Potentially inappropriate medication in the elderly in Germany: an economic appraisal of the PRISCUS list

BACKGROUND: Several lists of potentially inappropriate medication (PIM) for elderly patients have been developed worldwide in recent years. Those lists intend to reduce prescriptions of drugs that carry an unnecessarily high risk of adverse drug events in elderly patients. In 2010, an expert panel published the PRISCUS list for the German drug market. This study calculates the amount of drug reimbursement for PIM in Germany and potential cost effects from the perspective of statutory health insurance when these are replaced by the substitutes recommended by the PRISCUS list. METHODS: Register-based data for the 30 top-selling drugs on the PRISCUS list in 2009 for patients greater than or equal to 65 years of age were provided by the Scientific Institute of the German Local Health Care Fund. We calculated the percentage of sales and defined daily doses for patients greater than or equal to 65 years of age compared with the total statutory health insurance population. Reimbursement costs for the recommended substitutions were estimated by considering different scenarios. RESULTS: In 2009, drug reimbursement for the 30 top-selling PIM prescribed to patients greater than or equal to 65 years of age were calculated to be €305.7 million. Prescribing the recommended substitution medication instead of PIM would lead to an increased total reimbursement cost for the German health care system ranging between from €325.9 million to €810.0 million. CONCLUSIONS: The results show that the substitution of PIM by medication deemed to be more appropriate for the elderly comes along with additional costs. Consequently, there is no short-term incentive for doing so from a payer perspective. Future studies have to consider the long-term effects and other sectors.