Out-of-Pocket Costs and Diabetes Preventive Services The Translating Research Into Action for Diabetes (TRIAD) study ANDREW J. KARTER, PHD 1 MARK R. STEVENS, MSPH, MA 2 WILLIAM H. HERMAN, MD, MPH 3 SUSAN ETTNER, PHD 4 DAVID G. MARRERO, PHD 5 MONIKA M. SAFFORD, MD 6 MICHAEL M. ENGELGAU, MD, MS 2 J. DAVID CURB, MD, MPH 7 ARLEEN F. BROWN, MD, PHD 4 THE TRIAD STUDY GROUP* OBJECTIVE — Despite the increased shifting of health care costs to consumers, little is known about the impact of financial barriers on health care utilization. This study investigated the effect of out-of-pocket expenditures on the utilization of recommended diabetes preventive services. RESEARCH DESIGN AND METHODS — This was a survey-based observational study (2000 –2001) in 10 managed care health plans and 68 provider groups across the U.S. serving 180,000 patients with diabetes. From 11,922 diabetic survey respondents, we studied the occurrence of self-reported annual dilated eye exams and diabetes health education and among insulin users, daily self-monitoring of blood glucose (SMBG). Conditional probabilities were estimated for outcomes at each level of self-reported out-of-pocket expenditure by using hier- archical logistic regression models with random intercepts. RESULTS — Conditional probabilities of utilization (95% CI) varied by expenditure for di- lated eye exam [no cost 78% (75– 82), copay 79% (75– 82), and full price 70% (64 –75); P  0.0001]; diabetes health education [no cost 29% (23–36), copay 29% (23–36), and full price 19% (14 –25); P  0.0001]; and daily SMBG [no cost 75% (68 – 81), copay 68% (60 –75), and full price 59% (49 – 68); P  0.0001]. Extensive adjustment for patient factors had no discernible effect on the estimates or their significance, and cost-utilization relationships were similar across income levels and other patient characteristics. CONCLUSIONS — Benefit packages structured to derive greater fiscal contribution from the health plan membership result in suboptimal use of diabetes preventive services and may thus lead to poorer clinical outcomes, greater future costs, and lower health plan quality ratings. Diabetes Care 26:2294 –2299, 2003 I n light of the trend toward shifting the burden of health care costs to the con- sumer, an understanding of how out- of-pocket expenditures impact use of diabetes preventive health care is needed. In recent years, managed care health plans are being driven by large employer purchasers toward offering lower cost products with increasing levels of cost sharing. Cost sharing, a common form of “demand management,” has been shown to reduce excessive utilization (1), yet there is relatively little known about its impact on diabetes service utilization. One concern is that the use of copays may unintentionally result in suboptimal use of essential care and medications, partic- ularly among the poor. Thus, cost sharing may become a self-defeating strategy if it poses financial barriers that lead to poorer health outcomes and greater future health care costs. For the most economically disadvan- taged patients, cost sharing has been as- sociated with reduced essential use of processes of care (2), medications (3), and self-care supplies (e.g., test strips for self- monitoring of blood glucose [SMBG]) (4). The magnitude of the effect of a financial barrier (price elasticity) may be modified by a patient’s socioeconomic status, be- cause fixed copays represent a greater burden for the poorest patients. Price elasticity may also vary depending on how patients value and prioritize the im- portance of health care versus personal cost saving (5). Both patient attributes (e.g., educational attainment and lan- guage abilities) and provider attributes (e.g., promotion of self-care activities and quality of provider-patient communica- tion) might further modify sensitivity to cost by imparting a better or worse under- standing of the value of the processes of care and self-management. To explore this issue, we studied whether higher out-of-pocket costs within the managed care setting (attribut- able to copayments, deductibles, or hav- ing to pay full price for services) were associated with lower use of three diabe- tes care processes that are recognized as standards of treatment: annual dilated eye exams, health education, and daily SMBG among insulin-treated diabetic patients. We hypothesized that the relationships between financial barriers and use of these processes of care may vary by pa- tient characteristics, particularly socio- economic position. ●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●● From the 1 Division of Research, Kaiser Permanente, Oakland, California; the 2 Centers for Disease Control and Prevention, Division of Diabetes Translation, Atlanta, Georgia; the 3 University of Michigan, School of Medicine, Ann Arbor, Michigan; the 4 University of California, Los Angeles, School of Medicine, Los Angeles, California; the 5 Indiana University School of Medicine, Indianapolis, Indiana; the 6 University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey; and the 7 Pacific Health Research Institute, Honolulu, Hawaii. Address correspondence and reprint requests to Andrew J. Karter, PhD, Division of Research, Kaiser Permanente, 2000 Broadway, Oakland, California 94612. E-mail: andy.j.karter@kp.org. Received for publication 13 February 2003 and accepted in revised form 21 April 2003. *See APPENDIX for a complete list of members of the TRIAD Study Group. Abbreviations: SMBG, self-monitoring of blood glucose; TRIAD, Translating Research Into Action for Diabetes. A table elsewhere in this issue shows conventional and Syste `me International (SI) units and conversion factors for many substances. © 2003 by the American Diabetes Association. Epidemiology/Health Services/Psychosocial Research O R I G I N A L A R T I C L E 2294 DIABETES CARE, VOLUME 26, NUMBER 8, AUGUST 2003