Sample Size Calculation
SECONDARY
To our knowledge, no previous studies have assessed time to attainment of a therapeutic TCA plasma concentration by pharmacogenetics-informed dosing according to DPWG guidelines. We assumed that 50% of the control group would reach a therapeutic plasma concentration within 4 weeks and that 50% of the PIT group would reach a therapeutic concentration within 2 weeks. Taking α = .05 and a power of 80% (2-sided log-rank test), a sample size of 44 patients per treatment group was required. For the secondary end points, we needed 63 patients per group (independent 