Percent Time in Range with XXXX as a Performance Measure: How Long a Sampling Frame Is Needed?

@entity1 @entity1229
BACKGROUND: @entity1229 is received by millions of @entity1 in the United States and elsewhere and will remain the most commonly used anticoagulant for the foreseeable future. Percent time in therapeutic range (TTR) with @entity1229 is increasingly used as a performance measure. However, stakeholders have expressed concern that TTR lags behind changes in performance. Work in a larger study focused on the impact of shortening the conventional measurement period for TTR. METHODS: Some 124 sites within the Department of Veterans Affairs (VA) were examined during a seven-year period (fiscal years [FYs] 2008-2014 (April 1, 2007-September 30, 2014). The duration of time segments (2, 3, 4, 6 months) used to calculate TTR were varied, and these four durations were compared in terms of the number of @entity1 retained per site, mean and median site TTR, and site performance rankings. RESULTS: Data were obtained on 295,237 unique @entity1 who received anticoagulation. As the calculation window shortened, @entity1 with better control (that is, higher TTR) were selectively excluded from the measurement because their laboratory values were more widely spaced. Site mean TTR was highest when the most @entity1 were included (6 months: 950 @entity1 ; TTR 65.2%) and lowest when the fewest @entity1 were included (2 months: 567 @entity1 ; TTR 60.0%). However, the 3-, 4-, and 6-month segments achieved similar results, each of which included more than 800 @entity1 per site, with mean TTR across a narrow range (64.9%-65.2%). Site rankings were less highly correlated between the 2-month period and longer periods (r = 0.7- 0.8) but were otherwise 0.95 or higher, with a nearly perfect correlation (0.985) between the 4- and 6-month periods. CONCLUSIONS: When TTR is used to measure site-level performance, comparable results can be achieved using a 4- or a 6-month measurement period. On the basis of these results, the use of a 4-month period for future measurement efforts is recommended.
