gms | German Medical Science

Background: The simultaneous use of multiple drugs increases the risk for interactions. When adding a new drug to an existing drug regime, the prescriber should not only know the current therapy of the patient but should also be aware on any patient-related factors, e.g. kidney function that might have an impact on the choice of or the dosing of the drug to be prescribed. The same applies to pharmacists when counselling patients regarding self-medication. It is evident that a higher number of physicians and pharmacies involved in the prescription process increases the risk of relevant information being lost along the way and increases the effort necessary to assemble an accurate medication plan.

The German law requires that physicians generate the federal (standardized) medication plan for all patients with a minimum of three prescribed medications for a duration of at least 28 days to optimize the flow of information and to enhance drug use safety.

The present study’s objective was to analyze how many different prescribers and pharmacies are involved in the prescription process of patients with polypharmacy. This was done on the basis of administrative or routine data of the German healthcare system.

Materials and methods: Database: BARMER health insurance data for 8.331.838 persons continually insured (or continually insured until death) in the year 2016. All drug ingredients (excluding topical preparations) were assessed by means of ATC-Code (7-digit). Combination drugs were separated into single components and coded with ATC. Definition of the treatment period: periods of drug use were estimated by using the date of drug pick-up at the pharmacy as a starting point and calculating the duration on the basis of the defined daily dose (DDD). Drugs delivered in the year 2015 were included when the coverage lasted into the year 2016. Definition of polypharmacy: simultaneous drug supply of five or more active ingredients (for at least one day).

Results: 12.1% of 2,025,967 insurees with polypharmacy received their prescription from only one prescriber, 34.4%, 57.3% and 74.8% from up to two, three or four prescribers, respectively. 40% of the insurees with polypharmacy received their prescriptions from one main prescriber – here defined as a physician issuing 75% or more of all prescriptions of one patient.

35.8% of patients with polypharmacy redeemed their prescriptions in only one pharmacy, 64.2% in up to two and 82.5% in up to three pharmacies. 70% of insurees with polypharmacy have chosen one pharmacy as the main one (“Stammapotheke”) – here defined as redeeming 75% of all prescriptions of one patient.

Conclusion: It is a limitation of this study that drug therapy has been analyzed based on medication reimbursed data of a health insurance company only. Self-medication and prescriptions not refunded are not included in the analysis. Nevertheless, the results clearly demonstrate that the majority of patients with polypharmacy get prescriptions from more than one prescriber and get their drugs from more than one pharmacy. These findings stress the importance of care coordination and communication between health care providers to achieve medication safety.

Acknowledgement: The study is part of the „BARMER Drug Report 2018 („Arzneimittelreport 2018“) and was financed by BARMER.