The association between co-morbidity and the use of antidiabetics or adjunctive cardiovascular medicines in Australian veterans with diabetes.

Objective: To examine the association between co-morbidities and the use of antidiabetic medications or adjunctive cardiovascular medicines among Australian veterans with diabetes.
Methods: data were sourced from the Australian Department of Veterans' Affairs Health Claims database. All veterans aged 65 years and over who were dispensed medicines for diabetes from July to December 2006 were included. Dispensings of antidiabetic and adjunctive cardiovascular medicines over the first six months of 2007 were examined. Log binominal regression models were used to calculate the relative risks of the dispensing of medications for various co-morbidities, taking into account potential confounders.
Results: among the 14,802 veterans who were dispensed medicines for diabetes, 70% had five or more co-morbidities. Patients who had diabetes-related co-morbidities had significantly less dispensing of metformin monotherapy and more dispensing of insulin than those without these conditions. Patients who had cardiovascular disease were more likely to have three or more oral antidiabetics dispensed (RR=1.16, 95% CI: 1.04-1.30), particularly those who had heart failure (RR=1.24, 95% CI: 1.05-1.47). Patients with renal disease were more likely to have glitazones dispensed (RR=1.46, 95% CI: 1.24-1.72). Adjunctive cardiovascular medicines were significantly less likely to be dispensed to those with established heart conditions and non-related co-morbidities, particularly dementia.
Conclusions: consistent with guideline recommendations, in this cohort more intensive antidiabetic and cardiovascular therapy is used in those with more severe disease as measured by related co-morbidities. Cardiovascular medicines however may be underutilised in those with un-related co-morbidities.
(2010 Elsevier Ireland Ltd. All rights reserved.)