Relationship Between the
Chronic Care Model and
Diabetes Outcomes
Laurie Hurowitz, PhD,
Benjamin Littenberg, MD, and
Charles D. MacLean, MDCM
Context: Chronic Illness Care
• Current health care services are designed
to deliver acute care
• Need to redesign health care to deliver:
– more effective preventive services
Informed, Activated
Patient
Prepared, Proactive
Practice Team
Productive Interactions
Delivery System Design
Clinical Information Systems
Decision Support
Self-Management Support
Community
Resources
& Policies
The Chronic Care Model (CCM)
Health
System
Organization
Organization
of Care
Current Research CCM & Outcomes
• Most research has focused on elements of
the CCM and outcomes, and not the
model as a whole.
• Clinical Tool: Assessment of Chronic
Illness Care – pre/post measure, sensitive
to organizational change.
Research Question
What is the relationship between primary care
practice organization across all components of
the Chronic Care Model and glycemic control
for patients with diabetes?
Methods
• Design - Cross-sectional, observational study
• Subjects - Adults diagnosed with diabetes in
care in primary care practices in a rural VT, NH,
and NY.
Predictor Measure
The Assessment of Diabetes Care, adapted from
the Assessment of Chronic Illness Care version 3.5
(organizational change - organizational status)
•33 prompts/stems
•12-point response scale – descriptors provided
•Subscale scores (0-11); overall score is average (0-11)
•Practice average – average across all practitioners
Higher scores are associated with greater
conformance with the CCM.
Overall Goals for Diabetes Care (circle one) :
0 1 2 3 4 5 6 7 8 9 10 11
Do not exist. Exist but are not Are measurable Are measurable, reviewed
actively reviewed. and reviewed. routinely, and incorporated
into plans for improvement.
Sample Item
Glycosylated hemoglobin, as measured by
the A1C assay (A1C)
Source:
• adult patients diagnosed with diabetes
• Practice average - baseline measure from the
Vermont Diabetes Information System (VDIS)
For patients with diabetes, lower A1Cs are
associated with better clinical outcomes.
Even small decreases are related to
improving the burden of diabetes.
Results
Practice Characteristics
N=30
# of Practices w/ one PCP completing
ADC (% VDIS)*
30 (48%)
# of PCPs completing the ADC Survey
(% of total in VDIS)*
50 (40%)
Number of PCPs/Practice
Completing Survey
1 to 5
Average Number of Patients with
Diabetes/Practice (range)
98 (12-275)
Average ADC Score (range)
4.6 “basic”
Patient Characteristics*
(n=3,819)
Average Patient Age (yrs) (range among
practices)
61.2 (52-73)
% Male
51
Average A1C (mean practice range)
7.2 (6.4-8.2)
*This subset is 62% of the 6,124 patients participating in
VDIS at baseline. This subset did not differ significantly
from the group as a whole, by age or by gender.
Conformance with the CCM
& Diabetes Outcomes
Conformance with the CCM
& Diabetes Outcomes
Conformance with the CCM
& Diabetes Outcomes
Linear Regression (
N=30; n=3,819)
Regression results - Adjusting for age, the
relationship between the average ADC score and
glycemic control had a regression coefficient of
-0.11 (p=0.029; 95% CI -0.21 to -0.01).
Conclusions
Patients who receive care in practices that
conform to the Chronic Care Model have
better glycemic control.
This study lends support to the overall
validity of the Chronic Care Model and its
relationship to better outcomes for patients
with diabetes.
References
• Bodenheimer T, Wagner EH, Grumbach K. Improving primary care for patients with chronic illness. JAMA 2002, Oct 9; 288(14):1775-9 and Part 2. JAMA 2992 Oct 16:288(15):1909-14. • Bonomi AE, Wagner EH, Glasgow R, Vonkroff M. Assessment of chronic illness care: a practical
tool for quality improvement. Health Services Research. 2002; 37(3):791-820.
• MacLean CD, Littenberg B, Gagnon M, Reardon M, Turner PD and Jordan C. The Vermont Diabetes Information System (VDIS): study design and subject recruitment for a cluster
randomized trial of a decision support system in a regional sample of primary care practices. Clinical Trials. 2004;1:532-544.
• Shojania KG, Ranji SR, Shaw LK, Charo LN, Lai JC, Rushakoff RJ, McDonald KM, Owens DK. Diabetes mellitus care. Closing the quality gap: a critical analysis of quality improvement
strategies, Vol 2. Technical review 9, AHRQ Pub no. 04-0051-2. Rockville, MD. Sept 2004. • The Chronic Care Model and Clinical Tools. www.improvingchroniccare.org.
