Table 4.
Repeated-measures analysis of covariance effect of the text message intervention on psychological constructs.
| Item | Control, mean (SD) | Intervention, mean (SD) | Main effect time, F test (df), P valuea |
Interaction time×group, F test (df), P valuea | Significant covariates, Covariate: F (df), P valuea | ||
|
|
BLb | FUc | BL | FU |
|
|
|
| Action self-efficacy | 8.87 (1.37) | 8.65 (2.05) | 8.55 (1.82) | 8.80 (1.49) | .88 | .10 | N/Ad |
| Necessity | 7.67 (1.71) | 7.73 (1.83) | 7.44 (1.63) | 8.15 (1.53) | .72 | F1,165=7.03, .009 | Age: F1,165=7.12, .008 |
| Concerns | 5.73 (1.67) | 5.73 (1.84) | 5.85 (1.65) | 5.56 (1.64) | F1,163=4.17, .043 | .18 | Age: F1,163=7.58, .007 |
| Intention | 9.10 (1.06) | 8.77 (1.62) | 8.61 (1.51) | 9.14 (1.24) | .11 | F1,164=14.31, <.001 | N/A |
| Automaticity | 7.51 (1.71) | 7.51 (1.95) | 7.12 (1.85) | 7.59 (1.77) | .65 | .06 | N/A |
| Maintenance self-efficacy | 8.48 (1.34) | 8.29 (1.44) | 7.91 (1.59) | 8.19 (1.44) | .58 | F1,159=4.68, .032 | N/A |
| Recovery self-efficacye | 8.55 (1.27) | 8.56 (1.56) | 8.10 (1.56) | 8.67 (1.33) | .65 | F1,161=5.50, .02 | N/A |
| Action planning | 6.94 (2.21) | 7.24 (2.10) | 6.88 (2.01) | 7.49 (1.96) | .72 | .32 | Age: F1,161=4.51, .04 |
| Coping planning | 5.88 (1.83) | 6.32 (1.66) | 6.05 (1.63) | 6.70 (1.77) | .11 | .42 | N/A |
| Action control | 7.10 (1.79) | 7.05 (1.81) | 6.99 (1.74) | 7.88 (1.59) | .12 | F1,160=10.80, .001 | N/A |
| Prompts and cues | 5.38 (2.07) | 5.59 (2.09) | 4.91 (1.75) | 6.26 (1.99) | .22 | F1,160=10.31, .002 | N/A |
| Social support | 4.71 (1.55) | 4.74 (1.71) | 4.95 (1.75) | 6.11 (1.65) | .24 | F1, 160=16.40, <.001 | Age: F1,160=4.80, .03 |
| Satisfaction with experienced consequences | 7.78 (1.91) | 7.60 (1.68) | 7.47 (1.81) | 8.16 (1.62) | .45 | F1, 162=9.77, .002 | Age: F1,160=4.73, .03 |
| Risk perception | 8.08 (1.53) | 8.78 (1.76) | 8.07 (1.44) | 8.22 (1.61) | .70 | .53 | N/A |
aTest statistic and degrees of freedom are only reported for P values <.05 in this column.
bBL: baseline.
cFU: follow-up.
dN/A: not applicable (no significant covariates were found).
ePotentially there is less confidence in this result as recovery self-efficacy was significantly different between groups at baseline such that intervention (mean 8.07, SD 1.54) was higher than the control (mean 7.98, SD 1.52; t199=2.59; P=.01).