Table 2.

Causal estimands for the effect of sessions and alliance

	Estimate	s.e.	p	95% CI
(a) Evaluated when best alliance = 0
(1) SEM ignoring participants without data on both sessions and alliance
βS (effect of sessions at best alliance)	−2.66	0.76	0.000	−4.15 to −1.17
βSA (the interaction)	−1.44	0.50	0.004	−2.42 to −0.47
(2) SEM FIML including all participants’ data
βS (effect of sessions at best alliance)	−2.91	1.02	0.005	−4.91 to −0.90
βSA (the interaction)	−1.52	0.63	0.016	−2.76 to −0.29
(b) Evaluated when worst alliance = 0
(1) SEM ignoring participants without data on both sessions and alliance
βS (effect of sessions at worst alliance)	7.45	2.76	0.007	2.04 to 12.87
βSA (the interaction)	−1.45	0.50	0.004	−2.42 to −0.47
(2) SEM FIML including all participants’ data
βS (effect of sessions at worst alliance)	7.74	3.42	0.024	1.03 to 14.45
βSA (the interaction)	−1.52	0.63	0.016	−2.76 to −0.29

CI, Confidence interval; SEM FIML, structural equation modelling with full information maximum likelihood.