Abstract
Background: Pharmacoepidemiologic studies using claims databases show lower intensity of drug treatment for diabetes mellitus (DM) with older age and greater comorbidity, but do not account for level of glycemic control. The aim of this study is to describe patterns of hypoglycemic use among older adults with DM while controlling for patient-level factors, including glycemic control.
Methods: We conducted a cross-sectional study among enrollees of a mixed-model, not-for-profit HMO operating in New England. We identified 772 patients who were aged 65 years and older, had a diagnosis of type 2 diabetes mellitus from January 1 to December 31, 2002, and used at least one hypoglycemic medication. Information on age, sex, prescription drug dispensings, inpatient and outpatient diagnoses and procedures, and laboratory test results were obtained from HMO automated databases. Comorbidity burden was assessed by calculating the Chronic Disease Score based on prescription drug dispensings. We used multivariable logistic regression to identify the independent effect of age on intensity of hypoglycemic medication use (monotherapy vs multidrug or insulin therapy) while controlling for patient-level factors including glycemic control, Chronic Disease Score, and presence of coronary heart disease (CHD), hypertension and dyslipidemia.
Results: Overall, 541 (70.1%) used one oral hypoglycemic agent, 181 (23.5%) used two oral agents, 10 (1.3%) used three oral agents, and 26 (3.4%) used insulin therapy. In adjusted analysis, predictors of less aggressive (monotherapy) versus more aggressive (multidrug or insulin) therapy were older age (=85 yrs vs 65–74 yrs; odds ratio, 0.32; 95% CI, 0.15–0.67) and prior hospitalization (OR, 0.45; 95% CI, 0.25–0.80). Poorer glycemic control was associated with more aggressive hypoglycemic therapy (HgA1c >9 vs HgA1c <7; OR, 2.9; 95% CI, 1.3–6.5). History of CHD increased the likelihood of using more aggressive hypoglycemic therapy (OR, 1.6; 95% CI, 1.06–2.45).
Conclusions: Although prevalence and risk of complications from diabetes increases with age, intensity of drug treatment for diabetes declines with older age even after adjustment for glycemic control and comorbidity.
- Received September 11, 2008.
