This is the current release of the guideline.

This guideline updates a previous version: American Diabetes Association (ADA). Standards of medical care in diabetes. IV. Prevention/delay of type 2 diabetes. Diabetes Care 2011 Jan;34(Suppl 1):S16.

Prediabetes, i.e.,

• Impaired fasting glucose (IFG)
• Impaired glucose tolerance (IGT)
• Elevated glycosylated hemoglobin (A1C)

Individuals with risk factors for type 2 diabetes mellitus

For the current revision of this position statement, committee members systematically searched Medline for human studies related to each subsection and published since 1 January 2010.

Not stated

American Diabetes Association's Evidence Grading System for Clinical Practice Recommendations

A

Clear evidence from well-conducted, generalizable randomized controlled trials (RCTs) that are adequately powered, including:

• Evidence from a well-conducted multicenter trial
• Evidence from a meta-analysis that incorporated quality ratings in the analysis

Compelling nonexperimental evidence (i.e., "all or none" rule developed by the Centre for Evidence-Based Medicine at Oxford)

Supportive evidence from well-conducted RCTs that are adequately powered, including:

• Evidence from a well-conducted trial at one or more institutions
• Evidence from a meta-analysis that incorporated quality ratings in the analysis

B

Supportive evidence from well-conducted cohort studies, including:

• Evidence from a well-conducted prospective cohort study or registry
• Evidence from a well-conducted meta-analysis of cohort studies

Supportive evidence from a well-conducted case-control study

C

Supportive evidence from poorly controlled or uncontrolled studies, including:

• Evidence from RCTs with one or more major or three or more minor methodological flaws that could invalidate the results
• Evidence from observational studies with high potential for bias (such as case series with comparison to historical controls)
• Evidence from case series or case reports

Conflicting evidence with the weight of evidence supporting the recommendation

E

Expert consensus or clinical experience

A grading system (see the "Rating Scheme for the Strength of the Evidence" field), developed by the American Diabetes Association (ADA) and modeled after existing methods, was utilized to clarify and codify the evidence that forms the basis for the recommendations.

Recommendations (bulleted at the beginning of each subsection and also listed in the "Executive Summary: Standards of Medical Care in Diabetes 2012" [see the "Availability of Companion Documents" field]) were revised based on new evidence or, in some cases, to clarify the prior recommendation or match the strength of the wording to the strength of the evidence. A table linking the changes in recommendations to new evidence can be reviewed at http://professional.diabetes.org/CPR_Search.aspx .

Feedback from the larger clinical community was valuable for the 2012 revision of the standards.

Recommendations have been assigned ratings of A, B, or C, depending on the quality of evidence (see the "Rating Scheme for the Strength of the Evidence" field). Expert opinion (E) is a separate category for recommendations in which there is as yet no evidence from clinical trials, in which clinical trials may be impractical, or in which there is conflicting evidence. Recommendations with an "A" rating are based on large, well-designed clinical trials or well-done meta-analyses. Generally, these recommendations have the best chance of improving outcomes when applied to the population to which they are appropriate. Recommendations with lower levels of evidence may be equally important but are not as well supported.

The standards of care were reviewed and approved by the Executive Committee of the American Diabetes Association's (ADA's) Board of Directors, which includes health care professionals, scientists, and lay people.

The evidence grading system for clinical practice recommendations (A–C, E) is defined at the end of the "Major Recommendations" field.

Prevention/Delay of Type 2 Diabetes

• Patients with impaired glucose tolerance (IGT) (A), impaired fasting glucose (IFG) (E), or a glycosylated hemoglobin (A1C) of 5.7% to 6.4% (E) should be referred to an effective ongoing support program targeting weight loss of 7% of body weight and increasing physical activity to at least 150 min/week of moderate activity such as walking.
• Follow-up counseling appears to be important for success. (B)
• Based on the cost-effectiveness of diabetes prevention, such programs should be covered by third-party payers. (E)
• Metformin therapy for prevention of type 2 diabetes may be considered in those with IGT (A), IFG (E), or an A1C of 5.7 to 6.4% (E), especially for those with a body mass index (BMI) >35 kg/m², age <60 years, and women with prior gestational diabetes mellitus (GDM). (A)
• At least annual monitoring for the development of diabetes in those with prediabetes is suggested. (E)

Definitions:

American Diabetes Association's Evidence Grading System for Clinical Practice Recommendations

A

Clear evidence from well-conducted, generalizable randomized controlled trials (RCTs) that are adequately powered, including:

