Time in therapeutic range
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and Keywords: TTR
Overview
Factors Affecting Time in Therapeutic Range
Cross Trial Comparisons of TTR are hampered by variations in:
• CHADS Score: Higher the CHADS score, lower the TTR. Sicker patients may have reduced access to frequent testing.
• Age: Older patients may have reduced access to frequent testing
• CHF: Varying drug clearance and distribution (CHF: 63% in ROCKET, 32% RELY, 35% ARISTOTLE)
• Country: Highest in Scandanavia, lowest in developing countries
• What is the TTR in ROCKET AF in those countries who conducted RE-LY and vice versa (adjusting for the number of sites in each country)?
• Should trials only be conducted in countries with a high TTR or should sponsors conduct real world trials throughout the world?