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Hickam DH, Weiss JW, Guise JM, et al. Outpatient Case Management for Adults With Medical Illness and Complex Care Needs [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2013 Jan. (Comparative Effectiveness Reviews, No. 99.)

  • This publication is provided for historical reference only and the information may be out of date.

This publication is provided for historical reference only and the information may be out of date.

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Outpatient Case Management for Adults With Medical Illness and Complex Care Needs [Internet].

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Chronic diseases are the leading cause of illness, disability, and death in the United States.1 Nearly half of all adults in the United States have at least one chronic disease, and 43 percent of adults covered by both Parts A and B of Medicare have three or more chronic diseases.2 Providing medical care for chronic illness is often complex. Patients require multiple resources, treatments, and providers that, in many health care settings, are not integrated into a coherent system of care. This fragmentation puts patients with serious or multiple chronic illnesses at risk of experiencing inadequate quality of care and makes their health care expenditures substantially higher than for those who have minor or no chronic conditions.3

A strategy to improve the coordination and efficiency of care for chronic conditions is to add supplemental services and personnel to improve care coordination and implement care plans.4-6 Case management (CM) is one such supplemental service, in which a single person, usually a nurse or social worker, takes responsibility for coordinating and implementing a patient's care plan, either alone or in conjunction with a team of health professionals. Early models of CM were developed as part of the community health nursing movement of the early twentieth century. They were designed largely to promote patient self-help and coordinate community resources.7 A central feature of these models was that the nurse case manager had roles in both coordinating services and providing clinical care directly.8 In the 1970s CM was widely used to meet the needs of patients with chronic psychiatric diseases.9-11 In the AIDS epidemic of the 1980s, CM was adopted to coordinate treatment programs for HIV-infected individuals. At about the same time, a model of CM for the frail elderly began to be disseminated.12 In the 1990's training programs for case managers were greatly expanded, and case management certification programs were established.

The evolution of CM models in health care, and their expanding use in chronic illness management, has led to the term “case management” being used to describe a wide variety of interventions. As a result, there is no consensus as to what constitutes CM. Moreover, the term “case management” is often used interchangeably with other forms of chronic illness management interventions, such as “disease management,” and “self-management support.” The health professionals administering those programs, usually nurses, are often referred to as case managers. The conflation of these different terms—and their unsystematic use in describing nurse-led, chronic illness management interventions—makes it challenging to examine the contribution of CM as a distinct entity. For example, McDonald et al. reviewed 75 systematic reviews of studies evaluating the effectiveness of care coordination strategies for patients with chronic illness.6 Many of these strategies were nurse-led interventions for patients with diabetes, congestive heart failure (CHF), and other chronic conditions, and 21 of the systematic reviews reported evaluating CM as an explicit objective. Most of these systematic reviews included studies of interventions that carried the label “case management” but did not typically define CM or distinguish it from other nurse-led interventions. Most of these reviews also did not isolate the effects of CM from other clinical interventions.6

Distinguishing Case Management From Other Interventions

We sought to add to the existing body of evidence on chronic illness management interventions by evaluating the distinct contribution of CM as a specific strategy. CM tends to be more intensive in time and resources than other chronic illness management interventions. To distinguish CM from other interventions, we drew upon definitions of CM in the literature and those used by professional organizations of case managers (see Appendix A). We also consulted with members of our Technical Expert Panel (TEP) who are experts in the field of CM. Those definitions and expert opinions indicated that a defining feature of CM is the central role of the case manager as comprehensive coordinator of a patient's care. The coordinating functions performed by a case manager include helping patients navigate health care systems, connecting them with community resources, orchestrating multiple facets of health care delivery, and assisting with administrative and logistical tasks. These coordinating functions are distinct from clinical functions, including disease-oriented assessment and monitoring, medication adjustment, health education, and self-care instructions. Such clinical functions are often the defining aspects of other chronic illness management interventions that are staffed by nurses.13 In the context of chronic illness care, they are central to the role of a case manager as well, but a case manager also performs coordinating functions. The role of case managers in chronic illness care, and their distinction from other professionals involved in chronic illness management support, can be illustrated using the Chronic Care Model (see Figure 1).

