. Author manuscript; available in PMC: 2017 May 10.

Published in final edited form as: Stat Med. 2015 Dec 6;35(10):1595–1615. doi: 10.1002/sim.6819

Table 2.

Design features of ExTENd study and their implications on modeling.

Design features	Implications for repeated-measures modeling
Randomization is (or should be) stratified on baseline measurements; there is no difference in anticipatory effect among the eight DTRs.	Trajectories of all the eight DTRs have the same intercept.
Patients became responders only if they stayed in stage one for eight weeks without meeting the assigned criterion for non-response. There can be no expectancy effects due to knowledge of second stage treatments during stage one.	A pair of DTRs that only differ in a₂_R (the second-stage treatment for responders) should share the same trajectory until the end of week eight, and may differ from then on.
Patients transitioned to stage two as non-responders as early as week two. There can be no expectancy effects due to knowledge of second stage treatments during stage one.	A pair of DTRs that only differ in a₂_NR (the second-stage treatment for non-responders) should share the same trajectory until the end of week two, and may differ from then on.