made progress toward treatment goals (
14,
15).
The outcome measure was a multivariate primary outcome with simultaneous modeling of four separate 12-month outcomes—depression score on the Symptom Checklist−20 (SCL-20;
28), glycosylated hemoglobin level, systolic blood pressure, and low-density lipoprotein cholesterol (LDL-C) level—which allowed estimation of an overall treatment effect (
14).
TEAMcare patients showed a sixfold increase in pharmacotherapy initiations and adjustments relative to usual care patients. At 12 months, a higher proportion of patients in the intervention arm had a 50% or greater reduction in the SCL-20 depression score: 60% of patients in the intervention arm achieved depression response compared with 30% of patients receiving usual care. Patients in the intervention group were more satisfied than patients in the control group with the care that they received for general medical and psychiatric disorders (
14,
29).
Physical Health Outcomes
Patients participating in the TEAMcare trial had poorly controlled glycosylated hemoglobin A
1c (HbA
1c) levels (≥8.5%), elevated blood pressure (>140/90 mmHg), or elevated LDL-C values (>130 mg/dL). Patients with terminal illness, who were residing in long-term care facilities, with severe hearing loss, who were planning bariatric surgery, who were pregnant and/or nursing, or who showed signs of mental confusion suggesting dementia were excluded (
29).
TEAMcare patients monitored blood pressure and glucose level more frequently than patients in usual care. Patients in the intervention arm followed a healthy eating plan for more days per week and had more days per week in which they participated in 30 minutes of physical activity. Intervention participants were also more likely to meet physical activity guidelines than were usual care patients (
30).
Pharmacotherapy initiation and adjustment rates were threefold higher for insulin and nearly twofold higher for antihypertensive medications among intervention patients than among usual care patients. At the 12-month follow-up, a significantly higher percentage of patients in the intervention group showed significant clinical improvement on all three medical risk factors: glycosylated hemoglobin level, LDL-C level, and systolic blood pressure (
14,
15).
Compared with 22% of usual care patients, 37% of intervention patients met the goal for a combined primary outcome measure of an HbA
1C level <7% (or a decrease in HbA
1C of ≥.5%) and a systolic blood pressure <130 mmHg (or a decrease of ≥10 mmHg). Patients in the intervention group were more likely to have a decrease in HbA
1C level from baseline of ≥1.0% and a decrease in systolic blood pressure of ≥10 mmHg (
14,
15).
Cost-Effectiveness of Collaborative Care
There are inherent challenges in measuring the cost-effectiveness of collaborative care. Cost savings can be measured from the perspective of the payer, the health care organization, and the patient, or cost-effectiveness can be viewed from a societal perspective, measuring all benefits of the intervention, irrespective of payer and beneficiary (
31).
Also, there is no single agreed-upon estimate of the value of a depression-free day. Budget assumptions about the cost of space and personnel are variable (
32).
Despite these measurement limitations, collaborative care models have demonstrated modest cost-effectiveness. Two reviews of the economic impact of the collaborative care model have reported positive results with regard to reduced health care use, averted productivity loss, and cost-effectiveness (
31,
32).
In the TEAMcare study, depression and general health measures for collaborative care were significantly better at 12 months. Depression improvement alone is associated with significant improvement in quality of life of patients with chronic physical illness. Katon and colleagues (
16) estimated that during the two-year study, intervention was associated with reducing total outpatient costs by $594 per patient. The incremental cost-effectiveness ratio found a mean cost savings of $1,773 per quality-of-life year (QALY). The cost-effectiveness acceptability curve analysis found a 99.7% probability that this intervention would cost less than $20,000 per QALY, which is the threshold for recommending rapid dissemination of an intervention to health care systems (
16).
Implementation of the Collaborative Care Model
Despite substantial and growing evidence for the effectiveness and cost-effectiveness of the collaborative care model, its implementation outside of clinical trials is lagging (
33). In 2012, the Center for Medicare and Medicaid Innovation (CMMI) announced the Health Care Innovation Awards to implement initiatives across the nation to improve patients’ health and provide them with better care and lower costs. The COMPASS initiative was one of the awardees in this CMMI program. The implementation of the COMPASS initiative was overseen by the Institute for Clinical Systems Improvement in Minnesota (
34).
The COMPASS initiative spread an evidence-based collaborative care model among 18 medical groups and 172 clinics in eight states. The sites included clinics in rural, suburban, and urban settings serving patients of various cultures and economic statuses. The medical groups included both multispecialty and primary care practices of a variety of sizes (
20).
