Adherence to perindopril/amlodipine/atorvastatin combination according to the administration strategy.

Aims: To compare adherence to perindopril/amlodipine/atorvastatin combination administrated as a polypill (one pill) vs separate tablets.

Methods: Using the healthcare utilization database of Lombardy (Italy), 1 110 patients who received the perindopril/amlodipine/atorvastatin polypill during 2019-2021 were matched with 1 110 patients prescribed the same combination in separate tablets or as two antihypertensive drugs in a single tablet and the lipid-lowering drug tablet separately. Adherence to treatment was assessed over the year after the first perindopril/amlodipine/atorvastatin dispensation as the proportion of the follow-up days covered by prescription (PDC). Patients with a PDC > 75% and < 25% were defined as highly and poorly adherent, respectively. Adherence dynamics over time were evaluated through group-based trajectory modelling. Cardiovascular-related healthcare costs were also assessed. Log-binomial regression models were fitted to estimate the risk ratio (RR) of treatment adherence associated with the administration strategy.

Results: Among the polypill and the separate-pill combination users, 60% and 18% of patients showed high adherence, respectively; the corresponding figures for the low adherence were 5% and 37%. Compared with the separate-pill combination, the polypill increased the propensity to be highly adherent to treatment by 3.29 times (95% confidence interval: 2.88-3.75) and reduced the low adherence risk (RR = 0.13, 0.10-0.18), irrespective of sex, age, comorbidities, and co-treatment burden also throughout the entire follow-up. The polypill was also associated with lower costs (€676 vs €1 068, p = 0.003).

Conclusions: In a real-life setting, the polypill improved treatment adherence and reduced healthcare costs compared to the corresponding separate-pill combination. These findings support current guidelines in favour of the polypill.