• Evidence from a well-conducted multicenter trial
• Evidence from a meta-analysis that incorporated quality ratings in the analysis

Compelling nonexperimental evidence (i.e., "all or none" rule developed by the Centre for Evidence-Based Medicine at Oxford)

Supportive evidence from well-conducted RCTs that are adequately powered, including:

• Evidence from a well-conducted trial at one or more institutions
• Evidence from a meta-analysis that incorporated quality ratings in the analysis

B

Supportive evidence from well-conducted cohort studies, including:

• Evidence from a well-conducted prospective cohort study or registry
• Evidence from a well-conducted meta-analysis of cohort studies

Supportive evidence from a well-conducted case-control study

C

Supportive evidence from poorly controlled or uncontrolled studies, including:

• Evidence from RCTs with one or more major or three or more minor methodological flaws that could invalidate the results
• Evidence from observational studies with high potential for bias (such as case series with comparison to historical controls)
• Evidence from case series or case reports

Conflicting evidence with the weight of evidence supporting the recommendation

E

Expert consensus or clinical experience

None provided

The type of supporting evidence is identified and graded for each recommendation (see the "Major Recommendations" field).

Randomized controlled trials have shown that individuals at high risk for developing type 2 diabetes (those with impaired fasting glucose [IFG], impaired glucose tolerance [IGT], or both) can significantly decrease the rate of onset of diabetes with particular interventions. These interventions include intensive lifestyle modification programs that have been shown to be very effective (approximately 58% reduction after 3 years) and use of the pharmacologic agents metformin, α-glucosidase inhibitors, orlistat, and thiazolidinediones, each of which has been shown to decrease incident diabetes to various degrees.

Not stated

While numerous interventions to improve adherence to the recommended standards have been implemented, a major barrier to optimal care is a delivery system that too often is fragmented, lacks clinical information capabilities, often duplicates services, and is poorly designed for the coordinated delivery of chronic care. The Chronic Care Model (CCM) includes six core elements for the provision of optimal care of patients with chronic disease: 1) delivery system design (moving from a reactive to a proactive care delivery system, where planned visits are coordinated through a team-based approach; 2) self-management support; 3) decision support (basing care on evidence-based, effective care guidelines); 4) clinical information systems (using registries that can provide patient-specific and population-based support to the care team); 5) community resources and policies (identifying or developing resources to support healthy lifestyles); and 6) health systems (to create a quality-oriented culture). Redefinition of the roles of the clinic staff and promoting self-management on the part of the patient are fundamental to the successful implementation of the CCM. Collaborative, multidisciplinary teams are best suited to provide such care for people with chronic conditions like diabetes and to facilitate patients' performance of appropriate self-management.

National Diabetes Education Program (NDEP) maintains an online resource (www.betterdiabetescare.nih.gov ) to help health care professionals design and implement more effective health care delivery systems for those with diabetes.

Three specific objectives are outlined below.

Objective 1: Optimize Provider and Team Behavior

The care team should prioritize timely and appropriate intensification of lifestyle and/or pharmaceutical therapy of patients who have not achieved beneficial levels of blood pressure, lipid, or glucose control. Strategies such as explicit goal setting with patients; identifying and addressing language, numeracy, or cultural barriers to care; integrating evidence-based guidelines and clinical information tools into the process of care; and incorporating care management teams including nurses, pharmacists, and other providers have each been shown to optimize provider and team behavior and thereby catalyze reduction in glycosylated hemoglobin (A1C), blood pressure, and low-density lipoprotein (LDL) cholesterol.

Objective 2: Support Patient Behavior Change

Successful diabetes care requires a systematic approach to supporting patients' behavior change efforts, including (a) healthy lifestyle changes (physical activity, healthy eating, nonuse of tobacco, weight management, effective coping), (b) disease self-management (medication taking and management, self-monitoring of glucose and blood pressure when clinically appropriate); and (c) prevention of diabetes complications (self-monitoring of foot health, active participation in screening for eye, foot, and renal complications, and immunizations). High-quality diabetes self-management education (DSME) has been shown to improve patient self-management, satisfaction, and glucose control, as has delivery of ongoing diabetes self-management support (DSMS) so that gains achieved during DSME are sustained. National DSME standards call for an integrated approach that includes clinical content and skills and behavioral strategies (goal-setting, problem solving) and addresses emotional concerns in each needed curriculum content area.

