Validation of a patient-level medication regimen complexity index as a possible tool to identify patients for medication therapy management intervention

Pharmacotherapy. 2014 Aug;34(8):826-35. doi: 10.1002/phar.1452. Epub 2014 Jun 20.


Background: The Medication Regimen Complexity Index (MRCI) is a 65-item instrument that can be used to quantify medication regimen complexity at the patient level, capturing all prescribed and over-the-counter medications. Although the MRCI has been used in several studies, the narrow scope of the initial validation limits application at a population or clinical practice level.

Purpose: To conduct a MRCI validation pertinent to the desired clinical use to identify patients for medication therapy management interventions.

Methods: An expert panel of clinical pharmacists ranked medication regimen complexity for two samples of cases: a single-disease cohort (diabetes mellitus) and a multiple-disease cohort (diabetes mellitus, hypertension, human immunodeficiency virus infection, geriatric depression). Cases for expert panel review were selected from 400 ambulatory clinic patients, and each case description included data that were available via claims or electronic medical records (EMRs). Construct validity was assessed using patient-level MRCI scores, medication count, and additional patient data. Concordance was evaluated using weighted κ agreement statistic, and correlations were determined using Spearman rank-order correlation coefficient (ρ) or Kendall τ.

Results: Moderate to good concordance between patient-level MRCI scores and expert medication regimen complexity ranking was observed (claims data, consensus ranking: single-disease cohort 0.55, multiple disease cohort 0.63). In contrast, only fair to moderate concordance was observed for medication count (single-disease cohort 0.33, multiple-disease cohort 0.48). Adding more-detailed administration directions from EMR data did not improve concordance. MRCI convergent validity was supported by strong correlations with medication count (all cohorts 0.90) and moderate correlations with morbidity measures (e.g., all cohorts; number of comorbidities 0.46, Chronic Disease Score 0.46). Nonsignificant correlation of MRCI scores with age and gender (all cohorts 0.08 and 0.06, respectively) supported MRCI divergent validity.

Limitations: This study used cross-sectional, retrospective patient data for a small number of patients and clinical pharmacists from only two universities; therefore, results may have limited generalizability.

Conclusions: The patient-level MRCI is a valid tool for assessing medication regimen complexity that can be applied by using data commonly found in claims and EMR databases and could be useful to identify patients who may benefit from medication therapy management.

Keywords: HIV; MRCI; MTM; chronic disease; complexity; diabetes; geriatrics; human immunodeficiency virus; hypertension; medication regimen complexity; medication therapy management.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Ambulatory Care / methods
  • Cohort Studies
  • Cross-Sectional Studies
  • Diabetes Mellitus / drug therapy
  • Female
  • Humans
  • Male
  • Medication Therapy Management*
  • Middle Aged
  • Nonprescription Drugs / administration & dosage
  • Nonprescription Drugs / therapeutic use*
  • Pharmacists / organization & administration*
  • Prescription Drugs / administration & dosage
  • Prescription Drugs / therapeutic use*
  • Retrospective Studies
  • Statistics, Nonparametric


  • Nonprescription Drugs
  • Prescription Drugs