Screening criteria of potentially inappropriate medications and associations of exposure timing with incident hospital admissions among older adults in a rural community hospital

Limited studies consider resource disparity on the impact of potentially inappropriate medications (PIMs) in rural areas. This study aimed to explore PIMs prevalence and its characteristics using different screening criteria and examine the associations of incident hospital admissions and different PIM exposure timing for older adults living in a rural area. We conducted a retrospective cohort study to examine the one-year prevalence of PIM prevalence based on 2018 PIM-Taiwan and 2019 Beers criteria using the data retrieved from a local community hospital in a rural area during July 2018 to June 2019. We conducted a nested case-crossover study to evaluate the associations between PIM exposure in different exposure windows (most recent one-month versus 3 earlier control exposure periods) and the incident hospital admission by performing conditional logistic regressions. Of 8,234 older adult outpatients, 58% were exposed to at least one PIM (51.4% to PIM-Taiwan and 52.1% to Beers criteria). Of 384 older adult patients prescribed with medications and ever urgent hospital admissions, the most recent one-month exposure to PIM, and either or both criteria, as compared with the three earlier control periods, were statistically associated with incident hospital admissions but not for any class or individual PIMs, except Benzodiazepines (BZDs). Most recent one-month exposure to either criteria of PIM and BZDs are the significant factors associated with incremental incident hospital admissions. Further studies to investigate the undesired outcomes associated with expose timing of specific class of PIM(s) within older adult individuals in the underserved areas than urban areas to consider the health disparity for older adults are needed.