Burden of comorbid medical conditions and quality of diabetes care

UMMS Affiliation

Department of Quantitative Health Sciences

Publication Date


Document Type



Aged; Alabama; Comorbidity; Cost of Illness; Diabetes Complications; Hemoglobin A, Glycosylated; Humans; Lipids; Medicare; Quality Assurance, Health Care; Reimbursement Mechanisms; United States


Bioinformatics | Biostatistics | Epidemiology | Health Services Research


OBJECTIVE: With performance-based reimbursement pressures, it is concerning that most performance measurements treat each condition in isolation, ignoring the complexities of patients with multiple comorbidities. We sought to examine the relationship between comorbidity and commonly assessed services for diabetic patients in a managed care organization.

RESEARCH DESIGN AND METHODS: In 6,032 diabetic patients, we determined the association between the independent variable medical comorbidity, measured by the Charlson Comorbidity Index (CCI), and the dependent variables A1C testing, lipid testing, dilated eye exam, and urinary microalbumin testing. We calculated predicted probabilities of receiving tests for patients with increasing comorbid illnesses, adjusting for patient demographics.

RESULTS: A1C and lipid testing decreased slightly at higher CCI: predicted probabilities for CCI quartiles 1, 2, 3, and 4 were 0.83 (95% CI 0.70-0.91), 0.83 (0.69-0.92), 0.82 (0.68-0.91), and 0.78 (0.61-0.88) for A1C, respectively, and 0.82 (0.69-0.91), 0.81(0.67-0.90), 0.79 (0.64-0.89), and 0.77 (0.61-0.88) for lipids. Dilated eye exam and urinary microalbumin testing did not differ across CCI quartiles: for quartiles 1, 2, 3, and 4, predicted probabilities were 0.48 (0.33-0.63), 0.54 (0.38-0.69), 0.50 (0.34-0.65), and 0.50 (0.34-0.65) for eye exam, respectively, and 0.23 (0.12-0.40), 0.24 (0.12-0.42), 0.24 (0.12-0.41), and 23 (0.11-0.40) for urinary microalbumin.

CONCLUSIONS: Services received did not differ based on comorbid illness burden. Because it is not clear whether equally aggressive care confers equal benefits to patients with varying comorbid illness burden, more evidence confirming such benefits may be warranted before widespread implementation of pay-for-performance programs using currently available "one size fits all" performance measures.

DOI of Published Version



Diabetes Care. 2007 Dec;30(12):2999-3004. Epub 2007 Aug 23. Link to article on publisher's site

Journal/Book/Conference Title

Diabetes care

PubMed ID


Related Resources

Link to Article in PubMed