Twelve RCTs were included in the review and meta-analysis, with 1,092 patients (range 35 to 168).
A small-to-moderate effect was found, favouring mindfulness-based therapy over control, for reduced symptom severity (SMD -0.40, 95% CI -0.54 to -0.26; 10 RCTs); heterogeneity was moderately high (Ι²=71%).
A small-to-moderate effect, favouring mindfulness-based therapy, was found for quality of life (SMD 0.39, 95% CI 0.19 to 0.59; five RCTs); heterogeneity was moderately high (Ι²=70%). Small favourable effects were found for pain (SMD -0.21, 95% CI -0.38 to -0.03; seven RCTs), depression (SMD -0.23, 95% CI -0.40 to -0.07; eight RCTs), and anxiety (SMD -0.20, 95% CI -0.42 to 0.02; five RCTs). Heterogeneity was absent for anxiety (Ι²=0), and low-to-moderate for pain (Ι²=42%) and depression (Ι²=46%).
Funnel plots demonstrated some asymmetry; the authors stated that the assessment of publication bias was inconclusive due to the few trials, substantial heterogeneity, and small effect sizes. Further results were reported.