This figure of the chronic care model developed by the McColl Institute depicts an overarching circle with components of community and health systems, along with resources and policies; self-management support; organization of health care; delivery system design; decision support; and clinical information systems. These components are shown influencing productive interactions between the informed, activated patient and the prepared, proactice proactive team, which leads to improved outcomes.

Figure 1

Chronic care model. Developed by The MacColl Institute ® ACP-ASIM Journals and Books

Many chronic illness management interventions include professionals (usually nurses) who are members of a clinical practice team or perform discrete clinical functions (e.g., clinical monitoring and education) on behalf of the practice team. A case manager also performs these functions, but a central role of the case manager is to coordinate and integrate different types of services, including community resources, health systems, and the practice team, on behalf of the patient. CM is often utilized when such coordination and integration are inherently challenging and difficult for patients to accomplish on their own. CM usually involves high-intensity engagement with such patients, and case managers often adopt a supervisory role in comprehensively attending to patients' complex needs.14 Conceptually, a case manager can be seen as an agent of the patient, taking a “whole person” (rather than solely clinical or disease-focused) approach to care, and serving as a bridge between the patient, the practice team, the health system, and community resources. Features of CM programs, based on the interventions described in the studies included in this review, are summarized in Table 1.

Table 1. Features of case management programs.

Table 1

Features of case management programs.

In defining the functions of CM, two general models have been described. The gatekeeper (or interrogative) model focuses on controlling access to and ensuring efficient use of clinical services, while the patient advocacy (or brokering) model focuses on coordinating services and improving the quality of care. In current practice, a combined model that utilizes both approaches is most commonly used.15-17 However, not all chronic illness management interventions that include clinical and coordinating activities are CM. A defining aspect of CM is that it involves a single person or small group of people (i.e., case managers) who are responsible for those activities. Other chronic illness management interventions—including “multidisciplinary teams” and “organized specialty clinics”6—may include clinical and coordinating activities as part of their overall approach to care, but such team-based interventions are distinct from CM. Another feature of CM is the level and duration of engagement with patients. Some chronic illness management interventions, particularly those designed to smooth transitions of care, include clinical and coordinating functions but are limited to one or two encounters with the patient. CM involves longitudinal engagement with patients, allowing for the development of a case manager-patient relationship.

Finally, CM is a supplemental intervention that occurs in addition to (and often in conjunction with) “usual” clinical care. A primary care or specialist practitioner caring for a patient may perform both clinical and coordinating activities, may be the principal person responsible for those functions, and may have a longitudinal relationship with the patient. But these “usual care” practitioners (e.g., primary care practitioners) are not considered case managers.

Variability of Case Management Implementation

Even when CM is defined explicitly—as a longitudinal intervention in which a single person, working alone or in conjunction with a team, coordinates services and augments clinical care for patients with chronic illness—there is wide variation in its implementation. Individual CM programs usually are customized for the clinical problems of the population being served. Thus, a CM program for homeless people with AIDS has a much different mix of activities than a program serving patients with dementia and their caregivers, or one designed to improve the quality of diabetes care. Some CM interventions include primarily coordinating functions, while others focus mainly on clinical activities. Some target patients with characteristics—limited social support or physical or mental disability—that make them particularly vulnerable to lack of care coordination, while others serve unselected populations with a given chronic illness. Some interventions are intensive, with multiple face-to-face interactions and home visits, while others entail only infrequent telephone calls. In some, case managers operate independently, while in others, they work closely with a patient's usual care provider or with a multidisciplinary team of health professionals. This variability of CM interventions makes it challenging to evaluate the effectiveness of CM as a discrete entity. It is therefore of potentially greater interest to evaluate the impact of specific components within CM intervention “packages.” However, in many studies, the way in which CM is implemented is poorly described, making it difficult to study the individual components of CM interventions.

