Underuse of cardioprotective treatment by the elderly with type 2 diabetes

To assess whether elderly patients with type 2 diabetes use a comprehensive cardioprotective regimen (CCR) of antihypertensive, lipid-lowering and antiplatelet drugs in the year following oral antidiabetic drug initiation and, if so, to identify the determinants of such use.

Using the Quebec Diabetes Surveillance System administrative database, we carried out an inception cohort study of individuals aged 66 years and over who began oral antidiabetic therapy between 1998 and 2002. Those individuals with at least one claim in the year after starting antidiabetic treatment for an antihypertensive, a lipid-lowering and an antiplatelet drugs were deemed to be using a CCR. A multivariate logistic regression model was built to identify the characteristics associated with CCR use.

Of the 48,505 individuals included in the study, 9912 (20.4%) used a CCR during the year following the first antidiabetic claim. Those more likely to use a CCR were men (odds ratio [OR]: 1.2; 99% confidence intervals [CI]: 1.1-1.3), those who had used an antihypertensive (1.6; 1.4-1.7), lipid-lowering (7.4; 6.8-8.0) or antiplatelet (7.3; 6.7-7.9) drug in the year before the first antidiabetic claim and those with a preexisting diagnosis of cardiovascular disease (1.9; 1.8-2.1). The odds of using a CCR increased every year.

CCR use by the elderly with type 2 diabetes in the year following antidiabetic initiation is low, and prior use of individual cardioprotective drugs is a strong predictor of its use. These findings suggest that the treatment of important modifiable risk factors for cardiovascular disease is suboptimal.