OBJECTIVES : Medical home (MH) implementation in the Local Health Authority (LHA) of Parma, Emilia-Romagna, Italy, was associated with a reduction in potentially inappropriate medication (PIM) use among older adults. We examine heterogeneity in this association between early and late adopter MHs, and between the early and later post-implementation periods.

METHODS : We conducted a retrospective cohort study using the Parma LHA administrative healthcare database between 01/01/2011-12/31/2017. Adults ≥65 years who lived in Parma >1 year, had ≥1 medication dispensed, and had a documented primary care physician (PCP) were studied. PIM exposure was determined based on medications that should be always avoided according to the 2011 and 2014 Maio criteria, an Italian modified version of the Beers criteria. Exposure to MH care was time-varying and was operationalized using three levels (non-MH, pre-MH, and MH). Repeated events Cox proportional hazards models were used to compare rates of PIM for 1) early (2011-2012) versus late (after 2012) MH adopters and 2) first year versus later years after MH implementation.

RESULTS : Among the 129,938 elderly included, 22% of their total person-time was under exposure to MH. Overall, MH implementation was associated with a decreased rate of PIM use regardless of adoption status, (early MH adopters: post vs. pre, HR=0.89; 95% CI: 0.86-0.92; late MH adopters: post vs pre HR = 0.92; 95% CI 0.90-0.95). Additionally, improvement in PIM exposure over time was seen in MH, as the rate of PIM decreased after the first year in MH vs the first year in MH (HR =0.75; 95% CI: 0.73-0.77).

CONCLUSIONS : Our findings suggest that MH implementation can reduce PIM use for older adults regardless of when PCPs entered into a MH. Larger decreases among early adopters and those with longer experience in a MH suggests that performance improvement continues after the initial implementation period.