Table 2. Mediation tests of putative mediators.
| Mediator Candidate | 3-months | 6-months | ||||
|---|---|---|---|---|---|---|
| Beta (SE) | ES1 | t or χ2 | Beta (SE) | ES | t or χ2 | |
| Self-help beliefs | (N = 173) 2 | (N = 175) | ||||
| Path α3 | .837 (.428) | .291 | 1.96* | .636 (.544) | .018 | 1.17 |
| Path β4 | .066 (.041) | 1.27 | 1.61 | .045 (.032) | 1.20 | 1.40 |
|
|
|
|||||
| Product of αβ | .056 | .029 | ||||
| NT mediation test | z = 1.25 | z = .906 | ||||
| ACL mediation test (.95) | (-.009, .106) | (-.019, .107) | ||||
|
|
|
|||||
| Self-help behaviors | (N = 183) | (N = 175) | ||||
| Path α | 13.7 (6.42) | .319 | 2.13* | 4.95 (5.27) | .137 | 0.94 |
| Path β | .007 (.003) | 1.44 | 2.67** | .020 (.004) | 2.10 | 5.22*** |
|
|
|
|||||
| Product of αβ | .096 | .099 | ||||
| NT mediation test | z = 1.58 | z = .925 | ||||
| ACL mediation test (.95) | (.004, .235) § | (-.121, .316) | ||||
|
|
|
|||||
| Self-efficacy | (N = 170) | (N = 174) | ||||
| Path α | 2.53 (2.29) | .173 | 1.10 | 9.15 (2.99) | .450 | 3.06** |
| Path β | .006 (.008) | 1.14 | 0.75 | .017 (.007) | 1.51 | 2.69** |
|
|
|
|||||
| Product of αβ | .015 | .156 | ||||
| NT mediation test | z = .625 | z = 1.90* | ||||
| ACL mediation test (.95) | (-.023, .075) | (.025, .341)§ | ||||
|
|
|
|||||
| Social support | (N = 166) | (N = 169) | ||||
| Path α | 2.16 (1.43) | .227 | 1.51 | -.427 (1.6) | -.040 | -0.27 |
| Path β | 0.0 (.012) | 1.00 | 0.00 | .023 (.011) | 1.33 | 2.04* |
|
|
|
|||||
| Product of αβ | 0 | -.010 | ||||
| NT mediation test | z = 0 | z = -.27 | ||||
| ACL mediation test (.95) | (-.057, .057) | (-.086, .071) | ||||
|
|
|
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| Commitment to abstinence | (N = 172) | (N = 175) | ||||
| Path α | -.147 (.35) | .932 | 0.18 | .679 (.327) | 1.40 | 4.31* |
| Path β | .582 (.256) | 1.34 | 2.28* | .687 (.256) | 1.41 | 2.68** |
|
|
|
|||||
| Product of αβ | -.086 | .466 | ||||
| NT mediation test | z = .415 | z = 1.64* | ||||
| ACL mediation test (.95) | (-.348, .520) | (.341, .651)§ | ||||
p≤.05,
p≤.01,
p≤.0001,
significant result indicated by .95 CI not crossing 0
ES = Effect Size. Effect Sizes for the models with binary outcomes are represented as odds ratios for a 1 standard deviation unit change in the predictor variable.
The slightly decreased N's reflected in these analyses in comparison to those seen in Table 1 are due to the loss of subjects who had missing data on the covariates included in the models.
Path α for every variable refers to the relationship where treatment condition is the independent variable and the mediator is the outcome variable (all of the test statistics are t's, except for commitment to abstinence where it is a chi-square because it is a binary variable)
Path β represents the relationship where the mediator is the independent variable and total abstinence is the outcome variable (the test statistics are chi-squares because total abstinence is a binary variable)