Between 1 in 4 and 1 in 25 people benefit from their prescribed medicines (Schork 2015). However, adverse drug reactions (ADRs, known as side effects) occur in 7.8% (7.2-8.4%) patients in community (or ambulatory) care (Hakkarainen et al 2013). Most of these are preventable (Hakkarainen et al 2013, NICE 2015). Adverse drug events (ADE), which include ADRs and under-prescribing, and medicines' mismanagement are responsible for 8% of healthcare spend in the USA, $213bn (Aitkin & Valkova 2013) and 9.5% of direct costs in Sweden.