Pharmaceutical policies: effects of cap and co-payment on rational use of medicines.

Growing expenditures on prescription medicines represent a major challenge to many health systems. Cap and co-payment policies are intended as an incentive to deter unnecessary or marginal utilisation, and to reduce third-party payer expenditures by shifting parts of the financial burden from insurers to patients, thus increasing their financial responsibility for prescription medicines. Direct patient payment policies include caps (maximum numbers of prescriptions or medicines that are reimbursed), fixed co-payments (patients pay a fixed amount per prescription or medicine), co-insurance (patients pay a percentage of the price), ceilings (patients pay the full price or part of the cost up to a ceiling, after which medicines are free or are available at reduced cost) and tier co-payments (differential co-payments usually assigned to generic and brand medicines). This is the first update of the original review.