Scope and Key Questions

The Agency for Healthcare Research and Quality (AHRQ) commissioned this Comparative Effectiveness Review (CER) to examine the evidence for the effectiveness of CM programs for chronic illness patients with complex care needs. To define the scope of the review, we used the framework described above to define CM interventions. Specifically, we considered interventions in which case managers had a substantive role in performing both clinical and coordinating functions. Although some interventions may include coordinating functions without explicitly describing them, we only included interventions in this review for which those functions were central enough to the manager's role to be described as part of the intervention. Because the balance of clinical and coordinating activities varies widely across CM interventions, our review included a diverse array of interventions in which case manager roles spanned a continuum, from predominantly clinical to predominantly coordinating in nature.18 We used the description of the intervention and its components, rather than its label, to make decisions about which interventions had the defining characteristics of CM as described above. Thus, we did not include all interventions that were labeled in the literature as CM, and we sometimes included interventions carrying other labels (including care management and disease management).

As noted, the situations in which CM has been used are numerous and diverse. In recognition of the substantial heterogeneity of purposes, approaches, and populations included within the broad category of CM, we limited the scope of this review in a number of ways. We aimed to define and identify a subset of CM models representing a sizable category of CM that is common and meaningful for patients and their caregivers. We also aimed to circumscribe the scope of included CM models to ensure that a review of this type would be adequately focused and practical. Such an approach allows for a more complete understanding of the evidence regarding the included category of CM. We limited the scope of this review to CM interventions for medical, as opposed to psychiatric, illness. CM is often used to improve the management of psychiatric illnesses such as depression or schizophrenia, as well as substance use disorders. CM in those contexts, however, is substantively different in its nature and objectives from CM for chronic medical illness. Although we did not include studies in which the goal of CM was primarily to improve psychiatric care, we did include studies in which CM was used to improve chronic medical illness care among patients who also had psychiatric illness. Similarly, we included models of care management that integrated care for both medical and psychiatric illness. Additionally, we restricted the review to CM that was characterized by an ongoing and sustained relationship between the case manager and patient. Hence, despite promising evidence for certain models of short-term, intensive CM or models that focus on transitional care,19-21 we did not include such models in this review. We also limited the scope of this review to outpatient settings. This report summarizes the existing evidence addressing the following Key Questions in the outpatient setting:

Key Question 1:

In adults with chronic medical illness and complex care needs, is case management effective in improving:

  1. Patient-centered outcomes, including mortality, quality of life, disease-specific health outcomes, avoidance of nursing home placement, and patient satisfaction with care?
  2. Quality of care, as indicated by disease-specific process measures, receipt of recommended health care services, adherence to therapy, missed appointments, patient self-management, and changes in health behavior?
  3. Resource utilization, including overall financial cost, hospitalization rates, days in the hospital, emergency department use, and number of clinic visits (including primary care and other provider visits)?

Key Question 2:

Does the effectiveness of case management differ according to patient characteristics, including but not limited to: particular medical conditions, number or type of comorbidities, patient age and socioeconomic status, social support, and/or level of formally assessed health risk?

Key Question 3:

Does the effectiveness of case management differ according to intervention characteristics, including but not limited to: practice or health care system setting; case manager experience, training, or skills; case management intensity, duration, and integration with other care providers; and the specific functions performed by case managers?

Organization of the Report

Following this introduction are chapters on methods; results; summary and discussion, including limitations of the review; conclusions; and future research. The reference list appears at the end of the report, along with a table of abbreviations used throughout the report. The results chapter is divided into several major sections: search results, with a study flow diagram; overall effectiveness of case management and results for each of the Key Questions; and effectiveness of case management in defined patient populations. The defined patient populations are—

  • Older adults with one or more chronic diseases
  • Frail elderly
  • Patients with dementia
  • Patients with congestive heart failure
  • Patients with diabetes mellitus
  • Patients with cancer
  • Patients with serious chronic infections
  • Patients with other medical problems

Each section on a defined patient populations presents—

  • An overall description of studies
  • Key points related to the evidence about patient-centered outcomes (quality of care, health care utilization, patient characteristics, and intervention characteristics)
  • Analysis of effectiveness of case management by outcome (patient-centered outcomes, quality of care outcomes, and resource utilization)
  • Analysis of effectiveness of case management by patient characteristics
  • Analysis of effectiveness of case management by intervention characteristics


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