Enrollment patterns in Medicare HMOs: implications for access to care.
D000368:Aged; D003657:Decision Making; D003669:Deductibles and Coinsurance / Q000706:statistics & numerical data; D006279:Health Maintenance Organizations / Q000706:statistics & numerical data*; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D006801:Humans; D006278:Medicare / Q000706:statistics & numerical data*; D011336:Probability; D012959:Socioeconomic Factors; D014481:United States