Medication Regimen Complexity Index

The Medication Regimen Complexity Index (MRCI) is a clinician-administered quantitative measure that objectively assesses the complexity of a patient's medication regimen based on the number of medications, frequency of dosing, and form of administration. Developed by Morgado, Rolo, and Castelo-Branco in 2012, the MRCI quantifies an important adherence barrier—the complexity of taking multiple medications with different schedules and administration routes. The MRCI is unique among adherence tools in that it measures an objective regimen characteristic (not patient behavior or belief), making it useful for deprescribing decisions, medication reconciliation, and identifying high-risk patients for non-adherence due to complexity.