gms | German Medical Science

Forum Medizin 21, 45. Kongress für Allgemeinmedizin und Familienmedizin

Paracelsus Medizinische Privatuniversität in Zusammenarbeit mit der Deutschen, Österreichischen und Südtiroler Gesellschaft für Allgemein- und Familienmedizin

22.09. - 24.09.2011, Salzburg, Österreich

PIL: Polyfarmacy Intervention Limburg. A randomized controlled trial evaluating a complex intervention to optimize medication prescription, using the stepped wedge design

Meeting Abstract

45. Kongress für Allgemeinmedizin und Familienmedizin, Forum Medizin 21. Salzburg, 22.-24.09.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. Doc11fom070

doi: 10.3205/11fom070, urn:nbn:de:0183-11fom0706

Published: September 14, 2011

© 2011 van den Akker et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Background: Polypharmacy (the use of 5 or more drugs) is a relevant health problem among elder people. The proportion of people with polypharmacy is rising due to the prevalence of chronic diseases and aging of the population. Polypharmacy increases the risk of side-effects and problems with patient compliance. At the same time it may induce suboptimal treatment because the probability of underprescription increases with the number of drugs used, thus increasing the chance of inappropriate prescription. A significant part of chronic medication is prescribed within a specific medical specialism, often lacking an integrated view of indications, treatment goals and medication. The GP should play a pivotal role in the improvement of this process, with the availability of comprehensive data from his own practice, from the patient, the pharmacist and from other medical specialist. Furthermore, the GP is in a good position to discuss possibilities to change medication with the patient. The ultimate goal is to increase quality of life through optimization of the medication use of people with polypharmacy and to assure appropriate prescription, not to decrease the number of medications per se.

Material/Methods: This study uses the stepped wedge design, a special type of randomized controlled trial. Using this design all participating practices are offered the intervention at different moments in time. Participating practices are randomized into three groups: to start the intervention at T0, to start at T=3 months and to start at T=6 months. All patients must be included at T0, resulting in the collection of sufficient control time from the practices that have the intervention at T3 and T6. The intervention consists of an integral medication control and monitoring system. Data from the pharmacist are added to medical data from general practices (health problems, lab results and prescriptions) and information gathered through home visits by the nurse practitioner (actual use of medication). The general practitioner and pharmacist together make a medication advice, ask approval from involved hospital specialists and implement it in consultation with the patient.

Results: 21 general practices are participating in PIL, varying from single-handed practices to health care centres. Those practices have included around 800 patients. Part of those were included after T0.

Conclusions: For studies concerning highly actual topics, such as polypharmacy, it can be difficult to keep practices in the study when they are randomized in the control arm. The major advantage of a stepped wedge design is that all participating practices are guaranteed to have the intervention before the end of the project. It proved to be a problem to include all patients at T0, maybe due to the unfamiliarity of the participating practices with the design. Also for patients it appears to be difficult to contribute to data collection, before receiving the intervention.


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