Diabetes Prevention and Control: Disease and Case Management Interventions

Research Gaps

What are Research Gaps?

Prior to and during the literature review and data analysis, the review team and the Community Preventive Services Task Force attempt to address the key questions of what interventions work, for whom, under what conditions, and at what cost. Lack of sufficient information often leaves one or more of these questions unanswered. The Community Guide refers to these as "research gaps." Research gaps can be pulled together in the form of a basic set of questions to inform a research agenda for those in the field.

Identified Research Gaps

Even though disease and case management were found effective in the managed care setting for improving glycemic control and provider monitoring of certain important outcomes, several important research gaps were identified in this review. One of the most pressing needs is to better define effective interventions. Disease management has multiple component interventions. To make optimal use of resources, however, only the interventions that contribute most to positive outcomes should be implemented, and these need to be defined. Case management interventions are also usually delivered with other interventions, and the effectiveness of these also needs to be defined. Are case management interventions delivered with disease management more effective than case management delivered as a single intervention? Are there specific additional interventions that augment the effectiveness of disease and case management, such as DSME? Additional research questions relating to case management include identifying the optimal intensity (frequency and duration) of patient contact and determining whether professionals other than nurses (e.g., social workers or pharmacists) could function as case managers.

How best to integrate disease and case management interventions into existing healthcare systems also needs to be addressed. What are the strengths and limitations of delivering these interventions as part of primary care or specialty care, or might they best be delivered by contracted organizations and provider networks that are separate from the patient's healthcare delivery system (i.e., the carve-out model)?

Although the existing effectiveness literature examines many important outcomes, research is needed to determine the effect of disease and case management on long-term health and quality of life outcomes, including cardiovascular disease events, renal failure, visual impairment, amputations, and mortality. Further work is also needed to determine the effect of case management on blood pressure, weight, lipid concentrations, and provider screening rates for retinopathy, peripheral neuropathy, and microalbuminuria. In addition, provider and patient satisfaction with these interventions need much more attention from researchers.

As discussed above, the applicability of these data are somewhat limited, leaving numerous important questions unanswered. For example, are disease and case management effective in settings other than HMOs and community clinics, such as academic clinics and independent private practices? Do these interventions work better in some types of delivery systems than others? Are they effective for adolescents with diabetes? How do the cultural, educational, and socioeconomic characteristics of a population affect outcomes? What are the key barriers that providers perceive for disease and case management? How would it be best to obviate them? Do patients perceive any barriers to these interventions?

Numerous deficiencies in the methodologies of these studies were identified. Often there was inadequate descriptive information; studies need to include adequate demographic information (at a minimum, age, gender, race or ethnicity, and type of diabetes), a description of the delivery system infrastructure (automated information systems, prior use of guidelines, resource support, management [medical and non-medical] commitment and support), and details of the intervention (components, frequency and duration of patient contact, who delivered the intervention, whether and which clinical practice guidelines were used, and degree and type of interface with primary care). In addition, more studies are needed with a concurrent comparison group to control for secular trends in healthcare delivery and patient practices. Finally, studies are needed in which a broad range of providers is recruited.

Evidence Review

Norris SL, Nichols PJ, Caspersen CJ, et al. The effectiveness of disease and case management for people with diabetes. Am J Prev Med 2002;22(4S):15-38.