The use of insulin declines as patients live farther from their source of care: results of a survey of adults with type 2 diabetes

BACKGROUND: Although most diabetic patients do not achieve good physiologic control, patients who live closer to their source of primary care tend to have better glycemic control than those who live farther away. We sought to assess the role of travel burden as a barrier to the use of insulin in adults with diabetes METHODS: 781 adults receiving primary care for type 2 diabetes were recruited from the Vermont Diabetes Information System. They completed postal surveys and were interviewed at home. Travel burden was estimated as the shortest possible driving distance from the patient's home to the site of primary care. Medication use, age, sex, race, marital status, education, health insurance, duration of diabetes, and frequency of care were self-reported. Body mass index was measured by a trained field interviewer. Glycemic control was measured by the glycosolated hemoglobin A1C assay. RESULTS: Driving distance was significantly associated with insulin use, controlling for the covariates and potential confounders. The odds ratio for using insulin associated with each kilometer of driving distance was 0.97 (95% confidence interval 0.95, 0.99; P = 0.01). The odds ratio for using insulin for those living within 10 km (compared to those with greater driving distances) was 2.29 (1.35, 3.88; P = 0.02). DISCUSSION: Adults with type 2 diabetes who live farther from their source of primary care are significantly less likely to use insulin. This association is not due to confounding by age, sex, race, education, income, health insurance, body mass index, duration of diabetes, use of oral agents, glycemic control, or frequency of care, and may be responsible for the poorer physiologic control noted among patients with greater travel burdens

Driving Distance as a Barrier to Glycemic Control in Diabetes

BACKGROUND: Despite advances in treatment of diabetes, many barriers to good glycemic control remain. OBJECTIVE: To determine the relationship between glycemic control and the driving distance from home to the site of primary care. DESIGN: Cross-sectional analysis of data from the Vermont Diabetes Information System. PARTICIPANTS: Nine-hundred and seventy-three adults with diabetes in primary care. The mean age was 64.9 years, 57% were female, and 18.4% used insulin. MEASUREMENTS: Hemoglobin A1c, shortest driving distance from a patient's home to the site of primary care calculated by geographic software, self-reported gender, age, education, income, marital status, race, insurance coverage, diabetic complications, and use of insulin and oral hypoglycemic agents. RESULTS: Controlling for social, demographic, seasonal, and treatment variables, there was a positive, significant relationship between glycemic control and driving distance (β=+0.07%/10 km, P <.001, 95% confidence interval [CI]=+0.03, +0.11). Driving distance had a stronger association with glycemic control among insulin users (β=+0.22%/10 km, P =.016, 95% CI=+0.04, +0.40) than among noninsulin users (β=+0.06%/10 km, P =.006, 95% CI=+0.02, +0.10). CONCLUSION: Longer driving distances from home to the site of primary care were associated with poorer glycemic control in this population of older, rural subjects. While the mechanism for this effect is not known, providers should be aware of this potential barrier to good glycemic control