Delayed diagnosis of incident type 2 diabetes mellitus in the ARIC study

Objectives: To estimate delays to physician diagnosis of incident cases of type 2 diabetes mellitus (DM) and to identify predictors of delayed diagnosis. Study Design: The Atherosclerosis Risk in Communities (ARIC) study, an ongoing population-based prospective study of 15 792 middle-aged adults. Methods: The study population comprised 298 adults with incident DM. Exposures were demographic, socioeconomic, health behavior, and clinical risk factors before the onset of type 2 DM. The main outcome was the delay from onset of DM to physician diagnosis. Results: Among 298 ARIC participants with incident type 2 DM at visit 2 of the study, the median delay from onset of DM to physician diagnosis was 2.4 years. More than 7% of incident cases remained undiagnosed for at least 7.5 years after the onset of disease. Compared with individuals with promptly diagnosed incident DM, those with delayed diagnosis were more likely to be obese before the onset of DM (P = .003), less likely to have heart disease at baseline (P = .02 for trend), less likely to have seen their physician in the past year (P = .005 for trend), and had a slower rise in fasting hyperglycemia (P = .04). Neither demographic characteristics nor study site predicted delayed diagnosis. Conclusions: Even with a de facto screening program, diagnosis of incident type 2 DM in the community is typically delayed for 2 years and sometimes as long as 7 years or more. The associated risk factors suggest deficiencies in organizational processes, physician actions, and patient access or acceptance of the diagnosis.