Cost-related nonadherence to medications among patients with diabetes and chronic pain: Factors beyond finances

Abstract

OBJECTIVE - In the face of financial constraints, diabetic patients may forgo prescribed medications, causing negative health effects. This study examined how cost and noncost factors are associated with patterns of cost-related nonadherence to medications (CRN). RESEARCH DESIGN AND METHODS - This was a cross-sectional survey of patients using medications for both diabetes and chronic pain (n = 245). Patients reported their income, out-of-pocket medication costs, education level, depressive symptoms, and medication-related beliefs and whether they cut back because of cost on 1) both diabetes and pain medications, 2) diabetes medications only, 3) pain medications only, or 4) neither. Multinomial logistic regression was used to model patients' adjusted odds ratios (AORs) of falling into these four possible categories. RESULTS - Of the patients, 9% cut back on medications for both conditions, 13% cut back on diabetes medications alone, and 9% cut back on pain medications alone. Income <20,000 USD (AOR = 5.7, P = 0.008) and monthly medication costs >50 USD (AOR = 3.9, P = 0.02) increased patients' odds of CRN for both conditions versus neither. Low-income patients also were more likely to selectively forgo pain medications (AOR = 9.1, P = 0.001) but not diabetes medications (AOR = 2.1, P = 0.12). More depressive symptoms (AOR = 1.6, P = 0.006) and negative medication-related beliefs (AOR = 1.7, P = 0.02) increased patients' odds of cutting back selectively on medications for diabetes but not pain. CONCLUSIONS - Patients who forgo medications for both diabetes and chronic pain appear to be influenced primarily by economic pressures, whereas patients who cut back selectively on their diabetes treatments are influenced by their mood and medication beliefs. Our findings point toward more targeted strategies to assist diabetic patients who experience CRN. © 2009 by the American Diabetes Association.