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. 2018 May 8;20(5):e166. doi: 10.2196/jmir.9579

Table 5.

Group comparisons and interactions between both factors.

Characteristics Group difference: chat no versus yesa,b Group difference: 28 versus 50 daysa,b Interaction factor 1×factor 2×timea,c

Beta (95% CI) P value Effect size d (95% CI) Beta (95% CI) P value Effect size d (95% CI) Beta (95% CI) P value
Cannabis used (days), mean (SD)







Baseline −.02 (−0.14 to 0.10) .74 N/Ae −.09 (−0.23 to 0.05) .20 N/A −.01 (−0.18 to 0.16) .91

3 months N/A N/A 0.10 (−0.07 to 0.27) N/A N/A 0.15 (−0.02 to 0.32) N/A N/A

6 months N/A N/A 0.07 (−0.10 to 0.24) N/A N/A 0.18 (0.01 to 0.35) N/A N/A

12 months N/A N/A 0.10 (−0.07 to 0.27) N/A N/A 0.17 (0.00 to 0.35) N/A N/A
Cannabis used (number of events), mean (SD)






Baseline −.05 (−0.25 to 0.16) .64 N/A −.09 (−0.31 to 0.13) .43 N/A −.03 (−0.30 to 0.24) .82

3 months N/A N/A 0.10 (−0.07 to 0.27) N/A N/A 0.09 (−0.08 to 0.26) N/A N/A

6 months N/A N/A 0.05 (−0.12 to 0.22) N/A N/A 0.09 (−0.08 to 0.26) N/A N/A

12 months N/A N/A 0.06 (−0.11 to 0.23) N/A N/A 0.09 (−0.08 to 0.26) N/A N/A
Cannabis used (grams), mean (SD)







Baseline .01 (−0.17 to 0.19) .88 N/A −.04 (−0.23 to 0.15) .70 N/A −.05 (−0.27 to 0.18) .69

3 months N/A N/A 0.06 (−0.11 to 0.23) N/A N/A 0.02 (−0.15 to 0.19) N/A N/A

6 months N/A N/A 0.00 (−0.17 to 0.17) N/A N/A 0.09 (−0.08 to 0.26) N/A N/A

12 months N/A N/A −0.06 (−0.23 to 0.11) N/A N/A 0.01 (−0.16 to 0.18) N/A N/A
Cannabis dependence (SDSf), mean (SD)






Baseline −.02 (−0.09 to 0.05) .63 N/A −.02 (−0.0 to 0.05) .57 N/A .01 (−0.09 to 0.10) .91

3 months N/A N/A 0.14 (−0.03 to 0.31) N/A N/A −0.10 (−0.27 to 0.07) N/A N/A

6 months N/A N/A 0.11 (−0.06 to 0.28) N/A N/A −0.04 (−0.21 to 0.13) N/A N/A

12 months N/A N/A 0.06 (−0.11 to 0.23) N/A N/A 0.00 (−0.17 to 0.17) N/A N/A
Working alliance (WAI-srg), mean (SD)






3 months .36 (0.09 to 0.63) .008 0.22 (0.05 to 0.39) −.05 (−0.32 to 0.22) .71 −0.21 (−0.38 to −0.04) −.27 (−0.64 to 0.09) .15
Treatment satisfaction (CSQ-8>h), mean (SD)






3 months .33 (0.14 to 0.52) .001 0.34 (0.17 to 0.51) −.03 (−0.21 to 0.16) .76 −0.17 (−0.34 to 0.00) −.16 (−0.42 to 0.10) .22

aIntention-to-treat analyses following multiple imputation. Results of the nonimputed datasets can be found in Multimedia Appendix 3.

bBetween-group comparisons were conducted with the interaction of each factor with time, except for the effects on WAI-sr and CSQ-8 which were analyzed with the main effect of each factor.

cEffects on WAI-sr and CSQ-8 were analyzed with the interaction between factor 1 and factor 2.

dDuring the past 30 days.

eN/A: not applicable.

fSDS: Severity of Dependence Scale.

gWAI-sr: Working Alliance Inventory-short revised.

hCSQ-8: Client Satisfaction Questionnaire.