OBJECTIVES: The defining characteristics of a disease condition are the same across all countries. Therefore, we hypothesize that when assessing a new treatment, via a clinical trial, we would expect different countries to value the same outcomes irrespective of where the trial was completed. We chose three disease conditions that are identified by exact biomarkers to test this hypothesis.   METHODS: We collected all open, actively enrolling, phase III drug studies from www.clinicaltrials.gov for Multiple Sclerosis, Hepatitis C, and HIV. After eliminating non-interventional studies and studies with missing information, we were left with 39 Multiple Sclerosis, 33 HIV, and 40 Hepatitis C trials. We defined three study locations: “U.S. only,” “ex-U.S. only,” and “U.S. and ex-U.S.” Among Multiple Sclerosis studies, 13 were U.S.-only, 15 ex-U.S. only, and 11 were U.S. and ex-U.S. Among HIV studies, 3 were U.S.-only, 19 ex-U.S. only, and 11 were U.S. and ex-U.S. Among Hepatitis C studies none were U.S. only, 23 ex-U.S., and 17 were U.S. and ex-U.S. Fisher’s exact test was used to examine associations between study locations and types of clinical trial outcomes measured.     RESULTS: We found no statistically significant differences in the outcomes evaluated by Multiple Sclerosis studies or HIV studies. Four of the 11 Hepatitis C outcome categories evaluated different outcomes depending on location: Sustained Virologic Response Week 12 (p-value 0.0011), Laboratory (p-value 0.0525), AEs (p-value 0.0235), and Safety (p-value 0.0227).    CONCLUSIONS: Our results support our hypothesis for two of the three conditions we examined, Multiple Sclerosis and HIV. However, for Hepatitis C, we found that clinical trials outcomes differ by location. The recent surge in development in Hepatitis C drugs may explain the discrepancy; however, further research and more data is needed.