TABLE 5.
Retention analyses (n = 24).
| Trial design characteristic (independent variable) | Range | Availability of the primary outcome measure(s)
|
Treatment exposure
|
Attendance at follow-up visits
|
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Parameter estimate1 | Test statistic (df) | P-value | Parameter estimate1 | Test statistic (df) | P-value | Parameter estimate1 | Test statistic (df) | P-value | ||
| Type of intervention | Medication | −.161 | F(2,21) = 3.36 | .054 | .023 | F(2,21) = 1.63 | .220 | −.182 | F(2,21) = 5.82 | .010 |
| Psychosocial | .000 | .000 | .000 | |||||||
| Combination | .059 | .132 | −.037 | |||||||
| Type of therapy | Individual | .000 | F(2,21) = .05 | .952 | .000 | F(2,21) = 8.78 | .002 | .000 | F(2,21) = .14 | .874 |
| Group | .005 | −.247 | .016 | |||||||
| Combination | −.021 | .031 | .029 | |||||||
| Number of primary assessment sessions | 1–12 | −.010 | t(22) = −.99 | .331 | ||||||
| Time of last primary assessment (days post-randomization) | 11–365 | −.0003 | t(22) = −.84 | .412 | ||||||
| Number of treatment sessions | 1–24 | −.0001 | t(22) = −.02 | .987 | ||||||
| Duration of treatment | 1 day – 24 weeks2 | .0000 | t(22) = .01 | .992 | ||||||
| Number of CRF pages during treatment3 | 0–702 | .0002 | t(22) = 1.19 | .248 | ||||||
| Number of follow-up visits | 1–8 | −.005 | t(22) = −.30 | .766 | ||||||
| Time of last follow-up visit (days post-randomization) | 84–407 | −.0003 | t(22) = −1.16 | .257 | ||||||
| Number of CRF pages during follow-up visits3 | 10–203 | .0003 | t(22) = .65 | .524 | ||||||
Notes:
1
Value of additional effect (for categorical variables in ANOVA) or of slope (for continuous variables in regression). For categorical variables (ANOVA), SAS sets the parameter value at 0 for the last category, after ordering the categories alphabetically.
2
In one trial, booster treatment sessions occurred up to 52 weeks post-randomization.
3
The amount of information collected on one case report form (CRF) page varies across instruments and trials.