Eva Blozik, Roland Rapold, Oliver Reich

Drugs can be supplied either directly from the prescribing physician (physician dispensing [PD]) or via a pharmacy. It is unclear whether the dispensing channel is associated with quality problems. Potentially inappropriate medication (PIM) is associated with adverse outcomes in older persons and can be considered a marker for quality deficits in prescribing. We investigated whether prevalence of PIM differs across dispensing channels. We analyzed basic health insurance claims of 50,747 person quarter years with PIM use of residents of the Swiss cantons Aargau and Lucerne of the years 2012 and 2013. PIM was identified using the Beers 2012 criteria and the PRISCUS list. We calculated PIM prevalence stratified by supply channel. Adjusted mixed effects logistic regression analysis was done to estimate the effect of obtaining medications through the dispensing physician as compared to the pharmacy channel on receipt of PIM. The most frequent PIMs were identified. There is a small but detectable difference in total PIM prevalence: 30.7% of the population supplied by a dispensing physician as opposed to 29.3% individuals who received medication in a pharmacy. According to adjusted logistic regression individuals who obtained the majority of their medications from their prescribing physician had a 15% higher chance to receive a PIM (odds ratio 1.15, 95% confidence interval 1.08-1.22; P<0.001). Physician dispensing seems to affect quality and safety of drug prescriptions. Quality issues should not be neglected in the political discussion about the regulations on PD. Future studies should explore whether PD is related to other indicators of inefficiency or quality flaws. The present study also underlines the need for interventions to reduce the high rates of PIM prescribing in Switzerland.