3.3.1. System Function

System function refers to the services provided. As described in Section 2.2.1, the function of providing behavioral health within primary care in accordance with the CoCM was decomposed into several processes organized into three functional levels. Following the clinical diagnostic framework, a **high-level functional model** of Integrated Behavioral Health (BH) is presented in Figure 4.

It is composed of four functions: a function describing the engagemen<sup>t</sup> of the patient with the healthcare delivery system and the three functions from the clinical diagnostic framework. Specifically, *Function 1, Engage* patient describes the collective functions by which patients engage, interact, and enter the healthcare delivery system. This includes phone calls to make appointments, administrative check-in (e.g., check in at the reception desk) and clinical check-in (e.g., room patient, take vitals) processes that generally occur before a patient sees the primary care provider. *Function 2, Identify/Measure* behavioral health needs and severity describes the classic first step process of identifying and measuring a patient need and if required severity. *Function 3, Decide* on the care plan follows the identification of a behavioral health need. Deciding on a care plan incorporates understanding the patient's needs taking into consideration their wishes and circumstances and determining how to fulfill them. This includes deciding how to proceed within the healthcare system. This may include deciding to engage an integrated behavioral health clinician to provide therapy or measurement followup. It may also include deciding that more significant behavioral health services are needed beyond what may be provided within the integrated behavioral health service. In that case, direct referral to external services may occur, or a more active referral may be initiated. *Function 4, Deliver* service/treatment describes the delivery of treatments or services based on the developed care plan.

**Figure 4.** System Function: High-level functional model for Integrated Behavioral Health.

The **1st level functional model** of Integrated Behavioral Health, shown in Figure 4, is represented using SysML in Figure 5. These functional diagrams are called activity diagrams in SysML. This 1st level represents the primary care clinic-level system model without explicitly representing any specific integrated behavioral health functions. It shows patient contact or physical arrival (i.e., virtual or physical presence at the clinic) as inputs to this level. It also shows patients as outputs from this level when they are referred or supported into long-term external services. The figure also explicitly shows a significant problem in behavioral health, one of leakiness of patients coming from a patient's decision to not continue, follow through, or engage in next care steps, or their inability to remain engaged.

The **2nd level functional model** begins to show the details of the model classically recognized as collaborative care, as shown in Figure 6, and specifically in the Deliver Care dotted box. The 1st level identify/measure function described as "identify patients with BH needs" is functionally performed in the 2nd level by "determining and administering screening function". The CoCM health community typically names this step "systematic screening". The 2nd level functional model also specifically shows the decision function "determine needed BH services" as the gate to the options for BH services of the high-level deliver care function. It also makes it clear that there are four different types of internal services that integrated behavioral health services can provide in primary care. The details of each of these four services are described in the 3rd level functional model.

The **3rd level functional model** is the level where specific processes are defined and can be specifically allocated to resources. Interestingly, implementation teams allocate who will perform each process at the 2nd not 3rd level. This highlights that implementers have some form of a working visual model of the sequence of processes shown in the 2nd level in Figure 6, although this visual is not represented in any of the CoCM documentation figures. Implementers allocate at the 2nd level since most of the processes represented by the yellow rectangles can be assigned to a single provider; in this case, a primary care clinician resource or behavioral health clinician resource.

Many of the functions described as key aspects to the success of integrating behavioral health into primary care are processes that require the collaboration of two or more resources. For example, the decide function (Level 1) of "determine needed BH services" (Level 2) includes a key supporting task called "engage in curbside consult" (Level 3.3, shown in Figure 7), which occurs between a primary care clinician resource and a behavioral health clinician resource, shown with a red background. This is a key task that helps with quicker identification and faster directed care towards the appropriate services needed for the patient. This task also fulfills the function of educating and training primary care clinician resources to identify, determine, and provide behavioral health care more robustly.

A second example of this can be seen under the deliver care function (Level 1) of "provide medication management" (Level 2), which includes two key supporting tasks called "engage in curbside consult" and "warm handoff—introduce patient to behavioral health clinician" (Level 3.4, shown in Figure 8) and also shown with a red background.

Not specifically identifying the need for the additional clinical resource does not provide future implements with the details to recognize what functions require these multiple resource collaborations and how to design both of their workflows to ensure that they can both engage and perform these collaborative functions efficiently and consistently.

The development of system function using the activity diagrams allows for several noteworthy contributions. First, the clinical team providing services to patients include several types of clinicians: primary care clinicians, psychiatrists, and behavioral health clinicians. While, in theory, all clinicians may have a high-level understanding of the roles of their team members, the system model visually and cognitively clarifies the processes, flows, problems, concerns, and issues of how an individual's workflow can potentially impact other team members' workflow. This understanding was critical for implementation processes to minimize typical and current problems and dissatisfactions by colleagues and patients. Furthermore, it is important to note that the professional environment for healthcare human resources is very hierarchical, with medical doctor (MD) clinicians at the top and non-MD clinicians socially relegated to a lower clinician status. This modeling approach brought justification and voice to team members typically unheard or marginalized, whose information was invaluable in helping develop and improve patient care experience. This section described the functions performed in the CoCM detailing the processes and interconnections at three levels. We now turn to describing a system form that embodies and performs the processes described.

**Figure 7.** System Function: Level 3.3 Activity Diagram: Determine needed behavioral health (BH) services. The function highlighted in red is performed by two healthcare delivery system resources: a behavioral health clinician (BHC) and a primary care physician.

**Figure 8.** System Function: Level 3.4 Activity Diagram: Provide medication management. The functions highlighted in red are performed by two healthcare delivery system resources: a behavioral health clinician (BHC) and a primary care physician.

## 3.3.2. System Form

System form in healthcare includes the human and technical resources (i.e., the people (clinical and administrative) and the tools and rooms (the electronic medical record—EMR, examination materials, etc.). The human and technical resources in the CoCM are represented using a block definition diagram in SySML Figure 9. Resources are described at the level describing provider type (e.g., nurse, receptionist, primary care provider, behavioral health clinician). In the instance where the actual resource is identified, a specific human resource name would be included. For privacy, no specific names are included in the resource diagram. Resources are also grouped based on the system boundary they belong to (i.e., Integrated Behavioral Health Service, Department of Internal Medicine, Department of Psychiatry, or External System). The description of primary care and collaborative care personnel from different departments is highlighted in the background rather than described as part of the specification of System Form. This is because these classes of personnel are typically part of different departments, but this may not be the case in every implementation site. An allocation from the external system showing counselors allocated to collaborative care represents the instances when more personnel or specific types of personnel, such as counselors, are brought in to support collaborative care. The External System may include some, none, or possibly more services than have been shown. The classes of community behavioral health services included are ones typically needed when behavioral health needs are identified. The typical types of external resources are represented in the model, however, as one may speculate, the specific types and numbers of external services vary based on the implementation site.

## 3.3.3. System Concept

System concept refers to the allocation of function to form, or, in other words, what (function) is performed by who (form). This is visualized in the allocation matrix in Figure 10. The allocation makes clear what processes are performed by which resource or groups of resources. In many instances, both technical and human resources are allocated to performing a specific process. Such a mapping allows implementing organizations to decide, based on their own resource availabilities, how to perform the needed tasks and therefore create their own system concept. For example, the function of "referring to long-term external behavior health services", typically performed by a behavioral health clinician can instead be performed by a social worker who is not licensed to provide behavioral health treatment, thus freeing up behavioral health clinician time to perform other functions that require behavioral health expertise.


**Figure 10.** System Concept: The allocation of the 3rd level system functions to system form for Integrated Behavioral Health.
