Table 4.
Stepped wedge power for TSOS outcomes
| Continuous outcomes | PTSD Checklist | PHQ-9 | AUDIT | MOS SF-PCS |
|---|---|---|---|---|
| Cluster size at baseline | 40 | 40 | 40 | 40 |
| Cluster size estimation at 12-month (25 % attrition) | 30 | 30 | 30 | 30 |
| Total number of clusters | 24 | 24 | 24 | 24 |
| Alpha | 0.05 | 0.05 | 0.05 | 0.05 |
| Power | 0.8 | 0.8 | 0.8 | 0.8 |
| ICC | 0.02 | 0.0259 | 0.02 | 0.02 |
| Baseline mean (SD) | 50 (15) | 14 (6) | 10 (5) | 50 (10) |
| Autocorrelation | 0.7 | 0.7 | 0.7 | 0.7 |
| Follow-up time points (including baseline) | 4 | 4 | 4 | 4 |
| Minimal detectable effect size | 0.23 | 0.23 | 0.23 | 0.23 |
PTSD posttraumatic stress disorder, PTSD Checklist Civilian Version [58], PHQ-9 Patient Health Questionnaire [82], AUDIT Alcohol Use Disorders Identification Test [85], MOS SF PCS Medical Outcomes Study Short Form Physical Components Summary Score [126], ICC intraclass correlation, SD standard deviation