STOPP criteria and Beers' criteria for potentially inappropriate medications (PIMs), and START criteria for potential prescribing omissions (PPOs)

Potentially inappropriate medications or “PIMs” are highly prevalent in older people with multimorbid illness and associated polypharmacy. Polypharmacy is the principal risk factor for PIMs, and there is a known causal link connecting polypharmacy with adverse drug reactions (ADRs) and adverse drug events (ADEs) which are for the most part mediated by PIMs. For this reason, it is considered clinically important to detect PIMs during routine medication review. Potential prescribing omissions or “PPOs” are also clinically important to detect and assess as PPOs are also associated with adverse clinical outcomes in multimorbid older people. A careful balance between PIM and PPO avoidance is an important consideration in medication optimization in multimorbid older people experiencing polypharmacy.