Potentially inappropriate medications in older adults with Parkinson disease before and after hospitalization for injury

Background: Parkinson disease (PD) patients are at increased risk of serious injury, such as fall-related fractures. Prescription medications are a modifiable factor for injury risk.Objectives: To determine the extent to which a serious injury requiring hospitalization affects prescribing of potentially inappropriate medications (PIMs) among older adults with PD. Methods: We conducted a quasi-experimental difference-in-difference (DID) study using 2013-2017 Medicare data. The cohort consisted of beneficiaries with PD hospitalized for injury versus for other reasons. PIMs were classified into PD and injury-relevant categories (CNS-active PIMs, PD motor symptom PIMs, PD non-motor symptom PIMs, PIMs that reduce bone mineral density). We estimated mean standardized daily doses (SDDs) of medications within each PIM category before and at 3, 6, and 12 months after hospitalization. We used generalized linear regression models to compare changes in mean SDDs for each PIM category between the injury and non-injury group at each timepoint, adjusting for biological, clinical and social determinants of health variables. Results: Both groups discontinued PIMs and/or reduced PIM doses after hospitalization. There were no between -group differences in mean SDD changes, after covariate adjustment, for any PIM category, except for the CNS-active PIMs category at 3 months (DID p-value = 0.00) and for the category of PIMs that reduce bone mineral density at all timepoints (DID p-values = 0.02, 0.04, 0.02 at 3, 6, and 12 months).Conclusions: Similar patterns of PIM among persons with PD after hospitalization for serious injury versus for other reasons may represent a missed opportunity to deprescribe high-risk medications during care transitions.