What tools might be included in the design phase of the policy process to increase the probability of success?

The incidence of PolyPharmacy, or the use of five or more medications on a daily basis, is common in the US particularly among the elderly population. It occurs for a variety of reasons, including the need to treat multiple conditions, the patient obtaining treatment from numerous physicians, and a lack of communication among those physicians about medications prescribed. PolyPharmacy increases the risk of adverse drug effects and increased costs to patients. Formulate a policy to reduce the practice of multiple drug prescriptions. What tools might be included in the design phase of the policy process to increase the probability of success? What research from other countries could be helpful in addressing this issue?