The COMPASS trial recruited patients with depression and comorbid poorly controlled diabetes or cardiovascular disease in primary care settings. Patients with PHQ-9 scores ≥10 and with either poorly controlled diabetes (HbA1c ≥8%) or cardiovascular disease (LDL-C ≥100 mg/dL or blood pressure ≥140/90 mmHg) were selected. Treatment targets were a PHQ-9 score <10 or a 5-point decrease in PHQ-9 score, an HbA1c level <8.0%, or blood pressure <140/90 mmHg. All outcomes were patients’ last observed outcomes during the project.
The model of care used in the COMPASS initiative was informed by that used in the TEAMcare (
14,
15) program but was not identical. Site-specific resources and existing unique needs and limitations necessitated differences between the two approaches. In the TEAMcare model, care managers were nurses trained to care for diabetic patients with depression, whereas in the COMPASS initiative care nurses were primary care nurses or sometimes nurses with mental health backgrounds. Condition-specific cross-training had to be provided to nurse care managers. In addition, participating sites in the COMPASS trial were allowed to conform the core elements of treatment to existing treatment guidelines for managing conditions (
20).
The care team, consisting of a care manager with direct patient contact, a consulting primary care physician, and a psychiatrist, met weekly to conduct systematic case reviews utilizing a registry of enrolled patients and medical records. Initial care plans were established, and treatment intensification was recommended for poor responders or nonresponders. A care coordinator provided motivational interviewing, implemented behavioral activation, and helped the patient set personal health goals and develop strategies for self-monitoring, treatment adherence, and problem-solving skills. Interventions and contact frequency changed depending on a patient’s progress toward goals.
At the time of enrollment, self-reported PHQ-9 scores showed that 48% of patients had moderate depression, 28% had moderate to severe depression, and 25% had severe depression. After treatment, 24% of patients experienced depression remission (PHQ-9 score <5), and 16% experienced depression response (at least a 50% decrease in PHQ-9 score) (
21).
Of those with poorly controlled diabetes, almost half had very elevated HbA
1c levels (≥9.5%). Of those with HbA
1c ≥8%, 23% went on to achieve HbA
1c <8.0%. Stage 1 hypertension (systolic blood pressure=140–159 mmHg or diastolic blood pressure=90–99 mmHg) was present in 72% of patients, whereas 28% had stage 2 hypertension (systolic blood pressure >160 mmHg or diastolic blood pressure ≥100 mmHg). After treatment, 58% of patients achieved hypertension control. Longer duration of participation (>3 months) was associated with greater likelihood of diabetes and hypertension control (
21).
There was variability in implementation and outcomes across sites. This is not surprising given the diversity of the participating organizations. Backgrounds of care managers varied and included nursing, physician assistant, social work, and medical assistant degrees. Depending on location, care managers either had contact with patients in person and by phone or by phone only. Types of patient registries also varied.
Patient outcomes varied considerably between medical groups. Depression remission rates ranged from 5% to 41%, depression response rates ranged from 6% to 26%, and HbA
1c <8% was achieved with 7% to 33% of participants. Hypertension outcomes varied from 27% to 76%. No clear associations between participating organization characteristics and outcomes were evident. Infrequent systematic case review was associated with poor outcomes on all parameters for one group, and use of custom registries was associated with poor depression response and remission rates for two groups (
21). While interpreting these results one needs to be mindful that COMPASS was implemented as a demonstration project rather than as an RCT (
21).
Conclusions
The success of the collaborative care model of chronic disease management is now well established. More than 80 RCTs have demonstrated its success in treating depression in primary care. The TEAMcare initiative further established the model’s success in managing depression along with comorbid chronic general medical conditions. Collaborative care has also demonstrated improved patient and provider satisfaction. The IMPACT and TEAMcare models have also reported cost savings in care of depression and comorbid health conditions, spread over several years.
The COMPASS project has established that wide-scale implementation of the collaborative care model is possible and effective. Diversity in organizational structures, resource availability, and existing workflows required flexibility in implementation at various sites. The impact of site-specific variations on the implementation process and outcomes needs further study. Despite these variations, however, the COMPASS project showed robust benefits of the collaborative care model in diverse health care systems.
Implementation of the collaborative care model has lagged in part because various services that constitute care coordination have not been reimbursed (
35). Recognizing the robust effectiveness data and the successful implementation and cost savings demonstrated in diverse organizations, the Centers for Medicare and Medicaid Services established new coding and payment mechanisms for behavioral health integration. Three of these codes are specific to the psychiatric collaborative care model (CoCM), and one code addresses other behavioral health integration models (
36,
37).