The effect of tiered-copay formularies on prescription drug use and spending.
D003669:Deductibles and Coinsurance; D004358:Drug Therapy / Q000191:economics* / Q000706:statistics & numerical data*; D017723:Drug Utilization Review; D005569:Formularies as Topic; D006291:Health Policy; D006801:Humans; D008329:Managed Care Programs; D014481:United States