Objective 3: Change the System of Care

The most successful practices have an institutional priority for providing high quality of care. Changes that have been shown to increase quality of diabetes care include basing care on evidence-based guidelines, expanding the role of teams and staff, redesigning the processes of care, implementing electronic health record tools, activating and educating patients, and identifying and/or developing and engaging community resources and public policy that support healthy lifestyles. Recent initiatives such as the Patient Centered Medical Home show promise to improve outcomes through coordinated primary care and offer new opportunities for team-based chronic disease care. Alterations in reimbursement that reward the provision of appropriate and high quality care rather than visit-based billing, and that can accommodate the need to personalize care goals, may provide additional incentives to improve diabetes care.

It is clear that optimal diabetes management requires an organized, systematic approach and involvement of a coordinated team of dedicated health care professionals working in an environment where patient-centered high-quality care is a priority.

Not applicable: The guideline was not adapted from another source.

American Diabetes Association (ADA)

Professional Practice Committee

Committee Members: Roger Anderson, MS, RPH, CDE; Susan Braithwaite, MD; Martha Funnell, MSN, RN, CDE; Robert Gabbay, MD; Richard Grant, MD, MPH; Jane Kadohiro, DrPH, APRN, CDE; James Lenard, MD; Daniel Lorber, MD; Michelle Magee, MD; Sunder Mudaliar, MD; Patrick O'Connor, MD, MPH; R. Harsha Rao, MD; Andrew Rhinehart, MD, CDE; Stuart Weinzimer, MD; Carol Wysham, MD (Chair); Gretchen Youssef, MS, RD, CDE; Judy Fradkin, MD (Ex officio); Stephanie Dunbar, RD, MPH (Staff); Sue Kirkman, MD (Staff)

Members of the Professional Practice Committee disclose all potential financial conflicts of interest with industry.

Members of the committee, their employer, and their disclosed conflicts of interest are listed in the "Professional Practice Committee Members" table and are available from the American Diabetes Association (ADA) Web site (see the "Availability of Companion Documents" field).

This is the current release of the guideline.

This guideline updates a previous version: American Diabetes Association (ADA). Standards of medical care in diabetes. IV. Prevention/delay of type 2 diabetes. Diabetes Care 2011 Jan;34(Suppl 1):S16.

Electronic copies: Available from the Diabetes Care Journal Web site .

Print copies: Available from the American Diabetes Association, 1701 North Beauregard Street, Alexandria, VA 22311.

The following are available:

• Introduction. Diabetes Care 2012 Jan;35(Suppl 1):S1-S2.
• Summary of revisions for the 2012 clinical practice recommendations. Diabetes Care 2012 Jan;35(Suppl 1):S3.
• Executive summary: standards of medical care in diabetes. Diabetes Care 2012 Jan;35(Suppl 1):S4-S10.
• Diagnosis and classification of diabetes mellitus. Diabetes Care 2012 Jan;35(Suppl 1):S64-S71.
• Third-party reimbursement for diabetes care, self-management education, and supplies. Diabetes Care 2012 Jan;35(Suppl 1):S99-100.
• Professional Practice Committee 2012 (includes conflict of interest disclosure). Diabetes Care 2012 Jan;35(Suppl 1):S109-S110.

Electronic copies: Available from the Diabetes Care Journal Web site .

Print copies: Available from the American Diabetes Association, 1701 North Beauregard Street, Alexandria, VA 22311.

The following is also available:

• 2012 Standards of medical care in diabetes. Clinical practice recommendations. Slide set. American Diabetes Association; 2012 Jan. 150 p. Electronic copies: Available from the American Diabetes Association (ADA) Web site .

None available

This summary was completed by ECRI on July 29, 2003. The summary was updated by ECRI on March 23, 2004, on July 1, 2005, March 16, 2006, April 30, 2007. This summary was updated by ECRI Institute on March 31, 2008. The updated information was verified by the guideline developer on May 15, 2008. This summary was updated by ECRI Institute on May 20, 2010. The information was verified by the guideline developer on May 25, 2010. This summary was updated by ECRI Institute on July 20, 2010 following the U.S. Food and Drug Administration advisory on Orlistat. This summary was updated by ECRI Institute on February 25, 2011. This NGC summary was updated by ECRI Institute on May 10, 2012.

This NGC summary is based on the original guideline, which is copyrighted by the American Diabetes Association (ADA).

For information on guideline reproduction, please contact Alison Favors, Manager, Rights and Permissions by e-mail at permissions@diabetes.org.

For information about the use of the guidelines, please contact the Clinical Affairs Department at (703) 549-1500 ext. 1692.