Cross-cultural Adaptation and Validation of the Medication Regimen Complexity Index Adapted to Spanish.

BACKGROUND: The most widely used validated instrument to assess the complexity of medication regimens is the Medication Regimen Complexity Index (MRCI).

OBJECTIVE: This study aimed to translate, adapt, and validate a reliable version of the MRCI adapted to Spanish (MRCI-E).

METHODS: The cross-cultural adaptation process consisted of an independent translation by 3 clinical pharmacists and a backtranslation by 2 native English speakers. A reliability analysis was conducted on 20 elderly randomly selected patients. Two clinical pharmacists calculated the MRCI-E from discharge treatments and 2 months later. For the validity analysis, the sample was augmented to 60 patients. Convergent validity was assessed by analyzing the correlation between the number of medications; discriminant validity was stratified by gender; and predictive validity was determined by analyzing the ability to predict readmission and mortality at 3 and 6 months.

RESULTS: The MRCI-E retained the original structure of 3 sections. The reliability analysis demonstrated an excellent internal consistency (Cronbach's α=0.83), and the intraclass correlation coefficient exceeded 0.9 in all cases. The correlation coefficient with the number of medications was 0.883 ( P<0.001). No significant differences were found when stratified by gender (3.6; 95%CI=-2.9 to 10.2; P=0.27). Patients who were readmitted at 3 months had a higher MRCI-E score (10.7; 95%CI=4.4 to 17.2; P=0.001). The differences remained significant in patients readmitted at 6 months, but differences in mortality were not detected.

CONCLUSIONS: The MRCI-E retains the reliability and validity of the original index and provides a suitable tool to assess the complexity of medication regimens in Spanish.