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Table 4 Stepped wedge power for TSOS outcomes

From: An effectiveness-implementation hybrid trial study protocol targeting posttraumatic stress disorder and comorbidity

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
  1. 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