OBJECTIVES: The ENSEMBLE MDS is a battery of phenotypic generic patient-reported instruments designed for use in clinical studies or comparative effectiveness research. The component instruments assess baseline patient characteristics that are believed to be either predictors (health status, illness burden, depression, anxiety, and perceived stress) or effect-modifying factors (perceived social status, objective social status, perceived social support, income) of clinical outcomes and/or treatment response.  We sought to evaluate the equivalence of the MDS across two different modes of administration – paper and web. METHODS: This study was a data collection effort that used a randomized cross-over design in the United States (English) and Singapore (Simplified Chinese).  Participants were outpatients with a clinical diagnosis of one of five targeted health conditions: depression, type 2 diabetes, psoriasis, rheumatoid arthritis and chronic kidney disease. Those enrolled were randomized to initially complete the MDS on paper or web format, and returned 24 hours later to complete the alternate format.  Equivalence was evaluated by the intraclass correlation coefficient (ICC) with equivalency defined at or above the minimal acceptable level of 0.70.  These analyses were performed individually for each of the nine MDS component measures. RESULTS: A total of 314 participants (258 in US, 56 in Singapore) were analyzed. In the US, mean age was 49±13 years, 61% were female; in Singapore mean age was 57±12, 59% female.  The ICCs between paper and web administration of the different components of the ENSEMBLE MDS ranged between 0.74 and 0.98 in the US, and between 0.75 and 0.97 in Singapore. CONCLUSIONS: Equivalence between paper and web-based administration of the ENSEMBLE MDS was demonstrated statistically for the US-English Version and the Chinese version for Singapore, indicating stability of subject comprehension and response patterns across two modes of administration in two different languages and cultures.