Addressing medication complexity in outpatient care: are Multicompartment Compliance Aids enough?

Introduction Medication regimen complexity contributes to unintentional non-adherence, particularly in older adults and patients with chronic conditions. Multicompartment compliance aids (MCAs) are widely used to support adherence, but their real-world effectiveness in outpatients with high regimen complexity remains uncertain. Aim To evaluate the suitability of MCAs in outpatients with high medication regimen complexity using the Medication Regimen Complexity Index (MRCI). Method A cross-sectional study was conducted in five community pharmacies in Central Portugal (January–July 2023). Adults (>18 years), autonomous in medication management, were included. Medication data were collected through semi-structured interviews and analyzed using the MRCI. Each medicine was assessed for MCA suitability according to national and international guidelines. Associations between MRCI and MCA feasibility were analyzed using appropriate statistical tests (p < 0.05). Results Among 189 participants (64.6% female; median age 72 years), 94.7% were under polypharmacy and 23.8% under hyper-polypharmacy. The median number of medications was 7, and the median MRCI score was 26, with 51.9% at or above this threshold. MRCI strongly correlated with medication number (ρ = 0.918; p < 0.001). Although 79.4% of regimens were eligible for MCA inclusion, only 42.7% of eligible regimens were fully accommodated. Patients with lower MRCI scores had a 3.8-fold higher likelihood of full MCA inclusion (72.7% vs. 19.1%; χ² = 43.5; p < 0.001). Conclusion MCAs alone may be insufficient for patients with high regimen complexity. Combining MCA use with structured medication reviews and regimen simplification may improve adherence.