ORIGINAL ARTICLE The Health Effects of Restricting Prescription Medication Use Because of Cost Michele Heisler, MD, MPA,*†‡ Kenneth M. Langa, MD, PhD,*†§ Elizabeth L. Eby, MPH,* A. Mark Fendrick, MD,† Mohammed U. Kabeto, MS,† and John D. Piette, PhD*†‡ Background: High out-of-pocket expenditures for prescription medications could lead people with chronic illnesses to restrict their use of these medications. Whether adults experience adverse health outcomes after having restricted medication use because of cost is not known. Methods: We analyzed data from 2 prospective cohort studies of adults who reported regularly taking prescription medications using 2 waves of the Health and Retirement Study (HRS), a national survey of adults aged 51 to 61 in 1992, and the Asset and Health Dynamics Among the Oldest Old (AHEAD) Study, a national survey of adults aged 70 or older in 1993 (n = 7991). We used multivariable logistic and Poisson regression models to assess the independent effect on health outcomes over 2 to 3 years of follow up of reporting in 1995–1996 having taken less medicine than pre- scribed because of cost during the prior 2 years. After adjusting for differences in sociodemographic characteristics, health status, smok- ing, alcohol consumption, body mass index (BMI), and comorbid chronic conditions, we determined the risk of a significant decline in overall health among respondents in good to excellent health at baseline and of developing new disease-related adverse outcomes among respondents with cardiovascular disease, diabetes, arthritis, and depression. Results: In adjusted analyses, 32.1% of those who had restricted medications because of cost reported a significant decline in their health status compared with 21.2% of those who had not (adjusted odds ratio AOR, 1.76; confidence interval CI, 1.27–2.44). Re- spondents with cardiovascular disease who restricted medications reported higher rates of angina (11.9% vs. 8.2%; AOR, 1.50; CI, 1.09 –2.07) and experienced higher rates of nonfatal heart attacks or strokes (7.8% vs. 5.3%; AOR, 1.51; CI, 1.02–2.25). After adjusting for potential confounders, we found no differences in disease- specific complications among respondents with arthritis and diabe- tes, and increased rates of depression only among the older cohort. Conclusions: Cost-related medication restriction among middle- aged and elderly Americans is associated with an increased risk of a subsequent decline in their self-reported health status, and among those with preexisting cardiovascular disease with higher rates of angina and nonfatal heart attacks or strokes. Such cost-related medication restriction could be a mechanism for worse health outcomes among low-income and other vulnerable populations who lack adequate insurance coverage. Key Words: insurance, health care expenditures, prescription medications, chronic illness, health services accessibility (Med Care 2004;42: 626 – 634) B oth prescription drug use and expenditures have increased dramatically in the past decade, yet many American adults have either limited or no prescription drug insurance coverage. 1,2 In 1999, noninstitutionalized Medicare benefi- ciaries paid out-of-pocket for nearly half of their prescription drug costs, or an average of $410 per beneficiary. 3 Out-of- pocket prescription medication expenditures for adults with multiple chronic diseases are more than twice that amount. 4 A growing body of research has documented significant rates of underuse of medications as a result of the burden of out-of-pocket cost, especially among vulnerable popula- tions. 5–8 For example, Steinman et al. found that 8% of elderly people in the United States without drug coverage reported restricting medications because of cost, with rates as high as 16% among those with annual incomes less than $10,000 and 21% among nonwhites. 9 Patients faced with reduced prescription drug coverage fill fewer prescriptions, including those for medications essential for treating cardio- vascular disease and diabetes. 10 –16 The views expressed in this paper are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs. Dr. Heisler is a VA HSR&D Career Development Awardee. Dr. Langa was supported by a Career Development Award from the National Institute on Aging (K08 AG19180), a New Investigator Research Grant from the Alzheimer’s Association, and a Paul Beeson Physician Faculty Scholars in Aging Research award. From the *Veterans Affairs Center for Practice Management & Outcomes Research, VA Ann Arbor Healthcare System, Ann Arbor, Michigan; the †Department of Internal Medicine, ‡Michigan Diabetes Research and Training Center, the §Institute for Social Research, and the Patient Safety Enhancement Program, University of Michigan School of Medi- cine, Ann Arbor, Michigan. Reprints: Michele Heisler, MD, MPA, HSR&D Field Program, PO Box 130170, Ann Arbor, MI 48113-0170. E-mail: mheisler@umich.edu. Copyright © 2004 by Lippincott Williams & Wilkins ISSN: 0025-7079/04/4207-0626 DOI: 10.1097/01.mlr.0000129352.36733.cc Medical Care • Volume 42, Number 7, July 2004 626