Abstract Background To evaluate the U.K. Prospective Diabetes Study (UKPDS) and Framingham risk equations for predicting short-term risk of coronary heart disease (CHD) events among adults with long-standing type 2 diabetes, including those with and without preexisting CHD. Methods Prospective cohort of U.S. managed care enrollees aged ≥ 18 years and mean diabetes duration of more than 10 years, participating in the Translating Research into Action for Diabetes (TRIAD) study, was followed for the first occurrence of CHD events from 2000 to 2003. The UKPDS and Framingham risk equations were evaluated for discriminating power and calibration. Results A total of 8303 TRIAD participants, were identified to evaluate the UKPDS (n = 5914, 120 events), Framingham-initial (n = 5914, 218 events) and Framingham-secondary (n = 2389, 374 events) risk equations, according to their prior CHD history. All of these equations exhibited low discriminating power with Harrell’s c-index <0.65. All except the Framingham-initial equation for women and the Framingham-secondary equation for men had low levels of calibration. After adjsusting for the average values of predictors and event rates in the TRIAD population, the calibration of these equations greatly improved. Conclusions The UKPDS and Framingham risk equations may be inappropriate for predicting the short-term risk of CHD events in patients with long-standing type 2 diabetes, partly due to changes in medications used by patients with diabetes and other improvements in clinical care since the Frmaingham and UKPDS studies were conducted. Refinement of these equations to reflect contemporary CHD profiles, diagnostics and therapies are needed to provide reliable risk estimates to inform effective treatment.

Background

Versus whites, blacks with diabetes have poorer control of hemoglobin A1c (HbA1c), higher systolic blood pressure (SBP), and higher low-density lipoprotein (LDL) cholesterol as well as higher rates of morbidity and microvascular complications.

Objective

To examine whether several mutable risk factors were more strongly associated with poor control of multiple intermediate outcomes among blacks with diabetes than among similar whites.

Design

Case-control study.

Subjects

A total of 764 blacks and whites with diabetes receiving care within 8 managed care health plans.

Measures

Cases were patients with poor control of at least 2 of 3 intermediate outcomes (HbA1c > or =8.0%, SBP > or =140 mmHg, LDL cholesterol > or =130 mg/dL) and controls were patients with good control of all 3 (HbA1c <8.0%, SBP <140 mmHg, LDL cholesterol <130 mg/dL). In multivariate analyses, we determined whether each of several potentially mutable risk factors, including depression, poor adherence to medications, low self-efficacy for reducing cardiovascular risk, and poor patient-provider communication, predicted case or control status.

Results

Among blacks but not whites, in multivariate analyses depression (odds ratio: 2.28; 95% confidence interval: 1.09-4.75) and having missed medication doses (odds ratio: 1.96; 95% confidence interval: 1.01-3.81) were associated with greater odds of being a case rather than a control. None of the other risk factors were associated for either blacks or whites.

Conclusions

Depression and missing medication doses are more strongly associated with poor diabetes control among blacks than in whites. These 2 risk factors may represent important targets for patient-level interventions to address racial disparities in diabetes outcomes.