Skip to main content

Table 3 Means (SD), interaction and main effects of group and time on outcome variables at baseline, immediate, 3 and 6 months’ follow-ups between intervention and control groups in the T-Bak study

From: Effectiveness of a theory-based back care intervention on spine-related behavior among pupils: a school-based randomised controlled trial (T-Bak study)

Variable (score range) Score (mean ± SD) Interaction effect (F): Time×Group Time (F) Group (F)
Baseline Immediate 3-months follow-up 6-months follow-up
Intervention (n = 52) Control (n = 52) Intervention (n = 51) Control (n = 49) Intervention (n = 50) Control (n = 50) Intervention (n = 51) Control (n = 48)
Behavior (6–30) 17.26 ± 4.97 18.30 ± 5.00 26.35 ± 3.61 17.20 ± 5.59 26.68 ± 3.58 18.30 ± 4.84 26.84 ± 2.95 18.08 ± 5.13 29.266* 24.693* 192.985*
P-value 0.36 < 0.001 < 0.001 < 0.001  
Knowledge (0–10) 4.16 ± 1.53 4.30 ± 1.46 7.45 ± 1.83 4.16 ± 1.61 7.82 ± 1.8 4.16 ± 1.53 7.80 ± 1.84 4.35 ± 1.65 29.395* 27.278* 235.725*
P-value 0.65 < 0.001 < 0.001 < 0.001  
Skills (0–46) 13.26 ± 9.37 13.70 ± 10.18 38.75 ± 10.30 13.53 ± 10.18 38.20 ± 11.83 12.48 ± 9.29 37.73 ± 11.63 12.79 ± 9.68 38.556* 34.229* 330.483*
P-value 0.95 < 0.001 < 0.001 < 0.001  
Self-efficacy (4–16) 10.66 ± 2.86 10.2 ± 2.97 14.22 ± 2.17 10.80 ± 2.73 13.68 ± 2.30 9.90 ± 3.11 13.7 ± 1.88 10.44 ± 3.05 9.985* 11.512* 104.833*
P-value 0.66 < 0.001 < 0.001 < 0.001  
Beliefs (6–30) 19.16 ± 4.19 18.08 ± 4.83 26.31 ± 4.39 18.18 ± 4.42 26.32 ± 5.09 18.06 ± 5.02 26.84 ± 4.40 18.67 ± 4.62 14.692* 16.879* 190.811*
P-value 0.24 < 0.001 < 0.001 < 0.001  
  1. SD Standard deviation
  2. *P < 0.001