Trends and interaction of polypharmacy and potentially inappropriate prescribing in primary care over 15 years in Ireland: a repeated cross-sectional study.

Accounting for the marked increase in polypharmacy, prescribing quality appears to have improved with a reduction in the odds of having PIP from 1997 to 2012. With growing numbers of people taking multiple regular medicines, strategies to address the related challenges of polypharmacy and PIP are needed.