A Cochrane review included 42 studies of which 35 studies (n=4 788) provided data. The patients had chronic pain, mostly low back pain, musculoskeletal pain, spinal, neck, or shoulder pain, rheumatoid arthritis, fibromyalgia, SLE, temporomandibular joint pain, or osteoarthritis of the knee; trials studying headache and pain due to malignancy were excluded. Cognitive behavioural therapy (CBT) and behaviour therapy were compared with two control conditions (treatment as usual; active control) at two assessment points (immediately following treatment and 6 months or more following treatment). For each comparison, treatment effectiveness was assessed on four outcomes: pain, disability, mood and catastrophic thinking.
Overall there was an absence of evidence for behaviour therapy, except a small improvement in mood immediately following treatment when compared with an active control (SMD -0.47, 95% CI -0.94 to 0.00; 1 study, n=71).
| Outcome | SMD (95% CI) | Participants (studies) |
|---|---|---|
| SMD = standardized mean difference; 0.2 represents a small effect, 0.5 a moderate effect, and 0.8 a large effect | ||
| Pain | -0.21 (-0.37 to -0.05) | 1 148 (16) |
| disability | -0.26 (-0.47 to -0.04) | 1 105 (15) |
| Mood | -0.38 (-0.57 to -0.18) | 899 (12) |
| Catastrophising | -0.53 (-0.76 to -0.31) | 308 (5) |
CBT had small to moderate effects on pain, disability, mood and catastrophising immediately post-treatment when compared with treatment as usual/waiting list (table ), but all except a small effect on mood ( SMD -0.26, 95% CI -0.51 to 0.00; statistical heterogeneity I2=58%; 7 studies, n=637) disappeared at follow-up. CBT had small positive effects on disability (post-treatment SMD -0.19, 95% CI -0.33 to -0.05; 12 studies, n=1 130; follow-up SMD -0.15, 95% CI -0.28 to -0.02; 12 studies, n=1 295) and catastrophizing (post-treatment SMD -0.18, 95% CI -0.36 to 0.00; 6 studies, n=735), but not on pain or mood, when compared with active controls.
Comment: The quality of evidence is downgraded by study limitations (lack of allocation concealment and blinding), and by inconsistency (variability in results).