Table 2

Means, SDs and effect sizes (Cohen's d) for measures of depression, anxiety, psychological flexibility and quality of life

Mean (SD)Effect size, d (95% CI)
Outcome measurePretreatmentPost-treatment6-month follow-upBetween-group, pre–postBetween-group, pre– 6-month follow-upWithin-group, pre–postWithin-group, pre– 6-month follow-up
Total
BDI-II
 BA23.50 (7.85)10.89 (5.92)12.71 (10.56)0.250.031.83 (0.27 to 3.38)**1.19 (−0.87 to 3.24)**
 MF24.68 (9.47)12.94 (10.18)13.09 (12.24)(−1.65 to 2.15)(−2.63 to 2.69)1.21 (−0.95 to 3.38)**1.09 (−1.32 to 3.50)**
PHQ-9
 BA12.53 (4.43)5.83 (3.85)6.77 (5.83)0.280.151.63 (0.71 to 2.56)**1.14 (−0.01 to 2.28)**
 MF13.22 (4.81)7.19 (5.84)7.74 (7.33)(−0.85 to 1.40)(−1.39 to 1.69)1.15 (−0.02 to 2.32)**0.91 (−0.44 to 2.27)**
BAI
 BA14.60 (9.09)8.81 (5.77)8.34 (8.50)0.060.010.76 (−0.95 to 2.47)**0.72 (−1.25 to 2.69)**
 MF13.51 (9.31)9.22 (7.68)8.38 (7.48)(−1.49 to 1.61)(−1.86 to 1.87)0.51 (−1.39 to 2.40)**0.61 (−1.30 to 2.51)**
AAQ-II
 BA27.28 (7.05)21.22 (8.24)20.09 (9.28)0.220.100.80 (−0.89 to 2.50)**0.89 (−0.93 to 2.72)**
 MF28.22 (7.09)23.32 (10.82)21.03 (9.68)(−1.97 to 2.41)(−2.10 to 2.31)0.56 (−1.44 to 2.54)*0.87 (−1.00 to 2.74)**
QOLI
 BA-0.45 (1.38)0.92 (1.66)1.15 (2.40)0.050.010.91 (0.58 to 1.25)**0.84 (0.41 to 1.27) **
 MF−0.20 (1.51)0.84 (1.90)1.13 (2.07)(−0.36 to 0.45)(−0.53 to 0.51)0.62 (0.24 to 0.99)**0.75 (0.36 to 1.15)**
H-LDep
BDI-II
 BA26.87 (7.14)12.00 (6.31)11.81 (10.63)0.420.392.25 (0.33 to 4.18)**1.72 (−0.87 to 4.31)**
 MF28.00 (8.61)15.68 (10.76)16.28 (12.71)(−2.09 to 2.93)(−2.95 to 3.73)1.62 (−0.44 to 3.67)**1.32 (−1.07 to 3.71)**
PHQ-9
 BA15.52 (3.29)6.64 (4.42)6.48 (5.59)0.360.472.34 (1.23 to 3.45)**2.04 (0.73 to 3.35)**
 MF15.57 (3.35)8.60 (6.29)9.60 (7.71)(−1.17 to 1.90)(−1.46 to 2.40)*1.43 (0.13 to 2.74)**1.05 (−0.49 to 2.58)**
BAI
 BA17.43 (9.37)9.18 (6.68)9.62 (8.91)0.200.011.03 (−1.30 to 3.37)**0.87 (−1.77 to 3.52)**
 MF15.57 (9.39)10.68 (8.39)9.72 (7.91)(−1.94 to 2.34)(−2.36 to 2.38)0.56 (−1.80 to 2.92)*0.68 (−1.62 to 2.99)**
AAQ-II
 BA28.27 (7.21)21.68 (8.90)19.33 (9.27)0.440.470.83 (−1.47 to 3.14)**1.11 (−1.28 to 3.49)**
 MF29.04 (6.50)25.87 (10.52)23.56 (9.33)(−2.30 to 3.18)(−2.16 to 3.09)0.38 (−1.90 to 2.65)0.70 (−1.40 to 2.80)*
QOLI
BA−0.51 (1.30)0.78 (1.58)1.25 (2.07)0.260.340.91 (0.50 to 1.33)**1.05 (0.56 to 1.55)**
MF−0.71 (1.18)0.38 (1.58)0.53 (2.23)(−0.70 to 0.18)(−0.95 to 0.27)0.80 (0.44 to 1.17)**0.72 (0.26 to 1.18)**
L-L Dep
BDI-II
 BA18.94 (6.47)9.14 (4.96)14.07 (10.71)−0.51−1.211.74 (−0.25 to 3.72)**0.58 (−2.36 to 3.52)
 MF17.54 (7.09)6.73 (4.86)4.22 (3.63)(−2.36 to 1.34)(−4.13 to 1.71)*1.83 (−0.54 to 4.19)**2.35 (−0.03 to 4.72)**
PHQ-9
 BA8.47 (1.59)4.57 (2.34)7.21 (6.36)−0.23−0.982.06 (1.39 to 2.72)**0.30 (−1.21 to 1.80)
 MF8.15 (3.34)4.00 (2.86)2.56 (1.51)(−1.20 to 0.74)(−2.68 to 0.72)**1.38 (0.19 to 2.59)*2.13 (1.03 to 3.23)**
BAI
 BA10.76 (7.33)8.21 (4.10)6.43 (7.80)−0.56−0.270.43 (−1.64 to 2.51)0.59 (−1.98 to 3.16)
 MF9.08 (7.70)5.91 (4.48)4.67 (4.64)(−2.17 to 1.04)(−2.92 to 2.38)0.51 (−1.95 to 2.98)0.67 (−1.95 to 3.34)**
AAQ-II
 BA26.00 (6.85)20.50 (7.34)21.21 (9.54)−0.37−0.870.80 (−1.61 to 3.21)**0.61 (−2.17 to 3.39)
 MF26.46 (8.21)17.52 (9.54)14.00 (7.07)(−3.52 to 2.78)(−4.26 to 2.52)1.06 (−2.33 to 4.44)*1.68 (−1.42 to 4.78)**
QOLI
 BA−0.37 (1.52)1.14 (1.83)0.97 (2.15)−0.38−0.930.94 (0.37 to 1.50)**0.76 (0.13 to 1.38)*
 MF0.89 (1.61)1.87 (2.24)2.87 (2.10)(−0.38 to 1.14)(−1.77 to 0.10)0.53 (−0.20 to 1.27)1.14 (0.41 to 1.87)
  • *p<0.05.

  • **p<0.01.

  • AAQ-II, Acceptance and Action Questionnaire; BA, behavioural activation; BAI, beck anxiety inventory; BDI-II, beck depression inventory-II; H-L Dep, high-level depression; L-L Dep, low-level depression; MF, mindfulness; PHQ-9, 9-item Patient Health Questionnaire Depression Scale; QOLI, Quality of Life Inventory.