Introduction: Many elderly people are multimorbid and are treated with five or more medications (polypharmacy) at the same time. Due to age related physiological changes they are especially vulnerable to adverse drug reactions (ADR). Potentially inappropriate prescriptions (PIPs) lead to increased adverse events like falls, hospitalizations and mortality. Up to 16% of unplanned hospitalizations of elderly people with polypharmacy are caused by ADRs. The primary aim of this study is the evaluation of the effectivity of a multi-component-intervention to reduce the frequency of ADRs in multimorbid patients aged 70 years and older.~Methods: We are planning a multi-center stepped wedge cluster randomized controlled trial at 40 primary care practices affiliated to the RaPHaeL-network (Research Practices Halle-Leipzig) in Saxony-Anhalt and Saxony, Germany. The planned intervention follows the recommendations of the New Medical Research Council and comprises a pharmacological medication plan review according to the STOPP/START-criteria and an adherence support measure employing motivational interviewing. Control group will receive usual care. Eligible patients are ≥ 70 years old, are diagnosed with three or more chronic medical conditions and are prescribed five or more medications. The primary outcome is the rate of ADRs six months post intervention. The secondary outcomes are number of ADRs, hospitalization rate due to ADRs, medication adherence (Morisky Adherence Score MMAS-8), the health-related quality of life (Euro-QOL EQ-5D-5L), the number of PIPs (according to STOPP/START), number of primary care physician per quarter, the medication appropriateness index and the mean number of de-prescriptions per patient. The planned sample size is 1,146 patients.~Discussion: Multimorbid patients with polypharmacy show an increased risk for PIPs, since prescriptions can be based on evidence for pharmacological therapy of a single condition without taking into account the complex drug interactions. Based on the existing evidence we are aiming to reduce ADRs in this patient population.
Elderly GP patients are often treated with five or more medications and therefore prone to adverse drug reactions (ADR). Potentially inappropriate prescriptions (PIPs) lead to increased adverse events like falls, hospitalizations and mortality. The primary aim of this study to reduce the frequency of ADRs in multimorbid patients aged 70 years and older by reducing polypharmacy.