Abstract
Polypharmacy with "potentially inappropriate medications" (PIMs) and "potential prescribing omissions" (PPOs) are frequent among those 65 and older. We assessed PIMs and PPOs in a retrospective study of 82,935 patients ≥ 65 during their first admission in the period March 2013 through February 2018 to the four acute-care Calgary hospitals. We used the American Geriatric Society (AGS) and STOPP/START criteria to assess PIMs and PPOs. We computed odds ratios (ORs) for key outcomes of concern to patients, their families, and physicians, namely readmission and/or mortality within six months of discharge, and controlled for age, sex, numbers of medications, PIMs, and PPOs. For readmission, the adjusted OR for number of medications was 1.09 (1.09-1.09), for AGS PIMs 1.14 (1.13-1.14), for STOPP PIMs 1.15 (1.14-1.15), for START PPOs 1.04 (1.02-1.06), and for START PPOs correctly prescribed 1.16 (1.14-1.17). For mortality within 6 months of discharge, the adjusted OR for the number of medications was 1.02 (1.01-1.02), for STOPP PIMs 1.07 (1.06-1.08), for AGS PIMs 1.11 (1.10-1.12), for START PPOs 1.31 (1.27-1.34), and for START PPOs correctly prescribed 0.97 (0.94-0.99). Algorithm rule mining identified an 8.772 higher likelihood of mortality with the combination of STOPP medications of duplicate drugs from the same class, neuroleptics, and strong opioids compared to a random relationship, and a 2.358 higher likelihood of readmission for this same set of medications. Detailed discussions between patients, physicians, and pharmacists are needed to improve these outcomes.