Potentially Inappropriate Medication Use in Multimorbid Elderly Inpatients: Differences Between the FORTA, PRISCUS and STOPP Ratings

BACKGROUND Several classifications to identify and avoid use of potentially inappropriate medications (PIMs) in the elderly have been published. To what extent these classifications match each other and whether there are differences in the prevalence of PIM use at admission, during the inpatient stay and at discharge are largely unreported. OBJECTIVES To determine the PIM prevalence in elderly patients at a university hospital, with a special focus on different classification systems and the chronological sequence, and to examine a possible association between PIM use and the reason for admission, as well as severe side effects and consequences of PIM use during hospitalization. METHODS On the basis of the criteria provided by FORTA (Fit for the Aged), PRISCUS (Latin for 'time-honoured') and STOPP (Screening Tool of Older Persons' Potentially Inappropriate Prescriptions), medication in patients over the age of 65 years was screened retrospectively within four point prevalence analyses at admission, during the inpatient stay and at discharge. Evaluation of a possible association between PIM use and the primary diagnosis or severe side effects during hospitalization was performed according to an analysis using the World Health Organization Uppsala Monitoring Centre system for standardized case causality assessment. RESULTS Of 200 patients, 176 (88 %) received at least one PIM at admission, during the inpatient stay and/or at discharge (116 patients according to FORTA, 113 according to PRISCUS and 138 according to STOPP). When the PIM prevalence was compared between the three different sets of criteria, STOPP identified significantly more patients receiving PIMs than FORTA (P = 0.022) and PRISCUS (P = 0.010). At the patient level and at the drug level, the use of PIMs increased during the inpatient stay; however, the PIM prevalence was similar at admission and at discharge, both at the patient level and at the drug level. CONCLUSION Medication is rated significantly differently by FORTA, PRISCUS and STOPP. In addition, a significant rise in prescribing of PIMs during the inpatient stay illustrates that a reduction in PIM use during the inpatient stay is essential, as it is known that avoiding PIM use in older adults is one strategy to decrease the risk of adverse events.